Doménech N, Castaño R, Goulmy E, López de Castro J A
Department of Immunology, Fundación Jiménez Díaz, Consejo Superior de Investigaciones Científicas, Madrid, Spain.
Immunogenetics. 1988;28(3):143-52. doi: 10.1007/BF00375853.
The structure of an HLA-A2.4 functional variant (A2.4c) expressed on donor KLO has been examined by comparative peptide mapping with other HLA-A2 antigens of known structure and radiochemical sequencing. All the peptide differences between A2.4c and A2.1 could be accounted for by five amino acid changes at positions 9, 43, 66, 95, and 156. The nature of residues 9, 43, and 95 in A2.4c was determined by sequencing to be identical to those in A2.2Y. The nature of residue 156 in A2.4c was also assigned as identical to that in A2.2Y on the basis of the identity of the corresponding peptide in its chromatographic comparison with A2.2Y. Position 66 was unique to A2.4c. It was determined to be an Asn residue instead of the Lys present in all other HLA-A2 antigens of known structure. This was the only detected amino acid difference between A2.4c and A2.2Y. The results indicate that, from a structural point of view, A2.4c is most closely related to the A2.2 subtype antigens and not to other A2.4 antigens. The data are compatible with the assumption that A2.4c was derived from A2.2Y by a single point mutation event.
通过与已知结构的其他HLA - A2抗原进行比较肽图谱分析和放射化学测序，对供体KLO上表达的HLA - A2.4功能变体（A2.4c）的结构进行了研究。A2.4c与A2.1之间所有的肽差异都可归因于第9、43、66、95和156位的五个氨基酸变化。通过测序确定A2.4c中第9、43和95位残基的性质与A2.2Y中的相同。基于A2.4c中相应肽与A2.2Y在色谱比较中的一致性，A2.4c中第156位残基的性质也被确定为与A2.2Y中的相同。第66位是A2.4c所特有的。经测定它是一个Asn残基，而不是已知结构的所有其他HLA - A2抗原中存在的Lys残基。这是A2.4c与A2.2Y之间唯一检测到的氨基酸差异。结果表明，从结构角度来看，A2.4c与A2.2亚型抗原关系最为密切，而与其他A2.4抗原无关。这些数据与A2.4c是由A2.2Y通过单点突变事件衍生而来的假设相符。
