HLA新等位基因B＊ 13：92的确认及蛋白质三级结构的初步分析

Identification of A Novel HLA-B* 13:92 Allele and Analysis of Its 3D Model Structure

目的：人类白细胞抗原（HLA）新等位基因B＊13：92的确认及蛋白质空间结构的分析。方法：应用多聚酶链式反应-基于测序的分型技术（polymerase chain reaction sequencing based typing,PCR-SBT）进行HLA常规实验分型,HLA-B位点分型结果与等位基因B＊13：01：01,B＊58：01：01在189位有1个碱基不匹配,不能指定为任何HLA-B位点等位基因,用针对B＊13、B＊58的组特异性测序引物（GSSP）,确认与同源性最高的HLA等位基因序列的差异,使用SWISS-MODEL方法建立该新基因的空间模型并进行分析。结果：测序结果证实,该等位基因与其同源性最高的等位基因是B＊13：01：01,两者的差异是在第2外显子189位的C〉A,密码子39由GAC变为GAA,编码的氨基酸由天冬氨酸（D）转变为谷氨酸（E）。空间结构分析表明替代氨基酸位于抗原肽结合区α螺旋上。结论：该等位基因是在中国广西壮族人群发现的一个新HLA-B位点等位基因,世界卫生组织（WHO）HLA命名委员会将其正式命名为HLA-B＊13：92。

Objective：To identify a novel human leukocyte antigen（HLA） allele HLA-B＊ 13：92 and analyze 3D model of HLA molecule.Methods：Polymerase chain reaction sequencing-based（PCR-SBT） was used in routine HLA typing,the B locus typing results of one sample was one base mismatch with B＊ 13：01：01,B＊ 58：01：01 at locus 189,The Group Specific Sequencing Products（GSSP） which target at B ＊ 13 and B＊ 58 were used to confirm difference between the new allele and highest homologous allele,then the new allele was modeled by Swiss-model to its 3D structure.Results：The sequencing results showed that the new allele with highest homologous allele B＊ 13：01：01 was the difference in the second exon at position 189 C 〉 A（codon 39 GAC 〉 GAA）,39 Asp（D） was changed to Glu（E）.The amino acid substitution at residue 39 of the HLA polypeptide was located in α-helices of antigenic peptidebiding region.Conclusion：This allele is a new HLA-B allele found in Chinese Guangxi Zhang population and has been designated as HLA-B＊ 13：92 by the World Health Organization（WHO） HLA Nomenclature Committee.