乙型肝炎病毒C基因多态性及其蛋白特性分析

目的:调查温州医学院大学生人群乙型肝炎病毒(HBV)C基因多态性及其HBc蛋白特性变化,为了解乙肝病毒核心抗原(HBcAg)变异提供理论依据。方法:采用HBV-C基因特异性引物对21份温州医学院大学生HBV携带者(血清学检测为大三阳患者)血清标本进行PCR扩增鉴定,并取19份PCR检测阳性产物直接测序;进一步用Vector NTI 8.0和DNA Star软件分析HBV-C基因多态性及HBc蛋白特性的变化。结果:21份标本中,HBV-C DNA阳性率达90.48%(19/21),与标准基因序列(Gen Bank X01587)比较,HBV-C基因同源性为93.3%～95.1%。HBV-C基因分别形成51种突变模式,其中一处由于核苷酸的改变,翻译的氨基酸也发生了相应的改变,此处氨基酸序列的第130处脯氨酸(Pro)突变为苏氨酸(Thr),其余标本均为同义突变;但突变处编码蛋白在亲水性、表面可及性及抗原性与标准株相比较无明显变化。结论:温州医学院大学生HBV携带者的HBV C基因具有多态性,但是由C基因决定的核心蛋白序列相对保守。

Analysis of C gene polymorphism and C protein property of hepatitis B virus (HBV)

Objective: To study the character of HBV C gene from college students in Wenzhou area,and analysis mutations of its polymorphism and protein property,providing theoretical basis of the HBV core antigen variations.Methods: The HBV DNA was extracted from the serum of HBV carriers with the HBsAg,HBcAg,HBeAg positive and anti-HBs,anti-HBe negative.The C gene of HBV was amplified with PCR by C gene specific primers from the 21 serum samples respectively,and C gene products of 19 sampls were identified by sequencing,the C gene polymorphism and HBcAg protein property were further analyzed with bio-soft of Vector NTI 8.0 and DNAstar.Results: Compared with standard C gene of HBV sequence(GenBank X01587),gene homology was 93.3%～95.1% and 51 mutations of the C gene were found in the 19 serum samples.But there was only one amino acid mutation which was Pro to Thr at coden 130 and compared with the standard HBV C gene were not found in hydrophilicity,surface probability and antigenic index compared with the standard C protein property.Conclusion: The results show that some mutations had taken place in the nucleotide sequence of C gene of HBV obtained from the serum of HBV carriers who were college students in Wenzhou area.However,the core protein sequence determined by the C gene is relatively conservative.