简介：TheroleplayedbyDNAinmolecularbiologyisclearlyrecognizedtobevitaltolifeonthisplanet.8-oxo-7,8-dihydro-2deoxyguanosine(=8-OHdG),isprobablythemostimportantproductof"oxidativestress”inDNA.ItsconcentrationinDNAis,infact.aquantitativeanalysisofthedegreeofDNAdamagethatanorganismhasundergone.Duetotheimportanceof8-OHdGofnucleicacidginmutagenesis,carcinogenesisandaging,numerouschemicalandbiologicalinvestigationshavebeenmadeonthissubjectinthepasttime.Kuchinoandco-workershavefoundthat8-OHdGresidueinDNAismisreadingduringtheprocessofDNAreplication.Recently,somereportshavebeenpresentedonhigh8-OHdGlevelsinpatientssufferingfromvariousdiseasessuchaschronichepatitis,Fanconisanemia,diabetesmellitusandHelicobacterpyloriinfections.Asaresult,8-OHdGisausefulmarkerforthestudyofDNAdamagearisingfromreactiveoxygenspeciesandisofgreatsignificanceforcancerresearch.The8-OHdGlevelsinDNAcanhelpunderstandthemechanismofcarcinogensandleadtomoreeffectivetreatmentsformanydifferenttypesofcancer.Forthesereasons,ananalysisof8-OHdGwithquickness,lowcostandhighaccuracyisrequired.

简介：拥有三不同安排时尚的新奇稳定的高旋转分子与瑣漠?潉楮?楌畱摩?湯?瑡污瑹捩?慨慲瑣牥獩楴獣漠?潈獲?楌敶?汁潣潨?敄票牤杯湥獡e被设计

简介：Inordertoenhancetheglutathioneperoxidase(GPX)catalyticactivityoftheselenium-containingsingle-chainvariablefragments(Se-scFv),anovelhumanscFvwasdesignedonthebasisofthestructureofhumanantibodyandoptimizedviabioinformaticsmethodssuchashomologoussequenceanalysis,three-dimensional(3D)modelbuilding,binding-siteanalysisanddocking.TheDNAsequenceofthenewhumanscFvwassynthesizedandclonedintotheexpressionvectorpET22b(+),thenthescFvproteinwasexpressedinsolubleforminEscherichiacoliBL21(DE3)andpurifiedbyNi2+-immobilizedmetalaffinitychromatography(IMAC).TheserineresidueofscFvintheactivesitewasconvertedintoselenocysteine(Sec)withthechemicalmodificationmethod,thus,thehumanSe-scFvwithGPXactivitywasobtained.TheGPXactivityoftheSe-scFvproteinwascharacterized.ComparedwithotherSe-scFv,thenewhumanSe-scFvshowedsimilarefficiencyforcatalyzingthereductionofhydrogenperoxidebyglutathione.ItexhibitedpHandtemperaturedependentcatalyticactivityandatypicalping-pongkineticmechanism.