庚型肝炎病毒非结构基因(NS)5区部分序列的一级结构及其变异

Primary structure and variability of partial sequences in nonstrutural gene 5 regin of hepatitis G virus.

测定庚型肝炎病毒（ＨＧＶ）非结构基因５（ＮＳ５）区部分基因序列。方法从３例献血员，２例肝硬化患者及１例非甲－戊型肝炎患者血清中通过逆转录－套式－聚合酶链反应（ＰＣＲ）扩增出长９９４ｂｐ的ｃＤＮＡ序列，ＰＣＲ产物纯化后以双脱氧末端终止法测定其序列。结果所分离的６株ＨＧＶＮＳ５区部分核苷酸序列与国外报道的３株（ＧＢＶ－Ｃ、ＰＮＦ２１６１、Ｒ１０２９１）比较，同源性为８７．２％～９３．９％；６株间同源性为９０．１％～９３．８％。根据所测得的６株ｃＤＮＡ序列推导出其编码的氨基酸序列，与国外发表的３株序列相比，同源性在９３．６％～９８．７％，６株之间为９３．６％～９８．４％。在此区内发现有１６个保守的脯氨酸残基及８个保守的半胱氨酸残基。结论从不同慢性肝脏疾病患者及献血员血清中分离出６株ＨＧＶ，其ＮＳ５区部分序列在核苷酸水平及氨基酸水平均较保守。

Objective To sequence partial genome of hepatitis G virus(HGV)in the sera of patients with different chronic liver disease and paid donors.Methods Total nucleic acids were extracted from the sera of 3 paid donors,2 patients with liver cirrhosis,and 1 patient with non A E chronic hepatitis,then subjected to reverse transcriptase nested polymerase chain reaction (PCR) with primers derived from the putative nonstructural gene 5 (NS5).PCR products were directly sequenced after purification.Results Partial HGV NS5gene of 6isolates exhibited 87.2% to 93.9% nucleotide sequence identities with 3 reported HGV isolates(GBV C,PNF2161,R10291),while the nucleotide homologies among the 6 isolates were 90.1%to93.8%. And 93.6% to 98.7% homolies were found at the deduced amino acid level when comparing the 6 isolates with 3 reported ones,while 93.61% to 98.40% amino acid identities were found among 6 isolates.In the region sequenced,there were1 6 conserved proline residues and 8conserved cysteine residues.Conclusions Six isolates of HGV were obtained from different cases and donors.The partial nucleotide sequences,as well as amino acid sequences,of the putative NS5 region of HGV were relatively conserved.This region of the genome may be suitable for the development of diagnosis reagents.