Deans J A, Jean W C
Department of Immunology, UMDS, Guy's Hospital Medical School, London, U.K.
Mol Biochem Parasitol. 1987 Nov;26(1-2):155-66. doi: 10.1016/0166-6851(87)90139-3.
Two monoclonal antibodies, which prevent merozoites attaching to or invading erythrocytes, react with the same or closely apposed epitopes on a minor 66 kDa Plasmodium knowlesi antigen. The antigen is processed, at the time of schizont rupture and merozoite release, to 44 and 42 kDa molecules which are present on the merozoite surface [Deans, J. A. et al. (1984) Mol. Biochem. Parasitol. 11, 189-204]. The monoclonal antibody-defined epitope, which is expressed only once on the 66 kDa molecule, is formed by a tertiary folding of the polypeptide chain (minimum size 42 kDa). The conformation of the epitope is maintained by weak intramolecular forces of attraction, rendering the epitope extremely labile; it is completely destroyed by treatment with sodium dodecyl sulphate (SDS). Polyclonal monospecific antiserum raised against SDS-treated antigen did not inhibit parasite proliferation whereas a polyclonal antiserum raised against native antigen was inhibitory. It is postulated that the monoclonal antibody-defined antigenic determinant is crucial for merozoite invasion.
两种单克隆抗体可阻止裂殖子附着或侵入红细胞，它们与诺氏疟原虫一种66 kDa次要抗原上相同或紧密相邻的表位发生反应。在裂殖体破裂和裂殖子释放时，该抗原被加工成44 kDa和42 kDa的分子，这些分子存在于裂殖子表面[迪恩斯，J. A.等人（1984年）《分子生物化学寄生虫学》11卷，第189 - 204页]。单克隆抗体界定的表位在66 kDa分子上仅表达一次，由多肽链的三级折叠形成（最小尺寸为42 kDa）。表位的构象通过弱分子内吸引力得以维持，这使得表位极其不稳定；用十二烷基硫酸钠（SDS）处理会使其完全被破坏。针对经SDS处理的抗原产生的多克隆单特异性抗血清不抑制寄生虫增殖，而针对天然抗原产生的多克隆抗血清具有抑制作用。据推测，单克隆抗体界定的抗原决定簇对裂殖子入侵至关重要。
