BIOCHEMICAL CYTOLOGY OF HOST-PARASITE INTERACTIONS IN PARASITIC PROTOZOA

利什曼原虫和锥虫的细胞生物学和生物化学 作为细胞内和细胞外寄生的模型被研究， 分别进行了分析。因为宿主和寄生虫之间的所有相互作用都发生在 寄生虫表面膜(SM)的水平重点放在：1)其 综合生化特性和2)确定其在 寄生虫的生存。 在L。SM中鉴定出约65 kDa的亲和素结合糖蛋白。 多诺瓦尼(L.d.)能在羧基酶中发挥作用的前鞭毛体 反应。丹参和丹参的主要碳水化合物组成 用Western blotts方法鉴定了L.D.的糖蛋白。动力学 对乳杆菌合成和分泌可溶性酸性磷酸酶(SACP)进行了研究。 确定物及其糖基化事件的鉴定。SACP被提纯并 测定了其N端氨基酸序列。补体成分C3 主要以IC3b的形式与L.D.的SM结合，大多数从 作为裂解片段的细胞可能是从寄生虫SM蛋白酶中重新利用的 活动。一种促进扩散介导的戊糖转运系统是 分离得到L.d.SM 3‘-核苷酸酶(3’-NT) 并鉴定为43 kDa的甘露糖糖蛋白。假想的克隆 从一株L.d中分离到编码3‘-NT和SM gp-63抗原。 基因组文库。对L.D.SM 5‘-核苷酸酶进行了部分纯化。 推测为72 kDa的甘露糖化糖蛋白。两个截然不同的 质膜和线粒体中有质子-ATPase的特征。 分别进行了分析。L.D.SM D-葡萄糖转运蛋白的特征是19 KDA甘露糖化糖蛋白。此外，55-62 kDa的促甲状腺激素结合 在L.d.的SM中有蛋白质表达。 目前的结果为寄生虫提供了进一步的功能特征。 可能被证明是化疗和/或靶标的SM成分 作为免疫预防的药物。

The cell biology and biochemistry of Leishmania and Trypanosoma are investigated as models of intra- and extracellular parasitism, respectively. As all interactions between host and parasite occur at the level of the parasite surface membrane (SM) emphasis is placed on: 1) its integrated biochemical characterization and 2) defining its roles in parasite survival. About 65 kDa avidin-binding glycoprotein was identified in the SM of L. donovani (L. d.) promastigotes which could function in carboxylase reactions. The major carbohydrate constituents of both SM and released glycoproteins of L. d. were identified using Western blots. The kinetics of synthesis and secretion of soluble acid phosphtase (SAcP) by L. d. were determinend and its glycosylation events identified. SAcP was purified and its N-terminal amino acid sequence determined. Complement component C3 binds to the SM of L. d. predominantly as iC3b and most is released from cells as cleavage fragments presumably reuslting from parasite SM protease activity. A facilitated diffusion-mediated pentose transport system was characterized in L. d. The L. d. SM 3'-nucleotidase (3'-NT) was isolated and charcterized as a 43 kDa mannose-glycoprotein. Clones putatively encoding for 3'-NT and a SM gp-63 antigen were isolated from a L. d. genomic library. The L. d. SM 5'-nucleotidase was partially purified and putatively identified as a 72 kDa mannosylated glycoprotein. Two distinct proton-ATPases were characterized in the SM and mitochondrion of L. d., respectively. The L. d. SM D-glucose transporter was characterized as a 19 kDA mannosylated-glycoprotein. Further, a 55-62 kDa thyrotropin binding protein was demonstrated in the SM of L. d. The current results provide further functional characterization of parasite SM constituents which might prove useful as targets for chemotherapy and/or as agents for immunoprophylaxis.