关闭

关闭

关闭

封号提示

内容

首页 蛋白质结晶之Tips X 氙气.doc

蛋白质结晶之Tips X 氙气.doc

蛋白质结晶之Tips X 氙气.doc

上传者: eva爽 2017-11-17 评分 0 0 0 0 0 0 暂无简介 简介 举报

简介:本文档为《蛋白质结晶之Tips X 氙气doc》,可适用于自然科学领域,主题内容包含蛋白质结晶之TipsX氙气X代表氙气(Xenon)氙气可以结合到生物大分子特定的位点。氙气与蛋白形成的复合物可以用来做同型置换。蛋白晶体与氙气在高压符等。

蛋白质结晶之TipsX氙气X代表氙气(Xenon)氙气可以结合到生物大分子特定的位点。氙气与蛋白形成的复合物可以用来做同型置换。蛋白晶体与氙气在高压下反应即可得到蛋白晶体的重原子衍生物。大多数情况下由于晶体和母液在一个充满氙气的盒子中所以不用调节母液来选择浸泡的条件。使用氙气的另外一个优势是氙气与蛋白的结合较弱所以不会太多影响蛋白的结构。通过调节气压还能改变氙气与蛋白结合的数量及位点所以当常规的浸泡重原子的方法失败以后可以尝试用氙气。氙气与蛋白的结合是可逆的所以当晶体的量很少时用过的晶体还能再泡重原子。氙气与蛋白之间的相互作用比较弱不涉及静电相互作用。所以相比较重原子而言氙气可以结合到蛋白上很多位点。并且由于氙气与蛋白相互作用较弱它不太可能改变蛋白晶体中蛋白分子与蛋白分子之间的结合方式。用氙气得到的衍生物与蛋白晶体真实构象没有多大差别。氙气对母液的pH和离子强度没有明显影响。由于氙气与蛋白相互作用较弱所以在泡制时需要高压以保证氙气充分结合到蛋白上各个可能结合的位点。此时冷却处理就不会改变蛋白与氙气的结合了。利用氙气得到晶体衍生物的实验可以在常温下操作数据收集也可以在特殊的装置中进行。氙气的另外一个用途是可以用来做膜蛋白结构上不规则区域的成像。原文:XenonisanoblegasthatbindstospecificsitesinamacromoleculeXenonproteincomplexescanoftenserveasheavyatomcomplexesforMIRstructuredeterminationHeavyatomderivativesofproteincrystalscanbeproducedbypressurizingnativecrystalswithxenongasInthevastmajorityofcases,themodificationofthemotherliquortodeterminesoakingconditionsisavoidedsincethecrystalandmotherliquoraresimplyplacedinachamberpressurizedwithxenongasAnotheradvantageofworkingwithxenonisthatitinteractsweaklywithaproteinsoisomorphismofthederivativewiththenativecrystalishighAlso,thenumberofbindingsitesaswellasthebindingoccupanciescanoftenbechangedbyalteringthepressureofthexenongasXenonbindingsitesoftendifferfromheavymetalbindingsitessoitcanbeusefultotryxenonwhentraditionalheavyatomsoaksfailXenonbindingisoftenreversiblesoifonehasveryfewcrystals,thesamecrystalcouldbeusedforheavyatomsoakTheinteractionbetweenxenonandtheproteinistypicallyconfinedtoweakdispersionforcesanddoesnotinvolveelectrostaticinteractionsTherefore,xenonshouldbindtodifferentlocationsoftheproteincomparedtomostotherheavyatomcompoundsTheweaknessoftheinteractionbetweenxenonandtheproteinmakesitunlikelythatxenonwillinterferewithcrystalcontactsXenonderivativesusuallyshowgoodisomorphicitywiththenativecrystal,resultinginhighphasingpowerXenonseemstohavelittleornoeffectonthepHorionicstrengthofthemotherliquorTheweaknessoftheinteractionsbetweenxenonandproteinsrequiresasignificantxenonconcentrationinthecrystal’smotherliquortoenforcesufficientoccupationofapotentialbindingsitesomostusesofxenonreportedintheliteraturemakeuseofhighpressureequipmentforxenonderivatizationAtthistimeisappearscryocoolingdoesnotaltertheprotein’sxenonbindingpropertiesXenonderivatizationcanbeperformedatroomtemperatureanddatacollectionwithxenonderivativescanbeperformedatroomtemperatureusingspeciallymadepressurecellsandcapillariesoratcryogenictemperaturesusingCryoLoopsAnotherapplicationofxenoninproteincrystalsisthecrystallographicimagingofdisorderedareasoflipidsordetergentsincrystalsofmembraneproteinsReferencesforusingxenonasaderivative:BindingofXenontoSpermWhaleMyoglobinSchoenbornBPWatson,HCKendrew,JC()Nature,,Cavitiesinproteins:structureofametmyoglobinxenoncomplexsolvedtoAngringTilton,RFKuntz,LDPesko,GA()BiochemistryUsingXenonasaHeavyAtomforDeterminingPhasesinSpermWhaleMetmyoglobinVitali,JRobbins,AHAlmo,SCTilton,RF()JournalofAppliedCrystallography,,OnthePreparationandXrayDataCollectionofIsomorphousXenonDerivativesSchiltz,MPrange,TFourme,R()JournalofAppliedCrystallography,,SuccessfulflashcoolingofxenonderivatisedmyoglobincrystalsSoltis,SMStowell,MHBWiener,MCPhilips,GNRees,DC()JournalofAppliedCrystallography,,FreezeTrappingIsomorphousXenonDerivativesofProteinCrystalsSauer,OSchmidt,AKratky,C()JournalofAppliedCrystallography,,ProteinCrystallographyatUltraShortWavelengths:FeasibilityStudyofAnomalousDispersionExperimentsattheXenonKEdgeSchiltz,M,Kvick,A,Svensson,O,Shepard,W,DeLaFortelle,E,Prange,T,Kahn,RFourme,R()JournalofSynchrotronRadiation,,AmethodtostabilizereducedandorgastreatedproteincrystalsbyflashcoolingunderacontrolledatmospherXavierVermedeetalJAppCryst,()()Betterstructuresfrombetterdatathroughbettermethods:areviewofdevelopmentsindenovomacromolecularphasingtechniquesandassociatedinstrumentationatLUREFourme,Retal()JSynchRad()Timmins,P,PebayPeroula,EWelte,W()BiophysChem,

用户评论(0)

0/200

精彩专题

上传我的资料

每篇奖励 +2积分

资料评价:

/5
0下载券 下载 加入VIP, 送下载券

意见
反馈

立即扫码关注

爱问共享资料微信公众号

返回
顶部