1、南京農(nóng)業(yè)大學(xué)碩士學(xué)位論文人源β防御素6的原核表達(dá)及純化姓名：馬鵬申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：動(dòng)物學(xué)指導(dǎo)教師：賴仞201012ABSTRACTPURIFICArl0NANDPROKARYOTICEXPI之ESSIONOFHUMANBETADEFENSIN6ABSTRACTAntimicrobialpeptides(AMPs)areimportantpartsofthenaturalimmunesysteminvivoTheyareusuall

2、ycomposedby12~45aminoacidsTheymainlyexistincationicformbecauseoftheirrichinarginineandlysineresiduesAtpresent，differenttypesofantimicrobialpeptidesfromvariousspecies，includingbacteriafungi，plants，insects，amphibians，fish，

3、birds，mammalsandhumans，areseparatedandidentifiedMostantimicrobialpeptideshavebroadspectrumantimicrobialactivityTIleyhaveakillingeffectonGrampositivebacteriaGramnegativebacteriaandfungiatverylowconcentrationsandsomeofthem

4、eveninthenmolconcentrationCancompletelyinhibitbacterialgrowthComparedwithtraditionalantibiotics，thebiggestadvantageofAMPsisthattlleyworkrapidlyandhardlyleadtodrugresistanceDefensinsarethelargestsubfamilyofantimicrobialpe

5、ptidesfamily勰animportantsetofendogenousAMPsPossesingstablemolecularstructureandmultiplebiologicalactivities，theyareanimportantcomponentofinnateimmunityAccordingtothedifferentspatialstructure，defensinscarlbedividedintothr

6、eecategories：a—defensins，13defensinsand0defensinsInthefieldofanimalscience，knownasawiderantibacterialspectrum，13defensinshardlyleadtodrugresistanceandtoxicityBecauseofgoodresearchvalue，13defensinsattractwidespreadattenti

7、onandhasbecomearesearchhotspotinrecentyearsAthomeandabroadfewabouttheresearchofhumanIBdefensin6hasbeenreportedInthispaperrecombinanthuman13defensin6(hDefb6)expressionplasmidpET32a()hDefb6wasconstructedbymeansofgeneticeng

8、ineeringandhDefb6WassuccessfullyexpressedthroughpETprokaryoticexpressionsysteminEscherichiacoliBL21(DE3)Separatedandpurifiedbynickelaffinitychromatographyformicaciddigestion，SephadexG50gelchromatographyandreversed—phaseh

9、ighperformanceliquidchromatography(Re—HPLC)andSOforth，purehDefb6wasobtainedAntibacterialtestresultsshowedthat：theminimumconcentrationsofhDefb6forinhibitingthegrowthofGramnegativebacteriaEscherichiacoli(ATCC25922)andfungi

10、Candidaalbicans(ATCC2002)are37“g‘mL1and50ltg‘mL一，respectivelyTheinhibitiontothegrowthofgrampositivebacteriumStaphylococcusaureus(ATCC2592)wasnotdetectedwhentheconcentrationofhDefb6was200lxgmL一KEYWORDS：humanbetadefensin6；