Analysis of a structural determinant in thrombin-protease nexin 1 complexes that mediates clearance by the low density lipoprotein receptor-related protein.
Analysis of a structural determinant in thrombin-protease nexin 1 complexes that mediates clearance by the low density lipoprotein receptor-related protein.
复制标题
凝血酶-蛋白酶连接蛋白 1 复合物中介导低密度脂蛋白受体相关蛋白清除的结构决定因素的分析。
DOI：
10.1074/jbc.274.1.275
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发表时间：
1999
期刊：
影响因子：
--
通讯作者：
Knauer,DJ
中科院分区：
文献类型：
--
作者：
Knauer,MF;Crisp,RJ;Kridel,SJ;Knauer,DJ
We recently identified a synthetic peptide, Pro47–Ile58, derived from the mature protease nexin 1 (PN1) sequence, that inhibited the low density lipoprotein receptor-related protein (LRP)-mediated internalization of thrombin-PN1 (Th-PN1) complexes. Presently, we have analyzed this sequence in Th-PN1 complex catabolism using two independent approaches: 1) An antibody was generated against Pro47–Ile58, which inhibited complex degradation by 70% but had no effect on the binding of the complexes to cell surface heparins. This places the structural determinant in PN1 mediating complex internalization by the LRP outside of the heparin-binding site. 2) Site-directed genetic variants of PN1 with a single Ala substitution at His48, or two Ala substitutions, one at His48and another at Asp49, were expressed in Sf9 insect cells. The catabolic rate of complexes formed between Th and the singly substituted and doubly substituted variants was lowered to 50 and 15%, respectively, when compared with the catabolic rate of native Th-PN1 complexes. This is the first analysis of a structural determinant in aserineproteaseinhibitor (SERPIN) required for LRP-mediated internalization and in part may explain the cryptic nature of this site in the unreacted serine protease inhibitor.
