Kawaguchi G, Kato N, Kashiwase K, Karaki S, Kohsaka T, Akaza T, Kano K, Takiguchi M
Department of Tumor Biology and Immunology, University of Tokyo, Japan.
Hum Immunol. 1993 Mar;36(3):193-8. doi: 10.1016/0198-8859(93)90125-k.
Two genes encoding HLA-B60 or HLA-B61 were cloned from Japanese and the exons of their genes were sequenced. One silent mutation was observed at the exon 1 between HLA-B60 (B40012) and B40011. Seven nucleotide substitutions were seen at the exon 3 between HLA-B61 (B4006) and B4002. Three substitutions at codon 95, CTC in B4002 to TGG in B4006, changed Leu in B4002 to Trp in B4006, while two substitutions at codon 97, AGC in B4002 and ACG in B4006, changed Ser in B4002 to Thr in B4006. Since B4002 shares the epitope of alloantibodies specific for HLA-B61, two HLA-B61 subtypes are discriminated by two amino acid substitutions at residues 95 and 97. B40012 and B*4006 differ by four amino acid substitutions on the beta sheet and five amino acid substitutions on the alpha 2 helix. Since the residues at the beta sheet seem hardly to affect the binding of alloantibody, it is suspected that the residues on the alpha 2 helix provide epitopes for alloantibodies that discriminate allospecificity between HLA-B60 and HLA-B61.
从日本人中克隆出了两个编码HLA - B60或HLA - B61的基因，并对其基因的外显子进行了测序。在HLA - B60（B40012）和B40011之间的外显子1处观察到一个沉默突变。在HLA - B61（B4006）和B4002之间的外显子3处发现了七个核苷酸替换。密码子95处的三个替换，B4002中的CTC变为B4006中的TGG，使B4002中的Leu变为B4006中的Trp，而密码子97处的两个替换，B4002中的AGC和B4006中的ACG，使B4002中的Ser变为B4006中的Thr。由于B4002与针对HLA - B61的同种抗体的表位相同，因此通过95和97位残基处的两个氨基酸替换区分出两种HLA - B61亚型。B40012和B*4006在β折叠上有四个氨基酸替换，在α2螺旋上有五个氨基酸替换。由于β折叠上的残基似乎几乎不影响同种抗体的结合，因此怀疑α2螺旋上的残基为区分HLA - B60和HLA - B61之间同种特异性的同种抗体提供表位。
