以从树肝脏mRNA逆转录得到的Ⅰ链cDNA为模板 ,运用SMARTRACEPCR技术 ,扩增得到树载脂蛋白E(apoE)cDNA序列 ,并推导出apoE蛋白质的氨基酸序列 .利用分子生物学软件包PCGENE对氨基酸序列和二级结构进行分析和比较 .结果表明 ,树apoEcDNA序列 (作为新基因已被GenBank接收 ,登录号为AF 30 3830 )由 1138bp构成 ,其中 5′非翻译区 6 4bp ,3′非翻译区 135bp ,939bp组成一个完整开放阅读框架 ,与人apoEcDNA的同源性为 86 % .编码 313个氨基酸组成的apoE前体 ,包含 18个氨基酸构成的信号肽和 2 95个氨基酸组成的成熟蛋白 .与人apoE氨基酸序列的同源性为 78% .树apoE与人及其它种属动物apoE在氨基酸组成上相近 ,但比人apoE少4个氨基酸 ,比动脉粥样硬化易感动物家兔apoE多 2个氨基酸 .经Garnier法预测 ,树apoE蛋白二级结构与人apoE相似 ,螺旋构象 (helical) 6 9 9% ,伸展构象 (extended) 16 6 % ,转角构象 (turn)6 0 % ,无规则卷曲 (coil) 7 6 % .
Abstract
The first strand cDNA was prepared by reverse transcription using the mRNA isolated and purified from the liver tissue of tree shrew. By SMART RACE PCR, the apolipoprotein E cDNA sequence of tree shrew was obtained and the amino acid(AA) sequence was deduced. The primary and secondary structures of the protein were determined and predicted by using PCGENE software.The apolipoprotein E sequence of tree shrew,which was accepted by GenBank with accession number AF303830, consists of 1 138 nucleotides, including 64 bp 5′untranslated region, 135 bp 3′untranslated region and 939 bp open reading frame, and is identical by 86% with that of human. The deduced AA sequence is a 313 AA apoE precursor which consists of an 18 AA signal peptide and a 295 AA mature protein which is identical by 78% with that of human. The amino acid composition of tree shrew apoE is similar to that of human and other animal species apoE, but tree shrew apoE is 4 AA less than that of human while 2 AA more than that of the atherogenic rabbit. Predicted by the method of Garnier, the secondary structure of tree shrew apoE which may contain helical conformation 69 6%, extended 16 6%, turn 6 0%, coil 7 6%, is also similar to that of human apoE .
关键词
树鼩 /
载脂蛋白E /
cDNA /
蛋白质结构
{{custom_keyword}} /
Key words
tree shrew /
apolipoprotein E /
cDNA /
protein structure
{{custom_keyword}} /
{{custom_sec.title}}
{{custom_sec.title}}
{{custom_sec.content}}
参考文献
1 WangKQ ,ChenBS ,XieYH ,XueH .AretreeshrewsandBeijingducksgoodmodelsforthestudyoftheantiatherogenietyHDL ?In:WoodfordFP ,DavignonJ ,SnidermanAeds.AtherosclerosisX ,Am sterdam:EISevierPress,1995:126～131
2 MahleyRW ,HuangY .ApolipoproteinE :fromatherosclerosistoAlzheimer’sdiseaseandbeyond.CurrOpinLipidol,1999,10:207～217
3 WilsonC ,WardellMR ,WeisgraberKH ,MahleyRW ,AgardDA .Three dimensionalstructureoftheLDLreceptor bindingdomainofhu manapolipoproteinE .Science,1991,252:1817～1822
4 MahleyRW ,HuangY ,RallSC .PathogenesisoftypeⅢhyperli poproteinemia(dysbetalipoproteinemia):questions,quandaries,andparadoxes.JLipidRes,1999,40:1933～1949
5 AltschulSF ,MaddenTL ,Sch fferAA ,ZhangJH ,ZhangZ ,MillerW ,D .LipmanDJ.GappedBLASTandPSI BLAST :anewgenerationofproteindatabasesearchprograms,NucleicAcidsRes,1997,25:3389～3402
6 GarnierJ,OsguthorpeDJ,RobsonB .Analysisoftheaccuracyandim plicationsofsimplemethodsforpredictingthesecondarystructureofglobularproteins.JMolBiol,1978,120:97～120
7 CherylAD ,DavidPC ,GrahamCP ,LindaKC .Structuraloffeatu uresofsyntheticpeptidesofapolipoproteinEthatbindtheLDLrecep tor.JLipidRes,1995,36(1):80～88
8 DongLM ,WilsonC ,WardellMR ,SimmonsT ,MahleyRW ,Weis graberKH ,AgardDA .HumanapolipoproteinE .Roleofarginine61inmediatingthelipoproteinpreferencesoftheE3andE4isoforms.JBiolChem,1994,269(35):22358～22365
9 ChenchikA ,ZhuY ,DiatchenkoL ,LiR ,HillJ,SiebertP .Genera tionanduseofhighqualitycDNAfromsmallamountsoftotalRNAbySMARTPCR .In:SiebertP ,LarrickJeds.RT PCRMethodsforGeneCloningandAnalysis.BioTechniquesBooks,MA ,1998,305～319
10 HaoQL ,YaminTT ,PanTC ,ChenSL ,ChenBS .Isolationandcharacterizationofafull lengthrabbitapolipoproteinEcDNA .Athero sclerosis,1987,66,125～130
11 HixsonJE ,CoxLA ,BorensteinS .ThebaboonapolipoproteinEgene:Structure,expression,andlinkagewiththegeneforapolipoproteinC I.Genomics,1988,2:315～323
12 RajavashisthTB ,KapteinJS ,ReueKL ,LusisAJ.Evolutionofapo lipoproteinE :Mousesequenceandevidenceforan11 nucleotideances tralunit.ProcNatlAcadSciUSA ,1985,82:8085～8089
{{custom_fnGroup.title_cn}}
脚注
{{custom_fn.content}}
PDF(268 KB)
