Name: laser-free hydroxyl radical protein footprinting to perform higher order structural analysis of proteins
Uploaded: 2021-06-04T13:00:00
Description: Watch this Scientific Journal Video about Laser-free Hydroxyl Radical Protein Footprinting to Perform Higher Order Structural Analysis of Proteins at JoVE.com

This work was funded by the National Institute of General Medical Sciences (R43GM125420 and R44GM125420).

1. Installing the capillary tube
<ol>
	<li>Using a silica cleaving stone, cleave 250 &#181;m inner diameter (ID) silica capillary to 27 inches. Check the capillary ends for a clean, straight cut.</li>
	<li>Create two windows roughly 15 mm in length by burning away the polyimide coating. Starting from the &#8220;lower end&#8221; make the first photolysis window 90 mm away from the &#8220;lower end&#8221; and the second dosimeter window 225 mm away from the &#8220;lower end&#8221;. 
	NOTE: Once the coating is burned...

<ol>
	<li>Nagarkar, R. P., Murphy, B. M., Yu, X., Manning, M. C., Al-Azzam, W. A. <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+protein+higher+order+structure+using+vibrational+circular+dichroism+spectroscopy.">Characterization of protein higher order structure using vibrational circular dichroism spectroscopy.</a> Current Pharmaceutical Biotechnology. 14 (2), 199-208 (2013).</li><li>Giezen, T. J., Schneider, C. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Safety+assessment+of+biosimilars+in+Europe:+a+regulatory+perspective.">Safety assessment of biosimilars in Europe: a regulatory perspective.</a> Generics and Biosimilars Initiative Journal. , 1-8 (2014).</li><li>Giezen, T. J., Mantel-Teeuwisse, A. K., Strauss, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Safety-related+regulatory+actions+for+biologicals+approved+in+the+United+States+and+the+Europena+Union.">Safety-related regulatory actions for biologicals approved in the United States and the Europena Union.</a> Journal of the American Medical Society. 300 (16), 1887-1896 (2008).</li><li>Gabrielson, J. P., Weiss, W. F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Technical+decision-making+with+higher+order+structure+data:+starting+a+new+dialogue.">Technical decision-making with higher order structure data: starting a new dialogue.</a> Journal of Pharmaceutical Sciences. 104 (1), 1240-1245 (2015).</li><li>Brenowitz, M., Erie, D. A., Chance, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Catching+RNA+polymerase+in+the+act+of+binding:+intermediates+in+transcription+illuminated+by+synchrotron+footprinting.">Catching RNA polymerase in the act of binding: intermediates in transcription illuminated by synchrotron footprinting.</a> Proceedings of the National Academy of Sciences U S A. 102 (13), 4659-4660 (2005).</li><li>Guan, J. Q., Takamoto, K., Almo, S. C., Reisler, E., Chance, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structure+and+dynamics+of+the+actin+filament.">Structure and dynamics of the actin filament.</a> Biochemistry. 44 (9), 3166-3175 (2005).</li><li>Hambly, D. M., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+flash+photochemical+oxidataion+to+locate+heme+binding+and+conformataional+changes+in+myoglobin.">Laser flash photochemical oxidataion to locate heme binding and conformataional changes in myoglobin.</a> International Journal of Mass Spectrometry. 259 (2007), 124-129 (2007).</li><li>Li, K. S., Shi, L., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+Spectrometry-Based+Fast+Photochemical+Oxidation+of+Proteins+(FPOP)+for+Higher+Order+Structure+Characterization.">Mass Spectrometry-Based Fast Photochemical Oxidation of Proteins (FPOP) for Higher Order Structure Characterization.</a> Accounts of Chemical Research. 51 (3), 736-744 (2018).</li><li>Watson, C., Sharp, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Conformational+Analysis+of+Therapeutic+Proteins+by+Hydroxyl+Radical+Protein+Footprinting.">Conformational Analysis of Therapeutic Proteins by Hydroxyl Radical Protein Footprinting.</a> American Association of Pharmaceutical Scientists Journal. 14 (2), 206-217 (2012).</li><li>Deperalta, G., 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=Structural+analysis+of+a+therapeutic+monoclonal+antibody+dimer+by+hydroxyl+radical+footprinting.">Structural analysis of a therapeutic monoclonal antibody dimer by hydroxyl radical footprinting.</a> mAbs. 5 (1), 86-101 (2013).</li><li>Jones, L. M., 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=Complementary+MS+methods+assist+conformational+characterization+of+antibodies+with+altered+S-S+bonding+networks.">Complementary MS methods assist conformational characterization of antibodies with altered S-S bonding networks.</a> Journal of American Society of Mass Spectrometry. 24 (6), 835-845 (2013).</li><li>Storek, K. M., 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=Monoclonal+antibody+targeting+the+&#946;-barrel+assembly+machine+of+Escherichia+coli+is+bactericidal.">Monoclonal antibody targeting the &#946;-barrel assembly machine of Escherichia coli is bactericidal.</a> Proceedings of the National Academy of Sciences. , (2018).</li><li>Vij, R., 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=A+targeted+boost-and-sort+immunization+strategy+using+Escherichia+coli+BamA+identifies+rare+growth+inhibitory+antibodies.">A targeted boost-and-sort immunization strategy using Escherichia coli BamA identifies rare growth inhibitory antibodies.</a> Scientific Reports. 8 (1), 7136 (2018).</li><li>Liu, X. R., Zhang, M. M., Rempel, D. L., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Single+Approach+Reveals+the+Composite+Conformational+Changes,+Order+of+Binding,+and+Affinities+for+Calcium+Binding+to+Calmodulin.">A Single Approach Reveals the Composite Conformational Changes, Order of Binding, and Affinities for Calcium Binding to Calmodulin.</a> Analytical Chemistry. 91 (9), 5508-5512 (2019).</li><li>Lu, Y., 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=Fast+Photochemical+Oxidation+of+Proteins+Maps+the+Topology+of+Intrinsic+Membrane+Proteins:+Light-Harvesting+Complex+2+in+a+Nanodisc.">Fast Photochemical Oxidation of Proteins Maps the Topology of Intrinsic Membrane Proteins: Light-Harvesting Complex 2 in a Nanodisc.</a> Analytical Chemistry. 88 (17), 8827-8834 (2016).</li><li>Marty, M., Zhang, H., Cui, W., Gross, M., Sligar, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Interpretation+and+Deconvolution+of+Nanodisc+Native+Mass+Spectra.">Interpretation and Deconvolution of Nanodisc Native Mass Spectra.</a> Journal of American Society of Mass Spectrometry. 25, (2013).</li><li>Johnson, D. T., Di Stefano, L. H., Jones, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+photochemical+oxidation+of+proteins(FPOP):+A+powerful+mass+spectrometry+based+structural+proteomics+tool.">Fast photochemical oxidation of proteins(FPOP): A powerful mass spectrometry based structural proteomics tool.</a> Journal of Biological Chemistry. , (2019).</li><li>Chea, E. E., Jones, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analyzing+the+structure+of+macromolecules+in+their+native+cellular+environment+using+hydroxyl+radical+footprinting.">Analyzing the structure of macromolecules in their native cellular environment using hydroxyl radical footprinting.</a> Analyst. 143 (4), 798-807 (2018).</li><li>Aprahamian, M. L., Chea, E. E., Jones, L. M., Lindert, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Rosetta+Protein+Structure+Prediction+from+Hydroxyl+Radical+Protein+Footprinting+Mass+Spectrometry+Data.">Rosetta Protein Structure Prediction from Hydroxyl Radical Protein Footprinting Mass Spectrometry Data.</a> Analytical chemistry. 90 (12), 7721-7729 (2018).</li><li>Linde. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Linde Specialty Gases of North America. , (2009).</li><li>Aye, T. T., Low, T. Y., Sze, S. K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanosecond+laser-induced+photochemical+oxidation+method+for+protein+surface+mapping+with+mass+spectrometry.">Nanosecond laser-induced photochemical oxidation method for protein surface mapping with mass spectrometry.</a> Analytical Chemistry. 77 (18), 5814-5822 (2005).</li><li>Niu, B., Zhang, H., Giblin, D., Rempel, D. L., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Dosimetry+determines+the+initial+OH+radical+concentration+in+fast+photochemical+oxidation+of+proteins+(FPOP).">Dosimetry determines the initial OH radical concentration in fast photochemical oxidation of proteins (FPOP).</a> Journal of American Society of Mass Spectrometry. 26 (5), 843-846 (2015).</li><li>Misra, S. K., Orlando, R., Weinberger, S. R., Sharp, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Compensated+Hydroxyl+Radical+Protein+Footprinting+Measures+Buffer+and+Excipient+Effects+on+Conformation+and+Aggregation+in+an+Adalimumab+Biosimilar.">Compensated Hydroxyl Radical Protein Footprinting Measures Buffer and Excipient Effects on Conformation and Aggregation in an Adalimumab Biosimilar.</a> American Association of Pharmaceutical Scientists Journal. 21 (5), 87 (2019).</li><li>Olson, L. J., Misra, S. K., Ishihara, M., Battaile, K. P., Grant, O. C., Sood, A., Woods, R. J., Kim, J. P., Tiemeyer, M., Ren, G., Sharp, J. S., Dahms, N. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Allosteric+regulation+of+lysosomal+enzyme+recognition+by+the+cation-independent+mannose+6-phosphate+receptor.">Allosteric regulation of lysosomal enzyme recognition by the cation-independent mannose 6-phosphate receptor.</a> Communications Biology. 3 (1), 498 (2020).</li><li>Sharp, J. S., Misra, S. K., Persoff, J. J., Egan, R. W., Weinberger, S. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Real+Time+Normalization+of+Fast+Photochemical+Oxidation+of+Proteins+Experiments+by+Inline+Adenine+Radical+Dosimetry.">Real Time Normalization of Fast Photochemical Oxidation of Proteins Experiments by Inline Adenine Radical Dosimetry.</a> Analytical Chemistry. 90 (21), 12625-12630 (2018).</li><li>Misra, S. K., Sharp, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enabling+Real-Time+Compensation+in+Fast+Photochemical+Oxidations+of+Proteins+for+the+Determination+of+Protein+Topography+Changes.">Enabling Real-Time Compensation in Fast Photochemical Oxidations of Proteins for the Determination of Protein Topography Changes.</a> Journal of Visualized Experiments. 163, (2020).</li><li>Hambly, D. M., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Laser+flash+photolysis+of+hydrogen+peroxide+to+oxidize+protein+solvent-accessible+residues+on+the+microsecond+timescale.">Laser flash photolysis of hydrogen peroxide to oxidize protein solvent-accessible residues on the microsecond timescale.</a> Journal of American Society of Mass Spectrometry. 16 (12), 2057-2063 (2005).</li><li>Liu, X. R., Zhang, M. M., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+Spectrometry-Based+Protein+Footprinting+for+Higher-Order+Structure+Analysis:+Fundamentals+and+Applications.">Mass Spectrometry-Based Protein Footprinting for Higher-Order Structure Analysis: Fundamentals and Applications.</a> Chemical Reviews. 120 (10), 4355 (2020).</li><li>Jones, L. M., Sperry, B. J., Carroll, A. J., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fast+photochemical+oxidation+of+proteins+for+epitope+mapping.">Fast photochemical oxidation of proteins for epitope mapping.</a> Analytical chemistry. 83 (20), 7657-7661 (2011).</li><li>Li, J., 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=Mapping+the+Energetic+Epitope+of+an+Antibody/Interleukin-23+Interaction+with+Hydrogen/Deuterium+Exchange,+Fast+Photochemical+Oxidation+of+Proteins+Mass+Spectrometry,+and+Alanine+Shave+Mutagenesis.">Mapping the Energetic Epitope of an Antibody/Interleukin-23 Interaction with Hydrogen/Deuterium Exchange, Fast Photochemical Oxidation of Proteins Mass Spectrometry, and Alanine Shave Mutagenesis.</a> Analytical chemistry. 89 (4), 2250-2258 (2017).</li><li>Liu, X. R., Zhang, M. M., Rempel, D. L., Gross, M. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Single+Approach+Reveals+the+Composite+Conformational+Changes,+Order+of+Binding,+and+Affinities+for+Calcium+Binding+to+Calmodulin.">A Single Approach Reveals the Composite Conformational Changes, Order of Binding, and Affinities for Calcium Binding to Calmodulin.</a> Analytical Chemistry. 91 (9), 5508-5512 (2019).</li><li>Kiselar, J. G., Janmey, P. A., Almo, S. C., Chance, M. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Structural+analysis+of+gelsolin+using+synchrotron+protein+footprinting.">Structural analysis of gelsolin using synchrotron protein footprinting.</a> Molecular and Cellular Proteomics. 2 (10), 1120-1132 (2003).</li><li>Chea, E. E., Deredge, D. J., Jones, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Insights+on+the+Conformational+Ensemble+of+Cyt+C+Reveal+a+Compact+State+during+Peroxidase+Activity.">Insights on the Conformational Ensemble of Cyt C Reveal a Compact State during Peroxidase Activity.</a> Biophysical Journal. 118 (1), 128-137 (2020).</li><li>Poor, T. A., 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=Probing+the+paramyxovirus+fusion+(F)+protein-refolding+event+from+pre-+to+postfusion+by+oxidative+footprinting.">Probing the paramyxovirus fusion (F) protein-refolding event from pre- to postfusion by oxidative footprinting.</a> Proceedings of the National Academy of Sciences U S A. 111 (25), 2596-2605 (2014).</li><li>Roush, A. E., Riaz, M., Misra, S. K., Weinberger, S. R., Sharp, J. S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Intrinsic+Buffer+Hydroxyl+Radical+Dosimetry+Using+Tris(hydroxymethyl)aminomethane.">Intrinsic Buffer Hydroxyl Radical Dosimetry Using Tris(hydroxymethyl)aminomethane.</a> Journal of American Society of Mass Spectrometry. 31 (2), 169-172 (2020).</li><li>Everett, E. A., Falick, A. M., Reich, N. O. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+a+critical+cysteine+in+EcoRI+DNA+methyltransferase+by+mass+spectrometry.">Identification of a critical cysteine in EcoRI DNA methyltransferase by mass spectrometry.</a> Journal of Biological Chemistry. 265 (29), 17713-17719 (1990).</li><li>Sanderson, R. J., Mosbaugh, D. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Identification+of+specific+carboxyl+groups+on+uracil-DNA+glycosylase+inhibitor+protein+that+are+required+for+activity.">Identification of specific carboxyl groups on uracil-DNA glycosylase inhibitor protein that are required for activity.</a> Journal of Biological Chemistry. 271 (46), 29170-29181 (1996).</li></ol>

There are several critical steps to ensure proper labeling of proteins during any HRPF experiment. First, an appropriate flow rate and source flash rate are selected to make certain each bolus of the sample is irradiated once. This ensures that the protein is exposed to a single bolus of newly formed &#9642;OH. Once a protein is oxidized, the higher order protein structure can be altered. To be confident the native protein structure is probed, each protein molecule must be modified in a single instant. Dosimet...

Protein conformation and associated higher order structure (HOS) are the principal determinants of proper biological function and aberrant behavior1. The same applies to biopharmaceuticals, whose structure and functional activity is dependent on various aspects of their production and environment. Biopharmaceutical change in HOS have been linked to adverse drug reactions (ADR) attributed to undesirable pharmacology and patient immunological response2,3. The appearance of ADRs has alerted the biopharmaceutical industry to the critical role that protein HOS plays in the safety and efficacy of biotherapeutics, and they have established the need for new and improved HOS analytics4.
Hydroxyl Radical Protein Footprinting (HRPF) is a promising technique to track the change in protein HOS. HRPF involves the irreversible labeling of a protein&#8217;s exterior with &#9642;OH followed with mass spectrometry (MS) analysis to identify the solvent accessible surface of the protein5,6,7. HRPF has successfully been used to detect defects in protein HOS and its function8,9, characterize the HOS of monoclonal antibodies (mAb)10,11,12,13, determine the binding Kd of a ligand14, and much more15,16,17,18,19. A common method to generate the &#9642;OH for HRPF is Fast Photochemical Oxidation of Proteins (FPOP), which employs high-energy, fast UV lasers to produce &#9642;OH from photolysis of H2O2. For the most part, FPOP uses expensive excimer lasers employing hazardous gas (KrF) that demands substantial safeguards to avoid respiratory and eye injury20. To avoid inhalation hazards, others have used frequency quadrupled neodymium yttrium aluminum garnet (Nd:YAG) lasers21, which eliminates the use of toxic gas but are still costly, require significant operational expertise, and demand extensive stray light controls to protect users from eye injury.
Although ample information can be obtained using HRPF, broad adoption in biopharma has not been met. Two barriers for the limited HRPF adoption include: 1) the use of dangerous and expensive lasers that demand substantial safety precautions20; and 2) the irreproducibility of HRPF caused by background scavenging of &#9642;OH that limit comparative studies22. To supplant laser use, a high-speed, high energy plasma flash photolysis unit was developed to safely perform FPOP in a facile manner. To improve on the irreproducibility of HRPF experiments, real-time radical dosimetry is implemented.
The practice of HRPF has been limited by irreproducibility attributed to background scavenging of &#9642;OH22. While &#9642;OH are excellent probes of protein topography, they also react with many constituents found in preparations, making it necessary to measure the effective concentration of radical available to oxidize a target protein. Variations in buffer preparation, hydrogen peroxide concentration, ligand properties, or photolysis can result in oxidation differences between control and experimental groups that create ambiguity in HOS differential studies. The addition of real-time radical dosimetry enables the adjustment of the effect &#9642;OH load and therefore increases the confidence and reproducibility during an HRPF experiment. The use of radical dosimetry in FPOP has been described elsewhere23,24,25, and is further discussed in detail in a recent publication26. Here, we describe the use of a novel flash photolysis system and real-time dosimetry to label equine apo-myoglobin (aMb), comparing levels of peptide oxidation in an FPOP experiment to that of obtained when using an excimer laser.

<table>
	<tbody>
		<tr>
			<td>15 mL Conical Centrifuge Tubes</td>
			<td>Fisher Scientific</td>
			<td>14-959-53A</td>
			<td>any brand is sufficient</td>
		</tr>
		<tr>
			<td>50 &#181;L SGE Gastight Syringes</td>
			<td>Fisher Scientific</td>
			<td>SG-00723</td>
			<td></td>
		</tr>
		<tr>
			<td>Acclaim PepMap 100 C18 nanocolumn (0.75 mm X 150 mm, 2 &#181;m)</td>
			<td>Thermo Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Acetonitrile with 0.1% Formic Acid (v/v), LC/MS Grade</td>
			<td>Fisher Scientific</td>
			<td>LS120-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Apomyoglobin</td>
			<td>Sigma-Aldrich</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Catalase</td>
			<td>Sigma-Aldrich</td>
			<td>C9322</td>
			<td></td>
		</tr>
		<tr>
			<td>Centrifuge</td>
			<td>Eppendorf</td>
			<td>022625501</td>
			<td></td>
		</tr>
		<tr>
			<td>Delicate Task Wipers</td>
			<td>Fisher Scientific</td>
			<td>06-666A</td>
			<td></td>
		</tr>
		<tr>
			<td>Hydrogen Peroxide</td>
			<td>Fisher Scientific</td>
			<td>H325-100</td>
			<td>any 30% hydrogen peroxide is sufficient</td>
		</tr>
		<tr>
			<td>Methionine amide</td>
			<td>Chem-Impex</td>
			<td>03109</td>
			<td></td>
		</tr>
		<tr>
			<td>Microcentrifuge</td>
			<td>Thermo Scientific</td>
			<td>75002436</td>
			<td></td>
		</tr>
		<tr>
			<td>Orbitrap Fusion Lumos Tribrid Mass Spectrometer</td>
			<td>Thermo Scientific</td>
			<td>Orbitrap Fusion Lumos Tribrid Mass Spectrometer</td>
			<td>other high resolution instruments (e.g. Q exactive Orbitrap or Orbitrap Fusion) can be used</td>
		</tr>
		<tr>
			<td>Pierce Trypsin Protease, MS Grade</td>
			<td>Thermo Scientific</td>
			<td>90058</td>
			<td></td>
		</tr>
		<tr>
			<td>Polymicro Cleaving Stone, 1&#34; x 1&#34; x 1/32&#8221;</td>
			<td>Molex</td>
			<td>1068680064</td>
			<td>any capillary tubing cutter is sufficient</td>
		</tr>
		<tr>
			<td>UPLC</td>
			<td>Thermo Scientific</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Water with 0.1% Formic Acid (v/v), LC/MS Grade</td>
			<td>Fisher Scientific</td>
			<td>LS118-500</td>
			<td></td>
		</tr>
		<tr>
			<td>Water, LC/MS Grade</td>
			<td>Fisher Scientific</td>
			<td>W6-4</td>
			<td></td>
		</tr>
	</tbody>
</table>

laser-free hydroxyl radical protein footprinting to perform higher order structural analysis of proteins

Hydroxyl Radical Protein Footprinting (HRPF) is an emerging and promising higher order structural analysis technique that provides information on changes in protein structure, protein-protein interactions, or protein-ligand interactions. HRPF utilizes hydroxyl radicals (&#9642;OH) to irreversibly label a protein&#8217;s solvent accessible surface. The inherent complexity, cost, and hazardous nature of performing HRPF have substantially limited broad-based adoption in biopharma. These factors include: 1) the use of complicated, dangerous, and expensive lasers that demand substantial safety precautions; and 2) the irreproducibility of HRPF caused by background scavenging of &#9642;OH that limit comparative studies. This publication provides a protocol for operation of a laser-free HRPF system. This laser-free HRPF system utilizes a high energy, high-pressure plasma light source flash oxidation technology with in-line radical dosimetry. The plasma light source is safer, easier to use, and more efficient in generating hydroxyl radicals than laser-based HRPF systems, and the in-line radical dosimeter increases the reproducibility of studies. Combined, the laser-free HRPF system addresses and surmounts the mentioned shortcomings and limitations of laser-based techniques.

The high-pressure plasma source coupled with real-time dosimetry allows better control of &#9642;OH yield to observe changes in higher-order protein structure more accurately. The addition of adenine allows for an effective real-time radical dosimeter. Upon oxidation, adenine loses UV absorbance at 265 nm (Figure 2A). The change in adenine absorbance is directly related to the concentration of radicals available for HRPF thus providing a means to effectively monitor changes in rad...

Watch this Scientific Journal Video about Laser-free Hydroxyl Radical Protein Footprinting to Perform Higher Order Structural Analysis of Proteins at JoVE.com

Laser-free Hydroxyl Radical Protein Footprinting to Perform Higher Order Structural Analysis of Proteins

This protocol presents a method to use inline radical dosimetry and a plasma light source to perform flash oxidation protein footprinting. This method replaces the hazardous UV laser to simplify and improve the reproducibility of fast photochemical oxidation of protein studies.

Hydroxyl Radical Protein Footprinting (HRPF) is an emerging and promising higher order structural analysis technique that provides information on changes ...

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Unit 1

Protein Structure

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