CAJ | 학술논문

目的克隆并测定中国人源蓝氏贾第鞭毛虫滋养体SUCH/89/BTMRI/2(C2)的表面变异抗原基因序列.方法提取蓝氏贾第鞭毛虫基因组DNA,PCR扩增表面变异抗原基因片段.将PCR产物连接到pMD19-T载体,并转化至大肠埃希菌JM109中进行序列测定.通过NT19.0软件对该基因的核苷酸和氨基酸序列进行分析,同时与基因库中已发表的蓝氏贾第鞭毛虫表面变异抗原基因进行同源序列比对.结果中国人源蓝氏贾第鞭毛虫基因全长为2 142 bp,编码1条长为713个氨基酸残基的多肽链,含有一个简单的开放阅读框(ORF).这一推测的多肽链序列富含半胱氨酸(11.8 mol%),且以CXXC模基序重复出现29次、GGCY四肽模基序出现1次及NXS重复3次在N端连接糖基化位点中.此外,这条多肽链还富含苏氨酸(10.2 mol%)、甘氨酸(12.1 mol%)和丙氨酸(10.1 mol%).同其他已确定的表面变异抗原(VSPs)一样,中国人源蓝氏贾第鞭毛虫SUCH/89/BTMRI/2(C2)株的表面变异抗原也含有高度保守的疏水性C末端.该表面变异抗原基因的核苷酸序列及推导的氨基酸序列同GenBank中Gillin发表的TSA417序列的同源性均高达99%.结论中国人源蓝氏贾第鞭毛虫滋养体表达的表面变异抗原基因具有与已鉴定的蓝氏贾第鞭毛虫表面变异抗原基因同样的特性.
목적 극륭병측정중국인원람씨가제편모충자양체SUCH/89/BTMRI/2(C2)적표면변이항원기인서렬.방법 제취람씨가제편모충기인조DNA,PCR확증표면변이항원기인편단.장PCR산물련접도pMD19-T재체,병전화지대장애희균JM109중진행서렬측정.통과NT19.0연건대해기인적핵감산화안기산서렬진행분석,동시여기인고중이발표적람씨가제편모충표면변이항원기인진행동원서렬비대.결과 중국인원람씨가제편모충기인전장위2 142 bp,편마1조장위713개안기산잔기적다태련,함유일개간단적개방열독광(ORF).저일추측적다태련서렬부함반광안산(11.8 mol%),차이CXXC모기서중복출현29차、GGCY사태모기서출현1차급NXS중복3차재N단련접당기화위점중.차외,저조다태련환부함소안산(10.2 mol%)、감안산(12.1 mol%)화병안산(10.1 mol%).동기타이학정적표면변이항원(VSPs)일양,중국인원람씨가제편모충SUCH/89/BTMRI/2(C2)주적표면변이항원야함유고도보수적소수성C말단.해표면변이항원기인적핵감산서렬급추도적안기산서렬동GenBank중Gillin발표적TSA417서렬적동원성균고체99%.결론 중국인원람씨가제편모충자양체표체적표면변이항원기인구유여이감정적람씨가제편모충표면변이항원기인동양적특성.
Objective To clone and sequence variant-specific surface antigen gene from Giardia lamblia isolate SUCH/89/BTMRI/2(C2) derived from human in China. Methods Total genomic DNA of G.lamblia was extracted and a full-length variant-specific surface antigen gene fragment was amplified by pelymerase chain reaction (PCR). The PCR product was cloned into pMD19-T simple-vector, transformed into an Escherichia coli JM109 strain and then sequenced. The sequence analysis for cloned fragment was finished by Vector NTI 9.0 software for the homology of Giardia variantspecific surface antigen gene to that of sequences publishend in GenBank. Results The full-length variant-specific surface antigen gone fragment from G. lamblia was found to be 2 142 bp, encoding a 713 amino acid polypeptide and contained a single open reading frame (ORF). The deduced polypeptide sequence was rich in cysteine (11.8 mol%), most of which occurred with in 29 copies of the 4-amino acid CXXC motif, one GGCY-tetrapeptide motifs and three NXS consensus N-linked glycosylation sites. This polypeptide was also rich in threonine (10.2 mol%), glycine (12.1 mol%) and alanine (10.1 mol%). Like other previously identified VSPs, it contained a highly conserved hydropbebic Cterminal region. The homology of G. lamblia SUCH/89/BTMRI/2(C2) variant-specific surface antigen gene to that of sequence (TSA417) published in GenBank was 99% both at the nueleotide and the amino acid levels. Conclusion The full length variant-specific surface antigen gene from the isolate of G. lamblia has the common characteristics with other previously identified VSPs.