人C5aR(CD88)序列结构分析及其B细胞表位预测

ANALYSIS OF CHARACTERISTICS AND PREDICATION OF BCELL EPITOPES FOR THE HUMAN C5a RECEPTOR

采用ＫｙｔｅＤｏｏｌｉｔｔｌｅ氨基酸亲水性标准及Ｂａｉｒｏｃｈ的ＧＧＢＳＭ方案对人Ｃ５ａＲ分子的亲水性基序、Ｂ细胞表位及二级结构进行了预测，并用吴氏建立的Ｂ细胞表位预测方法进行评述。结果显示，不同的预测方案所得结果一致，人Ｃ５ａＲ分子中，构成螺旋结构，伸展构象及无规卷曲的氨基酸残基数比例分别为３３．７％，３４．６％，３１．７％。三个高亲水性区域为第１５～１８位的ＤＤＫＤ，第１９５～２００位的ＤＫＲＲＥＲ和第３３０～３３３位的ＲＥＳＫ，其Ａｈ值分别为３．０、３．０、２．３２。其平均抗原性指数ＡＩ值分别为０．０６４、０．０９１、０．０７０。Ｎ－端第９～３０氨基酸序列的ＡＩ＝０．０４２，是Ｂ细胞优势表位区，以此制作短肽单克隆抗体是可行的。

The hydrophilicity profile,Bcell dominant epitopes and secondary structures of the receptor for human C5a were predicted by using kyte & Doolittle′s method and Bairoch′s method.The results were as followes:The Ah(Average hydrophilicity)of D15DKD,D195KRRER,R330ESK profile,Which were the high hydrophilicity profile,were 3.0,3.0,2.32,respectively.The percentage of amino acid in Helical,Extended and coil structure is 33.7%,34.6%,31.7%,respectively.The Nterminal No.9～30 was the predominant epitope of the Bcells.This poly peptide could be made for the production of sitedirected monoclonal antibody.