We thank the Australian Research Council (ARC) for ARC Future Fellowship (FT120100101) and ARC Centre of Excellence CE140100036) grants to P.T. and the Mark Wainwright Analytical Centre at UNSW for access to mass spectrometry and NMR facilities.

<ol>
	<li>Griffin, B. A., Adams, S. R., Tsien, R. Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Specific+covalent+labeling+of+recombinant+protein+molecules+inside+live+cells.">Specific covalent labeling of recombinant protein molecules inside live cells.</a> Science. 281, 269-272 (1998).</li><li>Sletten, E. M., Bertozzi, C. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bioorthogonal+chemistry:+Fishing+for+selectivity+in+a+sea+of+functionality.">Bioorthogonal chemistry: Fishing for selectivity in a sea of functionality.</a> Angew. Chem. Int. Ed. 48, 6974-6998 (2009).</li><li>Lyon, R. P., Meyer, D. L., Setter, J. R., Senter, P. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conjugation+of+anticancer+drugs+through+endogenous+monoclonal+antibody+cysteine+residues.">Conjugation of anticancer drugs through endogenous monoclonal antibody cysteine residues.</a> Meth. Enzymol. 502, 123-138 (2012).</li><li>Natarajan, A., Xiong, C. Y., Albrecht, H., DeNardo, G. L., DeNardo, S. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+site-specific+ScFv+PEGylation+for+tumor-targeting+pharmaceuticals.">Characterization of site-specific ScFv PEGylation for tumor-targeting pharmaceuticals.</a> Bioconjug. Chem. 16, 113-121 (2005).</li><li>Hvasanov, D., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-Pot+Synthesis+of+High+Molecular+Weight+Synthetic+Heteroprotein+Dimers+Driven+by+Charge+Complementarity+Electrostatic+Interactions.">One-Pot Synthesis of High Molecular Weight Synthetic Heteroprotein Dimers Driven by Charge Complementarity Electrostatic Interactions.</a> J. Org. Chem. 79, 9594-9602 (2014).</li><li>Thordarson, P., Le Droumaguet, B., Velonia, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Well-defined+protein-polymer+conjugates--synthesis+and+potential+applications.">Well-defined protein-polymer conjugates--synthesis and potential applications.</a> Appl. Microbiol. Biotechnol. 73, 243-254 (2006).</li><li>Lutz, J. F., B&#246;rner, H. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Modern+trends+in+polymer+bioconjugates+design.">Modern trends in polymer bioconjugates design.</a> Prog. Polym. Sci. 33, 1-39 (2008).</li><li>Nicolas, J., Mura, S., Brambilla, D., Mackiewicz, N., Couvreur, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Design,+functionalization+strategies+and+biomedical+applications+of+targeted+biodegradable/biocompatible+polymer-based+nanocarriers+for+drug+delivery.">Design, functionalization strategies and biomedical applications of targeted biodegradable/biocompatible polymer-based nanocarriers for drug delivery.</a> Chem. Soc. Rev. 42, 1147-1235 (2013).</li><li>Wong, C. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymersomes+Prepared+from+Thermoresponsive+Fluorescent+Protein-Polymer+Bioconjugates:+Capture+of+and+Report+on+Drug+and+Protein+Payloads.">Polymersomes Prepared from Thermoresponsive Fluorescent Protein-Polymer Bioconjugates: Capture of and Report on Drug and Protein Payloads.</a> Angew. Chem. Int. Ed. , 5317-5322 (2015).</li><li>Hermanson, G. T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Bioconjugate Techniques. , (2013).</li><li>Li, J., Xu, Q., Cortes, D. M., Perozo, E., Laskey, A., Karlin, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Reactions+of+cysteines+substituted+in+the+amphipathic+N-terminal+tail+of+a+bacterial+potassium+channel+with+hydrophilic+and+hydrophobic+maleimides.">Reactions of cysteines substituted in the amphipathic N-terminal tail of a bacterial potassium channel with hydrophilic and hydrophobic maleimides.</a> Proc. Natl. Acad. Sci. U.S.A. 99 (18), 11605-11610 (2002).</li><li>Peterson, J. R., Smith, T. A., Thordarson, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Synthesis+and+room+temperature+photo-induced+electron+transfer+in+biologically+active+bis(terpyridine)ruthenium(II)-cytochrome+c+bioconjugates+and+the+effect+of+solvents+on+the+bioconjugation+of+cytochrome+c.">Synthesis and room temperature photo-induced electron transfer in biologically active bis(terpyridine)ruthenium(II)-cytochrome c bioconjugates and the effect of solvents on the bioconjugation of cytochrome c.</a> Org. Biomol. Chem. 8, 151-162 (2010).</li><li>Borges, C. R., Sherma, N. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Techniques+for+the+Analysis+of+Cysteine+Sulfhydryls+and+Oxidative+Protein+Folding.">Techniques for the Analysis of Cysteine Sulfhydryls and Oxidative Protein Folding.</a> Antioxid. Redox Signal. (3), 1-21 (2014).</li><li>Peterson, J. R., Thordarson, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimising+the+purification+of+terpyridine-cytochrome+c+bioconjugates.">Optimising the purification of terpyridine-cytochrome c bioconjugates.</a> Chiang Mai J. Sci. 36 (2), 236-246 (2009).</li><li>Hvasanov, D., Mason, A. F., Goldstein, D. C., Bhadbhade, M., Thordarson, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimising+the+synthesis,+polymer+membrane+encapsulation+and+photoreduction+performance+of+Ru(II)-+and+Ir(III)-bis(terpyridine)+cytochrome+c+bioconjugates.">Optimising the synthesis, polymer membrane encapsulation and photoreduction performance of Ru(II)- and Ir(III)-bis(terpyridine) cytochrome c bioconjugates.</a> Org. Biomol. Chem. 11 (28), 4602-4612 (2013).</li><li>Signor, L., Boeri Erba, E. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Matrix-assisted+Laser+Desorption/Ionization+Time+of+Flight+(MALDI-TOF)+Mass+Spectrometric+Analysis+of+Intact+Proteins+Larger+than+100+kDa.">Matrix-assisted Laser Desorption/Ionization Time of Flight (MALDI-TOF) Mass Spectrometric Analysis of Intact Proteins Larger than 100 kDa.</a> J. Vis. Exp. , e50635 (2013).</li><li>Foucher, M., Verdi&#232;re, J., Lederer, F., Slonimski, P. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=On+the+presence+of+a+non-trimethylated+iso-1+cytochrome+c+in+a+wild-type+strain+of+Saccharomyces+cerevisiae).">On the presence of a non-trimethylated iso-1 cytochrome c in a wild-type strain of Saccharomyces cerevisiae).</a> Eur. J. Biochem. 31, 139-143 (1972).</li><li>M&#252;ller, M., Azzi, A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Selective+labeling+of+beef+heart+cytochrome+oxidase+subunit+III+with+eosin-5-maleimide.">Selective labeling of beef heart cytochrome oxidase subunit III with eosin-5-maleimide.</a> FEBS Lett. 184 (1), 110-114 (1985).</li><li>Shen, B. Q., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conjugation+site+modulates+the+in+vivo+stability+and+therapeutic+activity+of+antibody-drug+conjugates.">Conjugation site modulates the in vivo stability and therapeutic activity of antibody-drug conjugates.</a> Nat. Biotechnol. 30 (2), 184-189 (2012).</li></ol>

The authors have nothing to disclose.

טיהור של חומרים החל לפני bioconjugation הוא בעל חשיבות עליונה. חלבונים שהושגו ממקורות מסחריים רקומביננטי בדרך כלל מכילים isoforms אחר של החלבון של עניין, אשר יכולה להיות כימית תגובתיות משטח שונה. לדוגמא, ב bioconjugation המתואר, ג CYT הזמין המסחרי מכיל תערובת של שניהם 12,14,17 ?...

Bioconjugation עוסק בחיבור קוולנטית biomolecule אחד עם השני או עם מולקולה סינתטית כגון צבע, סמים או פולימר. שיטות bioconjugation חלבון נמצאות כיום בשימוש נרחב קבוצות מחקר כימיה, ביולוגיה וננוטכנולוגיה רבות עם יישומים החל תיוג פלורסנט לצבוע 1,2, מה שהופך של חלבון (נוגדן) -prodrugs 3 (conjugates תרופת נוגדן - ADC) סינתזה של הדימרים חלבון 4,5 , ועד כלאי חלבון-פולימר הרכבה עצמית 6,7 המשמשים כימיה nanomedicine 8 ומערכות 9. ספציפית של הכימיה המשמש bioconjugation, בעוד לא תמיד קריטי, הוא בעל חשיבות עליונה עבור bioconjugates חלבון הפונקציונלי ביותר, כדי לא להפריע את האתר הפעיל של חלבון המטרה. תגובת bioconjugation האידיאלית צריכה לקיים מספר קריטריונים, כולל: i) מיקוד אתרים נדירים או ייחודיים על החלבון של עניין,ii) להיות סלקטיבית כלפי יעד זה, iii) להמשיך בתנאים שאינם denaturing להימנע חלבון התגלגלות iv) להיות גבוה מניב כמו חלבון המטרה הוא בדרך כלל זמין רק בריכוז תת-millimolar. Maleimide - ציסטאין מיכאל בנוסף מתקרב להגשמת כל הקריטריונים הללו, ויש לו מסיבה זו טענה ארוכה מעמד מיוחד בתחום כימית bioconjugate 10. הסיבה לכך היא כי אני) חלבונים רבים המכילים שאריות ציסטאין היחיד על פני השטח שלהם יכול להיות מהונדסים גנטית שם, ב) על pH הנכון התגובה היא מאוד סלקטיבית כלפי ציסטאין, iii) זה יתנהל למישרין מאגרים מימיים iv) זה מהר מאוד עם קבוע של maleimides שיעור מסדר שני חלבונים המכילים ציסטאין דיווחו יעלה 5,000 M -1 שניות -1 ובמקרים מסוימים 11. ספקו את החלבון של עניין יכול לסבול קטנה (≈ 5-10%) כמות אורגן שיתוף ממסים 12, כמעט כל צבען פונקציונלי maleimide, פוlymer ומשטחים או חלבון אחר יכול להיות קשור חלבונים. בנוסף, maleimides הם ספציפי יותר עבור cysteines על חלבונים מאשר iodoacetamides, אשר נוטה יותר להגיב עם נוקלאופיל אחר ב- pH הגבוהה; ויציבה יותר מאשר גזרה בבניינים מבוססי דיסולפיד אשר צריך להישמר ב- pH חומצי כדי למנוע חילופי דיסולפיד 13. כאן אנו מדווחים פרוטוקול גנרי הנטייה של מולקולות פונקציונלי maleimide לחלבון המכיל שאריות ציסטאין יחידות באמצעות התגובה בין Ru (II) כרומופור מבוסס ואת ציטוכרום C חלבון חיזור כדוגמא. פרוטוקול זה הוא החלים באופן שווה על רוב החלבונים אחרים המכילים שאריות ציסטאין משטח נגישות ויעד maleimide הפונקציונלית המקביל, בין אם הוא חלבון אחר, צבע ניאון, כרומופור או פולימר סינטטי.

<table border="0" cellpadding="0" cellspacing="0" width="913">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">sodium dihydrogen phosphate</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">71496</td>
			<td style="width:263px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">sodium hydroxide</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">71691</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">sodium chloride</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">73575</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">cytochrome c, from saccaromyces cerevisiae</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">C2436</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">dithiothreitol</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">43819</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">TSKgel SP-5PW</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">Tosoh SP-5PW, 07161</td>
			<td>3.3 mL strong cation exchange column</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Amicon Ultra-15&#160;</td>
			<td style="width:196px;">Merck-Millipore</td>
			<td style="width:151px;">UFC900308</td>
			<td>3.5 kDa spin filter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Slide-A-Lyzer mini dialysis units</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td style="width:151px;">66333</td>
			<td>3.5 kDa dialysis cassetes</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">Ru(II) bisterpyridine maleimide</td>
			<td style="width:196px;">Lab made</td>
			<td style="width:151px;"></td>
			<td>see ref (14)</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">acetonitrile</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">A3396</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">ethylenediaminetetraacetic acid</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">03609</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">tris(2-carboxyethyl)phosphine hydrochloride&#160;</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">93284</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">imidazole</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">56749</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">nickel acetate</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">244066</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">AcroSep IMAC Hypercell column</td>
			<td style="width:196px;">Pall</td>
			<td style="width:151px;">via VWR: 569-1008</td>
			<td>1 mL IMAC column</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">0.2 micron cellulose membrane filter</td>
			<td style="width:196px;">Whatman</td>
			<td style="width:151px;">Z697958</td>
			<td>47 mm filter for buffers</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">0.2 micron PVDF membrane filter</td>
			<td style="width:196px;">Merck-Millipore</td>
			<td style="width:151px;">SLGV013SL</td>
			<td>syringe filters for proteins</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">hydrochloric acid</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">84426</td>
			<td>extremely corrosive! Use caution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">caffeic acid</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">60018</td>
			<td>MALDI matrix</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">trifluoroacetic acid</td>
			<td style="width:196px;">Sigma-Aldrich</td>
			<td style="width:151px;">91707</td>
			<td>extremely corrosive! Use caution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">SimplyBlue SafeStain</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td style="width:151px;">LC6060</td>
			<td>Coomassie blue solution</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">NuPAGE Novex 12% Bis-Tris Gel</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td style="width:151px;">NP0342BOX</td>
			<td>precast protein gels</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">SeeBlue Plus2 Pre-stained Protein Standard</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td style="width:151px;">LC5925</td>
			<td>premade protein ladder</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">NuPAGE LDS Sample Buffer (4X)</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td style="width:151px;">NP0008</td>
			<td>premade gel sample buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">NuPAGE Sample Reducing Agent (10X)</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td style="width:151px;">NP0004</td>
			<td>premade gel reducing agent</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">NuPAGE MES SDS Running Buffer (20X)</td>
			<td style="width:196px;">Thermo Scientific</td>
			<td style="width:151px;">NP0002</td>
			<td>premade gel running buffer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">Voyager DE STR MALDI reflectron TOF MS</td>
			<td style="width:196px;">Applied Biosystems</td>
			<td style="width:151px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">Acta FPLC</td>
			<td style="width:196px;">GE</td>
			<td style="width:151px;"></td>
			<td>Fast Protein Liquid Chromatography</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">Cary 50 Bio Spectrophotometer</td>
			<td style="width:196px;">Varian-Agilent</td>
			<td style="width:151px;"></td>
			<td>UV-Vis</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">Milli-Q ultrapure water dispenser</td>
			<td style="width:196px;">Merck-Millipore</td>
			<td style="width:151px;"></td>
			<td>ultrapure water</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:304px;">Low volume UV-Vis Cuvette</td>
			<td style="width:196px;">Hellma</td>
			<td style="width:151px;">105-201-15-40</td>
			<td>100 microliter cuvette</td>
		</tr>
	</tbody>
</table>

synthesis of protein bioconjugates via cysteine-maleimide chemistry

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the development of antibody drug conjugates (ADCs) and nanomedicine, fluorescent microscopy and systems chemistry. For many of these applications, specificity of the bioconjugation method used is of prime concern. The Michael addition of maleimides with cysteine(s) on the target proteins is highly selective and proceeds rapidly under mild conditions, making it one of the most popular methods for protein bioconjugation.
We demonstrate here the modification of the only surface-accessible cysteine residue on yeast cytochrome c with a ruthenium(II) bisterpyridine maleimide. The protein bioconjugation is verified by gel electrophoresis and purified by aqueous-based fast protein liquid chromatography in 27% yield of isolated protein material. Structural characterization with MALDI-TOF MS and UV-Vis is then used to verify that the bioconjugation is successful. The protocol shown here is easily applicable to other cysteine - maleimide coupling of proteins to other proteins, dyes, drugs or polymers.

הסינתזה של bioconjugates אושר על ידי שלוש שיטות עיקריות: זמן יינון Desorption לייזר בסיוע מטריקס של ספקטרומטריית מסה טיסה (MALDI-TOF MS), ג&#39;ל אלקטרופורזה polyacrylamide, ו-סגול-גלוי (UV-Vis) ספקטרוסקופיה, כפי שמוצג איורים 2, 3 ו -4. עלייה מונית המתאימה המסה של ה...

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Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

פרוטוקול זה מפרט את הצעדים החשובים הנדרשים bioconjugation של ציסטאין המכיל חלבון על maleimide, כוללים טיהור מגיבה, תנאי תגובה, טיהור bioconjugate ואפיון bioconjugate.

סינתזה של חלבון Bioconjugates<em&gt; דרך</em&gt; כימיה ציסטאין-maleimide

The chemical linking or bioconjugation of proteins to fluorescent dyes, drugs, polymers and other proteins has a broad range of applications, such as the ...

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Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

Chemical Applications of Statistical Analyses

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38.2K Views.  The University of New South Wales.  פרוטוקול זה מפרט את הצעדים החשובים הנדרשים bioconjugation של ציסטאין המכיל חלבון על maleimide, כוללים טיהור מגיבה, תנאי תגובה, טיהור bioconjugate ואפיון bioconjugate. 

Video: Synthesis of Protein Bioconjugates via Cysteine-maleimide Chemistry

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides (CHIPS)

The direct functionalization of C-H bonds is an important and long standing goal in organic chemistry. Such transformations can be very powerful in order to streamline synthesis by saving steps, time and material compared to conventional methods that require the introduction and removal of activating or directing groups. Therefore, the functionalization of C-H bonds is also attractive for green chemistry. Under oxidative conditions, two C-H bonds or one C-H and one heteroatom-H bond can be transformed to C-C and C-heteroatom bonds, respectively. Often these oxidative coupling reactions require synthetic oxidants, expensive catalysts or high temperatures. Here, we describe a two-step procedure to functionalize indole derivatives, more specifically tetrahydrocarbazoles, by C-H amination using only elemental oxygen as oxidant. The reaction uses the principle of C-H functionalization via Intermediate PeroxideS (CHIPS). In the first step, a hydroperoxide is generated oxidatively using visible light, a photosensitizer and elemental oxygen. In the second step, the N-nucleophile, an aniline, is introduced by Br&#248;nsted-acid catalyzed activation of the hydroperoxide leaving group. The products of the first and second step often precipitate and can be conveniently filtered off. The synthesis of a biologically active compound is shown.

Synthesis of Antiviral Tetrahydrocarbazole Derivatives by Photochemical and Acid-catalyzed C-H Functionalization via Intermediate Peroxides CHIPS

A two-step procedure for the synthesis of pharmaceutically active indole-derivatives by C-H functionalization with anilines is described, using photo- and Br&#248;nsted acid catalysis.

סינתזה של נגזרות אנטי Tetrahydrocarbazole ידי פוטו וFunctionalization CH זרז חומצה באמצעות חמצניים ביניים (CHIPS)

The direct functionalization of C-H bonds is an important and long standing goal in organic chemistry. Such transformations can be very powerful in order ...

Synthesis and Characterization of Functionalized Metal-organic Frameworks

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and technological applications. Their signature property is their ultrahigh porosity, which however imparts a series of challenges when it comes to both constructing them and working with them. Securing desired MOF chemical and physical functionality by linker/node assembly into a highly porous framework of choice can pose difficulties, as less porous and more thermodynamically stable congeners (e.g., other crystalline polymorphs, catenated analogues) are often preferentially obtained by conventional synthesis methods. Once the desired product is obtained, its characterization often requires specialized techniques that address complications potentially arising from, for example, guest-molecule loss or preferential orientation of microcrystallites. Finally, accessing the large voids inside the MOFs for use in applications that involve gases can be problematic, as frameworks may be subject to collapse during removal of solvent molecules (remnants of solvothermal synthesis). In this paper, we describe synthesis and characterization methods routinely utilized in our lab either to solve or circumvent these issues. The methods include solvent-assisted linker exchange, powder X-ray diffraction in capillaries, and materials activation (cavity evacuation) by supercritical CO2 drying. Finally, we provide a protocol for determining a suitable pressure region for applying the Brunauer-Emmett-Teller analysis to nitrogen isotherms, so as to estimate surface area of MOFs with good accuracy.

Synthesis, activation, and characterization of intentionally designed metal-organic framework materials is challenging, especially when building blocks are incompatible or unwanted polymorphs are thermodynamically favored over desired forms. We describe how applications of solvent-assisted linker exchange, powder X-ray diffraction in capillaries and activation via supercritical CO2 drying, can address some of these challenges.

מסגרות סינתזה ואפיון של פונקציונליות מתכת אורגנית

Metal-organic frameworks have attracted extraordinary amounts of research attention, as they are attractive candidates for numerous industrial and ...

Synthesis and Reaction Chemistry of Nanosize Monosodium Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the material with Au(III) ions. The synthesis method was derived from a sol-gel process used to produce micron-sized monosodium titanate (MST), with several key modifications, including altering reagent concentrations, omitting a particle seed step, and introducing a non-ionic surfactant to facilitate control of particle formation and growth. The resultant nMST material exhibits spherical-shaped particle morphology with a monodisperse distribution of particle diameters in the range from 100 to 150&#160;nm. The nMST material was found to have a Brunauer-Emmett-Teller (BET) surface area of 285 m2g-1, which is more than an order of magnitude higher than the micron-sized MST. The isoelectric point of the nMST measured 3.34 pH units, which is a pH unit lower than that measured for the micron-size MST. The nMST material was found to serve as an effective ion exchanger under weakly acidic conditions for the preparation of an Au(III)-exchange nanotitanate. In addition, the formation of the corresponding peroxotitanate was demonstrated by reaction of the nMST with hydrogen peroxide.

The surfactant mediated sol-gel synthesis of nanosized monosodium titanate is described, along with preparation of the corresponding peroxide modified material. An ion-exchange reaction with Au(III) is also presented.

כימית סינתזת תגובה של nanosize מונוסודיום Titanate

This paper describes the synthesis and peroxide-modification of nanosize monosodium titanate (nMST), along with an ion-exchange reaction to load the ...

The Synthesis of [Sn10(Si(SiMe3)3)4]2- Using a Metastable Sn(I) Halide Solution Synthesized via a Co-condensation Technique

The number of well-characterized metalloid tin clusters, synthesized by applying the disproportionation of a metastable Sn(I) halide in the presence of a sterically demanding ligand, has increased in recent years. The metastable Sn(I) halide is synthesized at&#160;&#34;outer space conditions&#34; via the preparative co-condensation technique. Thereby, the subhalide is synthesized in an oven at high temperatures, around 1,300 &#176;C, and at reduced pressure by the reaction of elemental tin with hydrogen halide gas (e.g., HCl). The subhalide (e.g., SnCl) is trapped within a matrix of an inert solvent, like toluene at -196 &#176;C. Heating the solid matrix to -78 &#176;C gives a metastable solution of the subhalide. The metastable subhalide solution is highly reactive but can be stored at -78 &#176;C for several weeks. On heating the solution to room temperature, a disproportionation reaction occurs, leading to elemental tin and the corresponding dihalide. By applying bulky ligands like Si(SiMe3)3, the intermediate metalloid cluster compounds can be trapped before complete disproportionation to elemental tin. Hence, the reaction of a metastable Sn(I)Cl solution with Li-Si(SiMe3)3 gives [Sn10(Si(SiMe3)3)4]2- 1 as black crystals in high yield. 1 is formed via a complex reaction sequence including salt metathesis, disproportionation, and degradation of larger clusters. Further, 1 can be analyzed by various methods like NMR or single crystal X-ray structure analysis.

The Synthesis of [Sn10SiSiMe334]2- Using a Metastable SnI Halide Solution Synthesized via a Co-condensation Technique

The disproportionation reaction of a metastable Sn(I) chloride solution, obtained via the preparative co-condensation technique, is used for the synthesis of a metalloid tin cluster compound.

הסינתזה של [Sn<sub&gt; 10</sub&gt; (Si (Sime<sub&gt; 3</sub&gt;)<sub&gt; 3</sub&gt;)<sub&gt; 4</sub&gt;]<sup&gt; 2</sup<sup&gt; -</sup&gt; שימוש metastable Sn (I) פתרון Halide מסונתז באמצעות טכניקה Co-עיבוי

The number of well-characterized metalloid tin clusters, synthesized by applying the disproportionation of a metastable Sn(I) halide in the presence of a ...

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular methodology for applications in various fields and for different research purposes. The procedure described herein focuses on the synthesis, purification, and characterization of dodecamers of RNA 5&#39;-[CUA CGG AAU CAU]-3&#39; containing zero, one, or two modifications located at the C2&#39;-O-position. The probes are based on 2-thiophenylmethyl groups, incorporated into RNA nucleotides via standard organic synthesis and introduced into the corresponding oligonucleotides via their respective phosphoramidites. This report makes use of phosphoramidite chemistry via the four canonical nucleobases (Uridine (U), Cytosine (C), Guanosine (G), Adenosine (A)), as well as 2-thiophenylmethyl functionalized nucleotides modified at the 2&#39;-O-position; however, the methodology is amenable for a large variety of modifications that have been developed over the years. The oligonucleotides were synthesized on a controlled-pore glass (CPG) support followed by cleavage from the resin and deprotection under standard conditions, i.e., a mixture of ammonia and methylamine (AMA) followed by hydrogen fluoride/triethylamine/N-methylpyrrolidinone. The corresponding oligonucleotides were purified via polyacrylamide electrophoresis (20% denaturing) followed by elution, desalting, and isolation via reversed-phase chromatography (Sep-pak, C18-column). Quantification and structural parameters were assessed via ultraviolet-visible (UV-vis) and circular dichroism (CD) photometric analysis, respectively. This report aims to serve as a resource and guide for beginner and expert researchers interested in embarking in this field. It is expected to serve as a work-in-progress as new technologies and methodologies are developed. The description of the methodologies and techniques within this document correspond to a DNA/RNA synthesizer (refurbished and purchased in 2013) that uses phosphoramidite chemistry.

Protocol for the Solid-phase Synthesis of Oligomers of RNA Containing a 2'-O-thiophenylmethyl Modification and Characterization via Circular Dichroism

This article provides a detailed procedure on the solid-phase synthesis, purification, and characterization of dodecamers of RNA modified at the C2&#39;-O-position. UV-vis and circular dichroism photometric analyses are used to quantify and characterize structural aspects, i.e., single-strands or double-strands.

Protocol עבור שלב מוצק סינתזה של אוליגומרים של רנ&quot;א המכיל 2 &#39;<em&gt; הו</em&gt; שינוי ואפיון של תיאופנילמתיל באמצעות דיכרואיזם מעגלי

Solid-phase synthesis has been used to obtain canonical and modified polymers of nucleic acids, specifically of DNA or RNA, which has made it a popular ...

Synthesis of Substrate-Bound Au Nanowires Via an Active Surface Growth Mechanism

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a challenge, as it requires asymmetric growth of symmetric crystals. Here, we report a distinctive synthesis of substrate-bound Au nanowires. This template-free synthesis employs thiolated ligands and substrate adsorption to achieve the continuous asymmetric deposition of Au in solution at ambient conditions. The thiolated ligand prevented the Au deposition on the exposed surface of the seeds, so the Au deposition only occurs at the interface between the Au seeds and the substrate. The side of the newly deposited Au nanowires is immediately covered with the thiolated ligand, while the bottom facing the substrate remains ligand-free and active for the next round of Au deposition. We further demonstrate that this Au nanowire growth can be induced on various substrates, and different thiolated ligands can be used to regulate the surface chemistry of the nanowires. The diameter of the nanowires can also be controlled with mixed ligands, in which another &#34;bad&#34; ligand could turn on the lateral growth. With the understanding of the mechanism, Au nanowire-based nanostructures can be designed and synthesized.

We report a solution-based method to synthesize substrate-bound Au nanowires. By tuning the molecular ligands used during the synthesis, the Au nanowires can be grown from various substrates with different surface properties. Au nanowire-based nanostructures can also be synthesized by adjusting the reaction parameters.

סינתזה של המצע מכורך Au Nanowires באמצעות מנגנון הצמיחה הפעילה משטח

Advancing synthetic capabilities is important for the development of nanoscience and nanotechnology. The synthesis of nanowires has always been a ...

A Rapid Synthesis Method for Au, Pd, and Pt Aerogels Via Direct Solution-Based Reduction

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various precursor noble metal ions with reducing agents in a 1:1 (v/v) ratio results in the formation of metal gels within seconds to minutes compared to much longer synthesis times for other techniques such as sol-gel. Conducting the reduction step in a microcentrifuge tube or small volume conical tube facilitates a proposed nucleation, growth, densification, fusion, equilibration model for gel formation, with final gel geometry smaller than the initial reaction volume. This method takes advantage of the vigorous hydrogen gas evolution as a by-product of the reduction step, and as a consequence of reagent concentrations. The solvent accessible specific surface area is determined with both electrochemical impedance spectroscopy and cyclic voltammetry. After rinsing and freeze drying, the resulting aerogel structure is examined with scanning electron microscopy, X-ray diffractometry, and nitrogen gas adsorption. The synthesis method and characterization techniques result in a close correspondence of aerogel ligament sizes. This synthesis method for noble metal aerogels demonstrates that high specific surface area monoliths may be achieved with a rapid and direct reduction approach.

A rapid, direct solution-based reduction synthesis method to obtain Au, Pd, and Pt aerogels is presented.

שיטה מהירה סינתזה Au, Pd ו- Pt Aerogels באמצעות הפחתת המבוסס על פתרון ישיר

Here, a method to synthesize gold, palladium, and platinum aerogels via a rapid, direct solution-based reduction is presented. The combination of various ...

Synthesis of Esters Via a Greener Steglich Esterification in Acetonitrile

The Steglich esterification is a widely-used reaction for the synthesis of esters from carboxylic acids and alcohols. While efficient and mild, the reaction is commonly performed using chlorinated or amide solvent systems, which are hazardous to human health and the environment. Our methodology utilizes acetonitrile as a greener and less hazardous solvent system. This protocol exhibits rates and yields that are comparable to traditional solvent systems and employs an extraction and wash sequence that eliminates the need for the purification of the ester product via column chromatography. This general method can be used to couple a variety of carboxylic acids with 1&#176; and 2&#176; aliphatic alcohols, benzylic and allylic alcohols, and phenols to obtain pure esters in high yields. The goal of the protocol detailed here is to provide a greener alternative to a common esterification reaction, which could serve useful for ester synthesis in both academic and industrial applications.

A modified Steglich esterification reaction was used to synthesize a small library of ester derivatives with primary and secondary alcohols. The methodology uses a non-halogenated and greener solvent, acetonitrile, and enables product isolation in high yields without the need for chromatographic purification.

סינתזה של אסטרים ויה Esterification Steglich ירוק יותר ב- Acetonitrile

The Steglich esterification is a widely-used reaction for the synthesis of esters from carboxylic acids and alcohols. While efficient and mild, the ...

Escherichia coli-Based Cell-Free Protein Synthesis: Protocols for a robust, flexible, and accessible platform technology

Over the last 50 years, Cell-Free Protein Synthesis (CFPS) has emerged as a powerful technology to harness the transcriptional and translational capacity of cells within a test tube. By obviating the need to maintain the viability of the cell, and by eliminating the cellular barrier, CFPS has been foundational to emerging applications in biomanufacturing of traditionally challenging proteins, as well as applications in rapid prototyping for metabolic engineering, and functional genomics. Our methods for implementing an E. coli-based CFPS platform allow new users to access many of these applications. Here, we describe methods to prepare extract through the use of enriched media, baffled flasks, and a reproducible method of tunable sonication-based cell lysis. This extract can then be used for protein expression capable of producing 900 &#181;g/mL or more of super folder green fluorescent protein (sfGFP) in just 5 h from experimental setup to data analysis, given that appropriate reagent stocks have been prepared beforehand. The estimated startup cost of obtaining reagents is $4,500 which will sustain thousands of reactions at an estimated cost of $0.021 per &#181;g of protein produced or $0.019 per &#181;L of reaction. Additionally, the protein expression methods mirror the ease of the reaction setup seen in commercially available systems due to optimization of reagent pre-mixes, at a fraction of the cost. In order to enable the user to leverage the flexible nature of the CFPS platform for broad applications, we have identified a variety of aspects of the platform that can be tuned and optimized depending on the resources available and the protein expression outcomes desired.

Escherichia coli-Based Cell-Free Protein Synthesis: Protocols for a robust, flexible, and accessible platform technology

This protocol details the steps, costs, and equipment necessary to generate E. coli-based cell extracts and implement in vitro protein synthesis reactions within 4 days or less. To leverage the flexible nature of this platform for broad applications, we discuss reaction conditions that can be adapted and optimized.

Escherichia coli-המבוסס על סינתזת החלבון ללא תא: פרוטוקולים עבור טכנולוגיית פלטפורמה חזקים, גמישים ונגישים

Over the last 50 years, Cell-Free Protein Synthesis (CFPS) has emerged as a powerful technology to harness the transcriptional and translational capacity ...

Synthesis of Monodisperse Cylindrical Nanoparticles via Crystallization-driven Self-assembly of Biodegradable Block Copolymers

The production of monodisperse cylindrical micelles is a significant challenge in polymer chemistry. Most cylindrical constructs formed from diblock copolymers are produced by one of three techniques: thin film rehydration, solvent switching or polymerization-induced self-assembly, and produce only flexible, polydisperse cylinders. Crystallization-driven self-assembly (CDSA) is a method which can produce cylinders with these properties, by stabilizing structures of a lower curvature due to the formation of a crystalline core. However, the living polymerization techniques by which most core-forming blocks are formed are not trivial processes and the CDSA process may yield unsatisfactory results if carried out incorrectly. Here, the synthesis of cylindrical nanoparticles from simple reagents is shown. The drying and purification of reagents prior to a ring-opening polymerization of &#949;-caprolactone catalyzed by diphenyl phosphate is described. This polymer is then chain extended by methyl methacrylate (MMA) followed by N,N-dimethyl acrylamide (DMA) using reversible addition&#8722;fragmentation chain-transfer (RAFT) polymerization, affording a triblock copolymer that can undergo CDSA in ethanol. The living CDSA process is outlined, the results of which yield cylindrical nanoparticles up to 500 nm in length and a length dispersity as low as 1.05. It is anticipated that these protocols will allow others to produce cylindrical nanostructures and elevate the field of CDSA in the future.

Crystallization-driven self-assembly (CDSA) displays the unique ability to fabricate cylindrical nanostructures of narrow length distributions. The organocatalyzed ring-opening polymerization of &#949;-caprolactone and subsequent chain extensions of methyl methacrylate and N,N-dimethyl acrylamide are demonstrated. A living CDSA protocol that produces monodisperse cylinders up to 500 nm in length is outlined.

סינתזה של חלקיקים מונוטהתפזר גלילי באמצעות התגבשות עצמית מונחה-הרכבה של סופולימרים מתכלים לחסום

The production of monodisperse cylindrical micelles is a significant challenge in polymer chemistry. Most cylindrical constructs formed from diblock ...