Name: visualizing the interaction between the qdot-labeled protein and site-specifically modified &#955; dna at the single molecule level
Uploaded: 2018-07-17T14:30:00
Description: Watch this Scientific Journal Video about Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified ÃŽÂ» DNA at the Single Molecule Level at JoVE.com

Vi takker Dr. Hasan Yardimci og Dr.Sevim Yardimci av Francis Crick Institute for type i enkelt-molekylet eksperimentene, Dr. Daniel Duzdevich fra Dr. Eric C. Greenes lab ved Columbia University, Dr. Yujie Sun Peking University og Dr. Chunlai Chen hos Tsinghuauniversitetet for nyttig diskusjon. Denne studien ble støttet av National Natural Science Foundation of China 31371264, 31401059, CAS tverrfaglig innovasjon Team og Newton avansert brorskapet (NA140085) fra Royal Society.

1. forberedelse av λ-ARS317 DNA substrat
<ol><li>DNA substrat bygg og emballasje<ol>
<li>Fordøye innfødt λ DNA ved å bruke Xhojeg enzym; forsterke 543 bp DNA fragment betydning ARS317 fra genomisk DNA av spirende gjær bruker primer som inneholder 20 bp homologe sekvenser av oppstrøms og nedstrøms Xhojeg enzym område på lambda DNA. Legg 100 ng av Xhojeg fordøyd λ DNA og 10 ng DNA fragment til 10 µL av homologe rekombinasjon reaksjonssystemet og ruge reaksjonen på 37 ° C i 30 min...

<ol>
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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=Real-time+single-molecule+imaging+reveals+a+direct+interaction+between+UvrC+and+UvrB+on+DNA+tightropes.">Real-time single-molecule imaging reveals a direct interaction between UvrC and UvrB on DNA tightropes.</a> Nucleic acids research. 41 (9), 4901-4912 (2013).</li><li>Kad, N. M., Wang, H., Kennedy, G. G., Warshaw, D. M., Van Houten, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Collaborative+dynamic+DNA+scanning+by+nucleotide+excision+repair+proteins+investigated+by+single-molecule+imaging+of+quantum-dot-labeled+proteins.">Collaborative dynamic DNA scanning by nucleotide excision repair proteins investigated by single-molecule imaging of quantum-dot-labeled proteins.</a> Molecular cell. 37 (5), 702-713 (2010).</li><li>Chandradoss, S. 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=Surface+Passivation+for+Single-molecule+Protein+Studies.">Surface Passivation for Single-molecule Protein Studies.</a> Jove-Journal of Visualized Experiments. (86), (2014).</li><li>Chen, X. Q., Zhao, E. S., Fu, Y. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Using+single-molecule+approach+to+visualize+the+nucleosome+assembly+in+yeast+nucleoplasmic+extracts.">Using single-molecule approach to visualize the nucleosome assembly in yeast nucleoplasmic extracts.</a> Science Bulletin. 62 (6), 399-404 (2017).</li><li>Yardimci, H., Loveland, A. B., van Oijen, A. M., Walter, J. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-molecule+analysis+of+DNA+replication+in+Xenopus+egg+extracts.">Single-molecule analysis of DNA replication in Xenopus egg extracts.</a> Methods. 57 (2), 179-186 (2012).</li><li>Tanner, N. A., Loparo, J. J., van Oijen, A. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Visualizing+single-molecule+DNA+replication+with+fluorescence+microscopy.">Visualizing single-molecule DNA replication with fluorescence microscopy.</a> Journal of visualized experiments: JoVE. (32), (2009).</li><li>Lockett, T. 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Her presenterer vi en protokoll for å observere samspillet mellom Qdot-merket protein og site-specifically endret λ DNA ved hjelp av TIRFM i en flyt-celle. Fremgangsmåten er områdespesifikke endring av DNA substrat, DNA biotinylation, dekkglassvæske rengjøring og functionalization, flyt-celle forberedelse og enkelt-molekylet bildebehandling. Det er to viktige punkter som bør bemerkes. Først alle trinnene involvert med λ DNA skal manipuleres forsiktig for å redusere mulig skade, f.eksunngå blanding av ...

Samspillet mellom protein og DNA er avgjørende for mange komplekse biologiske prosesser, som utryddelse, DNA-reparasjon og transkripsjon. Selv om konvensjonelle metoder har kaste lys over egenskapene til disse prosessene, er mange viktige mekanismer fortsatt uklart. Nylig, med rask utvikling enkelt molekyl teknikker, noen de har vært adressert1,2,3.
Anvendelsen av enkelt-molekylet fluorescens mikroskopi på å synliggjøre protein-DNA interaksjoner i sanntid hovedsakelig avhenger av utviklingen av fluorescens gjenkjenning og fluorescerende sonder. For en enkelt molekyl studie er det viktig å merke protein rundt med en egnet fluorescerende sonde siden fluorescens oppdagingssystemer er mest tilgjengelig kommersielt.
Fluorescerende proteiner brukes ofte i molekylærbiologi. Imidlertid begrenser lite lysstoffrør lysstyrken og stabilitet mot photobleaching anvendelsen i mange ett molekyl analyser. Kvante prikker (Qdots) er små lys-emitting nanopartikler4. Deres unike optiske egenskaper, Qdots er 10 - 20 ganger lysere og flere tusen ganger mer stabilt enn de brukte organisk fargestoffer5. Videre har Qdots en stor Stokes Skift (forskjellen mellom plasseringen av eksitasjon og utslipp topper)5. Qdots kan dermed brukes til mangeårige observasjon (minutter timer) og anskaffelse av bilder med høy signal-til-støy-forhold, mens de ikke kan brukes i kvantitative analyser.
Dato det er to tilnærminger til å merke et mål protein med Qdots site-specifically: merking ved hjelp av Qdot-konjugerte primær eller sekundær antistoffer6,7,8; eller merking målet protein med Qdots direkte, som er basert på den sterke vekselvirkningen mellom biotin og streptavidin9,10,11,12,13. Streptavidin-belagt Qdots er kommersielt tilgjengelig. I vår siste undersøkelse, site-specifically biotinylated proteiner i spirende gjær med høy effektivitet renset ved co-overuttrykte BirA og Avi-merket proteiner i vivo10. Følgende og optimalisere de single-molekyl analyser14,15,16,17, observerte vi samspillet mellom Qdot-merket proteiner og DNA på ett molekyl nivå ved TIRFM10.
Her, vi velger spirende gjær opprinnelse-anerkjennelse komplekse (ORC), som kan spesielt gjenkjenner og binder til selvstendig etterligner sekvensen (ARS), som vår protein av interesse. Følgende protokollen presenterer en fremgangsmåte å visualisere samspillet av Qdot-merket ORC Ars bruker TIRFM. Utarbeidelse av site-specifically endret DNA underlaget, DNA-biotinylation, dekkglassvæske rengjøring og functionalization, samlingen flyt-celle og enkelt-molekylet avbilding er beskrevet.

<table>
	<tbody>
		<tr>
			<td>Lambda DNA</td>
			<td>New England Biolabs</td>
			<td>N3011</td>
			<td>Store 25 &#956;L aliquots at -20 &#186;C.</td>
		</tr>
		<tr>
			<td>XhoI enzyme</td>
			<td>Thermo Fisher Scientific</td>
			<td>FD0694</td>
			<td></td>
		</tr>
		<tr>
			<td>Quick-fusion cloning kit</td>
			<td>Biotool</td>
			<td>B22611</td>
			<td></td>
		</tr>
		<tr>
			<td>MaxPlax Lambda 
			Packaging Extracts</td>
			<td>Epicentre</td>
			<td>MP5110</td>
			<td>Bacterial strain LE392MP 
			is included in this package.</td>
		</tr>
		<tr>
			<td>MgSO4</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10013092</td>
			<td>Any brand is acceptable.</td>
		</tr>
		<tr>
			<td>Tris</td>
			<td>Amresco</td>
			<td>0497-5KG</td>
			<td></td>
		</tr>
		<tr>
			<td>NaCl</td>
			<td>Beijing Chemical works</td>
			<td>N/A</td>
			<td>Any brand is acceptable.</td>
		</tr>
		<tr>
			<td>MgCl2</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10012818</td>
			<td></td>
		</tr>
		<tr>
			<td>Chloroform</td>
			<td>Beijing Chemical works</td>
			<td>N/A</td>
			<td>Any brand is acceptable.</td>
		</tr>
		<tr>
			<td>NZ-amine</td>
			<td>Amresco</td>
			<td>J853-250G</td>
			<td></td>
		</tr>
		<tr>
			<td>Casamino acids</td>
			<td>Sigma-Aldrich</td>
			<td>22090-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>PEG8000</td>
			<td>Beyotime</td>
			<td>ST483</td>
			<td></td>
		</tr>
		<tr>
			<td>Magnetic stirring apparatus</td>
			<td>IKA</td>
			<td>KMO2 basic</td>
			<td></td>
		</tr>
		<tr>
			<td>15 mL Eppendorf tube</td>
			<td>Eppendorf</td>
			<td>30122151</td>
			<td>15 mL, sterile, bulk, 500pcs</td>
		</tr>
		<tr>
			<td>Rnase</td>
			<td>SIGMA</td>
			<td>R4875-100MG</td>
			<td></td>
		</tr>
		<tr>
			<td>Dnase</td>
			<td>SIGMA</td>
			<td>D5319-500UG</td>
			<td></td>
		</tr>
		<tr>
			<td>Proteinase K</td>
			<td>Amresco</td>
			<td>0706-100MG</td>
			<td></td>
		</tr>
		<tr>
			<td>Biotinylated primers</td>
			<td>Thermo Fisher Scientific</td>
			<td>N/A</td>
			<td></td>
		</tr>
		<tr>
			<td>T4 DNA ligase, T4 DNA Ligase, Reaction Buffer (10x)</td>
			<td>New England Biolabs</td>
			<td>M0202</td>
			<td></td>
		</tr>
		<tr>
			<td>Coverslip</td>
			<td>Thermo Fisher Scientific</td>
			<td>22266882</td>
			<td></td>
		</tr>
		<tr>
			<td>Ethanol</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10009259</td>
			<td></td>
		</tr>
		<tr>
			<td>Potassium hydroxide (KOH)</td>
			<td>Sigma-Aldrich</td>
			<td>306568-100G</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetone</td>
			<td>Thermo Fisher Scientific</td>
			<td>A949-4</td>
			<td></td>
		</tr>
		<tr>
			<td>H2SO4</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>80120891</td>
			<td>sulfuric acid</td>
		</tr>
		<tr>
			<td>H2O2</td>
			<td>Sinopharm Chemical Reagent Co.,Ltd</td>
			<td>10011218</td>
			<td>30% Hydrogen peroxide</td>
		</tr>
		<tr>
			<td>Methanol</td>
			<td>Sigma-Aldrich</td>
			<td>322415-2L</td>
			<td></td>
		</tr>
		<tr>
			<td>Acetic acid</td>
			<td>Sigma-Aldrich</td>
			<td>V900798</td>
			<td></td>
		</tr>
		<tr>
			<td>APTES</td>
			<td>Sigma-Aldrich</td>
			<td>A3648</td>
			<td></td>
		</tr>
		<tr>
			<td>mPEG 
			(methoxy-polyethylene glycol)</td>
			<td>Lysan</td>
			<td>mPEG-SVA-5000</td>
			<td></td>
		</tr>
		<tr>
			<td>biotin-PEG 
			(biotin-polyethylene glycol)</td>
			<td>Lysan</td>
			<td>Biotin-PEG-SVA-5000</td>
			<td></td>
		</tr>
		<tr>
			<td>NaHCO3</td>
			<td>Sigma-Aldrich</td>
			<td>31437-500G</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum desiccator</td>
			<td>Tianjin Branch Billion Lung Experimental Equipment Co., Ltd.</td>
			<td>IPC250-1</td>
			<td></td>
		</tr>
		<tr>
			<td>Vacuum sealer</td>
			<td>MAGIC SEAL</td>
			<td>WP300</td>
			<td></td>
		</tr>
		<tr>
			<td>Diamond-tipped glass scribe</td>
			<td>ELECTRON MICROSCOPY SCIENCES</td>
			<td>70036</td>
			<td></td>
		</tr>
		<tr>
			<td>Glass slide</td>
			<td>Sail Brand</td>
			<td>7101</td>
			<td></td>
		</tr>
		<tr>
			<td>Inlet tubing</td>
			<td>SCI (Scientific Commodties INC.)</td>
			<td>BB31695-PE/2</td>
			<td>inner diameter 0.38 mm; outer diameter 1.09 mm.</td>
		</tr>
		<tr>
			<td>Outlet tubing</td>
			<td>SCI (Scientific Commodties INC.)</td>
			<td>BB31695-PE/4</td>
			<td>inner diameter 0.76 mm; outer diameter 1.22 mm.</td>
		</tr>
		<tr>
			<td>Double-sided tape</td>
			<td>Sigma-Aldrich</td>
			<td>GBL620001-1EA</td>
			<td></td>
		</tr>
		<tr>
			<td>Epoxy</td>
			<td>LEAFTOP</td>
			<td>9005</td>
			<td>five minutes epoxy</td>
		</tr>
		<tr>
			<td>Streptavidin</td>
			<td>Sigma-Aldrich</td>
			<td>S4762</td>
			<td></td>
		</tr>
		<tr>
			<td>Fluorescence Microscope</td>
			<td>Olympus</td>
			<td>IX71</td>
			<td></td>
		</tr>
		<tr>
			<td>Infusion/withdrawal 
			programmable pump</td>
			<td>Harvard apparatus</td>
			<td>70-4504</td>
			<td></td>
		</tr>
		<tr>
			<td>532 nm laser</td>
			<td>Coherent</td>
			<td>Sapphire-532-50</td>
			<td></td>
		</tr>
		<tr>
			<td>640 nm laser</td>
			<td>Coherent</td>
			<td>OBIS-640-100</td>
			<td></td>
		</tr>
		<tr>
			<td>EMCCD Camera</td>
			<td>Andor</td>
			<td>DU-897E-CS0-BV</td>
			<td></td>
		</tr>
		<tr>
			<td>W-View Gemini Imaging 
			splitting optics</td>
			<td>Hamamatsu photonics K.K.</td>
			<td>A12801-01</td>
			<td></td>
		</tr>
		<tr>
			<td>TIRF illumination system</td>
			<td>Olympus</td>
			<td>IX2-RFAEVA2</td>
			<td></td>
		</tr>
		<tr>
			<td>60&#215;TIRF objective</td>
			<td>Olympus</td>
			<td>APON60XOTIRF</td>
			<td></td>
		</tr>
		<tr>
			<td>Quad-edge laser dichroic 
			beamsplitter</td>
			<td>Semrock</td>
			<td>Di01-R405/488/ 
			532/635-25x36</td>
			<td></td>
		</tr>
		<tr>
			<td>Quad-band bandpass filter</td>
			<td>Semrock</td>
			<td>FF01-446/510/ 
			581/703-25</td>
			<td></td>
		</tr>
		<tr>
			<td>Dichroic beamsplitter</td>
			<td>Semrock</td>
			<td>FF649-Di01-25x36</td>
			<td></td>
		</tr>
		<tr>
			<td>Emission filter</td>
			<td>Chroma Technology Corp</td>
			<td>ET585/65m</td>
			<td></td>
		</tr>
		<tr>
			<td>Emission filter</td>
			<td>Chroma Technology Corp</td>
			<td>ET665lp</td>
			<td></td>
		</tr>
		<tr>
			<td>FocalCheck fluorescence, microscope test slide #1</td>
			<td>Thermo Fisher Scientific</td>
			<td>F36909</td>
			<td></td>
		</tr>
		<tr>
			<td>SYTOX Orange</td>
			<td>Thermo Fisher Scientific</td>
			<td>S11368</td>
			<td></td>
		</tr>
		<tr>
			<td>Qdot705 Streptavidin Conjugate</td>
			<td>Thermo Fisher Scientific</td>
			<td>Q10163MP</td>
			<td>Store at 4 &#186;C, do not freeze.</td>
		</tr>
		<tr>
			<td>ATP</td>
			<td>Amresco</td>
			<td>0220-25G</td>
			<td>Prepare 200 mM ATP solution, using ddH2O, adjust pH to 7.0, and store 10 &#956;L aliquots at -20 &#186;C.</td>
		</tr>
		<tr>
			<td>DTT</td>
			<td>Amresco</td>
			<td>M109-5G</td>
			<td>Prepare 1 M solution using ddH2O, and store 10 &#956;l aliquots at -20 &#186;C.</td>
		</tr>
	</tbody>
</table>

visualizing the interaction between the qdot-labeled protein and site-specifically modified &#955; dna at the single molecule level

Fluorescens mikroskopi har gjort store bidrag i dissekere mekanismer for komplekse biologiske prosesser på ett molekyl nivå. I ett molekyl analyser for å studere DNA-protein interaksjoner, finnes det to viktige faktorer for vurdering: DNA underlaget med nok lang for enkel observasjon og merking et protein med en egnet fluorescerende sonde. 48.5 kb λ DNA er en god kandidat for DNA underlaget. Kvante prikker (Qdots), tillate som en klasse med fluorescerende sonder, mangeårige observasjon (minutter timer) og høy kvalitet bilde. I dette papiret presenterer vi en protokoll for å studere DNA-protein interaksjoner på enkelt-molekylet nivå, som inkluderer forbereder en site-specifically endret λ DNA og merking et mål protein med streptavidin-belagt Qdots. En konseptbeviskode vi velger ORC (opprinnelse gjenkjennelse komplekse) i spirende gjær som et protein av interesse og visualisere dets interaksjon med en ARS (selvstendig etterligner sekvens) ved hjelp av TIRFM. Sammenlignet med andre fluorescerende sonder, Qdots har åpenbare fordeler i ett molekyl studier på grunn av dens høy stabilitet mot photobleaching, men det bør bemerkes at denne egenskapen begrenser anvendelsen i kvantitative analyser.

For å visualisere samspillet mellom Qdot-merket ORC og ARS, bygget vi første λ-ARS317 DNA underlaget. En DNA fragment som inneholder ARS317 ble integrert i Xhojeg området (33,5 kb) native λ DNA av homologe rekombinasjon (figur 1A). Rekombinasjon produktet ble pakket bruker ekstrakter og pakket phage partikler ble kultivert på LB plater (figur 1B). En positiv phage plakett ble vist av PCR og bekreftet av sekvenserin...

Watch this Scientific Journal Video about Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified ÃŽÂ» DNA at the Single Molecule Level at JoVE.com

Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified ÃƒÆ’Ã…Â½Ãƒâ€šÃ‚Â» DNA at the Single Molecule Level

Her presenterer vi en protokoll for å studere DNA-protein interaksjoner av total intern refleksjon fluorescens mikroskopi (TIRFM) bruker en site-specifically endret λ DNA substrat og en kvante-prikk merket protein.

Visualisere samspillet mellom Qdot-merket Protein og Site-specifically endret λ DNA på ett molekyl nivå

The fluorescence microscopy&#160;has made great contributions in dissecting the mechanisms of complex biological processes at the single molecule level. ...

Research

JoVE Journal

Biology

Visualizing the Interaction Between the Qdot-labeled Protein and Site-specifically Modified &#955; DNA at the Single Molecule Level

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Long interspersed nuclear element-1 (Line-1 or L1) accounts for approximately 17% of the DNA present in the human genome. While the majority of L1s are ...

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