Suramin and suramin analogues inhibit merozoite surface protein-1 secondary processing and erythrocyte invasion by the malaria parasite Plasmodium falciparum
Suramin and suramin analogues inhibit merozoite surface protein-1 secondary processing and erythrocyte invasion by the malaria parasite Plasmodium falciparum
复制标题
DOI：
10.1074/jbc.m306603200
复制
发表时间：
2003-11-28
影响因子：
4.8
通讯作者：
Holder, AA
中科院分区：
文献类型：
--
作者：
Fleck, SL;Birdsall, B;Holder, AA
疟疾裂殖子侵入红细胞;并且作为该侵入过程中的必要步骤，恶性疟原虫裂殖子表面蛋白-1（MSP 1（42））的42-kDa片段在二次加工步骤中被进一步切割成33-kDa N-末端多肽（MSP 1（33））和19-kDa C-末端片段（MSP 1（19））。苏拉明显示出抑制裂殖子侵入和MSP 142蛋白水解切割。通过在蛋白质存在下的荧光增强和等温滴定量热法测定，该多磺化萘脲直接结合重组恶性疟原虫MSP 1（42）（K-d = 0.2 μ M）和间日疟原虫MSP 1（42）（K-d = 0.3 μ M）。苏拉明与间日疟原虫MSP 1（33）（K-d = 1.5 μ M）次级加工产物的结合仅稍弱（荧光测量），但与MSP 1（19）（K-d类似于15 mM）的结合非常弱（NMR测量）。使用NMR测量，MSP 1（19）中的几个残基涉及与苏拉明的相互作用。一系列的对称苏拉明类似物，不同的芳香环的数量和取代模式的末端萘胺基团进行了检查，在入侵和处理试验。两个类的类似物与两个或四个桥环被发现是活跃的，在这两个试验中，而其他两个类没有桥环是无活性的。我们认为苏拉明和相关化合物通过与MSP 1结合并阻止其被二次加工蛋白酶裂解来抑制红细胞侵袭。结果表明，入侵过程中的酶促事件是药物开发的合适目标，并验证了抑制剂结合大分子底物以防止其被蛋白酶水解的新概念。
Malarial merozoites invade erythrocytes; and as an essential step in this invasion process, the 42-kDa fragment of Plasmodium falciparum merozoite surface protein-1 (MSP1(42)) is further cleaved to a 33-kDa N-terminal polypeptide (MSP1(33)) and an 19-kDa C-terminal fragment (MSP1(19)) in a secondary processing step. Suramin was shown to inhibit both merozoite invasion and MSP142 proteolytic cleavage. This polysulfonated naphthylurea bound directly to recombinant P. falciparum MSP1(42) (K-d = 0.2 muM) and to Plasmodium vivax MSP1(42) (K-d = 0.3 muM) as measured by fluorescence enhancement in the presence of the protein and by isothermal titration calorimetry. Suramin bound only slightly less tightly to the P. vivax MSP1(33) (K-d = 1.5 muM) secondary processing product ( fluorescence measurements), but very weakly to MSP1(19) (K-d similar to15 mM) (NMR measurements). Several residues in MSP1(19) were implicated in the interaction with suramin using NMR measurements. A series of symmetrical suramin analogues that differ in the number of aromatic rings and substitution patterns of the terminal naphthylamine groups was examined in invasion and processing assays. Two classes of analogue with either two or four bridging rings were found to be active in both assays, whereas two other classes without bridging rings were inactive. We propose that suramin and related compounds inhibit erythrocyte invasion by binding to MSP1 and by preventing its cleavage by the secondary processing protease. The results indicate that enzymatic events during invasion are suitable targets for drug development and validate the novel concept of an inhibitor binding to a macromolecular substrate to prevent its proteolysis by a protease.