Mannose-pepstatin conjugates as targeted inhibitors of antigen processing
Mannose-pepstatin conjugates as targeted inhibitors of antigen processing
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DOI：
10.1039/b600060f
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发表时间：
2006-01-01
影响因子：
3.2
通讯作者：
Tabor, AB
中科院分区：
文献类型：
--
作者：
Free, P;Hurley, CA;Tabor, AB
抗原加工的分子细节，包括所涉及的酶的身份，它们的细胞内位置和它们的底物特异性，仍然没有完全理解。使用小分子抑制剂如胃蛋白酶抑制剂选择性抑制蛋白水解抗原加工酶如组织蛋白酶D和E已被证明是研究这些途径的有价值的工具。然而，胃酶抑素在水中溶解性差，并且进入抗原呈递细胞中的抗原加工区室的途径有限。我们已经合成了甘露糖-胃蛋白酶抑制剂缀合物和新甘露糖基化的BSA -胃蛋白酶抑制剂缀合物，作为抗原加工途径的体内研究的工具。相对于胃蛋白酶抑制剂，与甘露糖和新甘露糖基化BSA的缀合大大提高了缀合物的溶解度。甘露糖-胃蛋白酶抑制素缀合物显示对组织蛋白酶E的抑制没有减少，而新甘露糖基化BSA -胃蛋白酶抑制素缀合物显示抑制的一些损失，可能是由于空间因素。然而，在胃蛋白酶抑制剂和BSA之间掺入可裂解二硫键的新甘露糖基化BSA -胃蛋白酶抑制剂缀合物显示出对树突细胞的最佳摄取和对抗原加工的最佳抑制。
The molecular details of antigen processing, including the identity of the enzymes involved, their intracellular location and their substrate specificity, are still incompletely understood. Selective inhibition of proteolytic antigen processing enzymes such as cathepsins D and E, using small molecular inhibitors such as pepstatin, has proven to be a valuable tool in investigating these pathways. However, pepstatin is poorly soluble in water and has limited access to the antigen processing compartment in antigen presenting cells. We have synthesised mannose - pepstatin conjugates, and neomannosylated BSA - pepstatin conjugates, as tools for the in vivo study of the antigen processing pathway. Conjugation to mannose and to neomannosylated BSA substantially improved the solubility of the conjugates relative to pepstatin. The mannose - pepstatin conjugates showed no reduction in inhibition of cathepsin E, whereas the neomannosylated BSA - pepstatin conjugates showed some loss of inhibition, probably due to steric factors. However, a neomannosylated BSA - pepstatin conjugate incorporating a cleavable disulfide linkage between the pepstatin and the BSA showed the best uptake to dendritic cells and the best inhibition of antigen processing.