tailieunhanh - Báo cáo khóa học: Nonlysine-analog plasminogen modulators promote autoproteolytic generation of plasmin(ogen) fragments with angiostatin-like activity

We recently discovered several nonlysine-analog conforma-tional modulators for plasminogen. These include SMTP-6, thioplabin B and complestatin that are low molecular mass compounds of microbial origin. Unlike lysine-analog mod-ulators,which increaseplasminogenactivationbut inhibit its binding to fibrin, the nonlysine-analog modulators enhance both activation and fibrin binding of plasminogen. Here we show that some nonlysine-analog modulators promote autoproteolyticgenerationof plasmin(ogen) derivativeswith its catalytic domain undergoing extensive fragmentation (PMDs), which have angiostatin-like anti-endothelial activ-ity | Eur. J. Biochem. 271 809-820 2004 FEBS 2004 doi Nonlysine-analog plasminogen modulators promote autoproteolytic generation of plasmin ogen fragments with angiostatin-like activity Shigeki Ohyama Tomotaka Harada Toshihiro Chikanishi Yutaka Miura and Keiji Hasumi Department of Applied Biological Science Tokyo Noko University Saiwaicho Fuchu-shi Tokyo Japan We recently discovered several nonlysine-analog conformational modulators for plasminogen. These include SMTP-6 thioplabin B and complestatin that are low molecular mass compounds of microbial origin. Unlike lysine-analog modulators which increase plasminogen activation but inhibit its binding to fibrin the nonlysine-analog modulators enhance both activation and fibrin binding of plasminogen. Here we show that some nonlysine-analog modulators promote autoproteolytic generation of plasmin ogen derivatives with its catalytic domain undergoing extensive fragmentation PMDs which have angiostatin-like anti-endothelial activity. The enhancement of urokinase-catalyzed plasminogen activation by SMTP-6 was followed by rapid inactivation of plasmin due to its degradation mainly in the catalytic domain yielding PMD with a molecular mass ranging from 68 to 77 kDa. PMD generation was observed when plasmin alone was treated with SMTP-6 and was inhibited by the plasmin inhibitor aprotinin indicating an autoproteolytic mechanism in PMD generation. Thioplabin B and com-plestatin two other nonlysine-analog modulators were also active in producing similar PMDs whereas the lysine analog 6-aminohexanoic acid was inactive while it enhanced plasminogen activation. Peptide sequencing and mass spectrometric analyses suggested that plasmin fragmentation was due to cleavage at Lys615-Val616 Lys651-Leu652 Lys661-Val662 Lys698-Glu699 Lys708-Val709 and several other sites mostly in the catalytic domain. PMD was inhibitory to proliferation migration and tube formation of endothelial cells at concentrations of .