恶性疟原虫裂殖子表面主要蛋白与人红细胞结合的研究(英文)

目的 :研究恶性疟原虫裂殖子表面主要蛋白 - 1( P195)与人红细胞的结合作用。方法 :在大肠杆菌中分 8段表达 MAD2 0株恶性疟原虫 P195蛋白。各段表达蛋白经复性及用同位素 12 5I标记后与人红细胞进行结合实验。结果 :氨基酸序列为 12 3- 30 2 ( M3) ,384 - 595( M6) ,10 78- 12 51( M9)的三段蛋白具有红细胞结合作用。其中 M6不能与胰酶处理过的红细胞结合 ,且与正常红细胞结合的 M6片段能被酸性缓冲液洗脱。而 M3,M9与红细胞结合不受胰酶影响 ,且不能被酸性缓冲液洗脱。结论 :M6与红细胞的结合位点可能为红细胞膜表面蛋白受体 ,M3,M9与红细胞的结合点不在膜表面 ,而在红细胞内。

STUDIESON BINDING DOMAINSOF MAJOR MEROZOITE SURFACE PROTEIN OF PLASMODIUM FALCIPARUM TO HUMAN ERYTHROCYTE

AIM:To understand the interaction between a195- kilodalton protein,P195, on the surface of Plasmodium falciparum merozoite and human erythrocyte.METHODS:P195 was expressed in eight fragments in E.coli.After being refolded,the expressed proteins were la- belled with12 5 I,and incubated with human erythrocytes.RESULTS:According to binding assay, three fragments of P195:M3,M6,M9were found to have ability to bind to human erythrocyte. M6,which is equal to amino acid( AA) sequence from384 to595,could bind to human erythro- cytes but not to trypsin treated human erythrocytes,and the binding could be eluted by low p H buffer solution. M3( AA 12 3to 30 2 ) and M9( AA 10 78to 12 51) also have the ability to bind to human erythrocytes,but the binding was not affected by trypsin treatment and low p H buffer elu- tion. CONCL USION:The binding site of M6might be a surface protein receptor of human ery- throcytes,while the binding site of M3and M9might be an intracellular componentof human ery- throcyte.