A synthetic peptide derived from staphylokinase enhances plasminogen activation by tissue-type plasminogen activator

作者：Okada K; Ueshima S^*; Matsuno H; Nagai N; Kawao N; Tanaka M; Matsuo O

来源：Journal of Thrombosis and Haemostasis, 2011, 9(5): 997-1006.

DOI：10.1111/j.1538-7836.2011.04257.x

• endothelial cell
• plasminogen
• plasminogen activation
• synthetic peptide
• thrombolysis
• tissue-type plasminogen activator

Background: A synthetic nonadecapeptide (SP; GPYLMVNVTGVDGKGNELL) previously enhanced the activation of plasminogen by the SAK/plasmin complex. Objectives: To identify the binding site for SP on plasminogen and elucidate the effects of SP on plasminogen activation by the tissue-type plasminogen activator (t-PA). Methods: The effects of SP on plasminogen activation were estimated using a chromogenic substrate and from the cleavage of plasmin on SDS-PAGE under reduced conditions. The binding to SP of various peptides derived from the amino acid sequence of plasminogen was analyzed with an IAsys biosensor. The SP-mediated structural change to plasminogen was analyzed by circular dichroism(CD) spectroscopy. The thrombolytic effects of SP were examined using a mouse model of thrombosis. Results: SP enhanced the activation of plasminogen by t-PA. The catalytic efficiency (k(cat)/K(m)) of Glu-plasminogen activation by t-PA was 11.4-fold higher in the presence than absence of SP. The binding of SP to plasminogen was greatly inhibited by a synthetic peptide, FEKDKYILQGVTSWGLG, located close to the C-terminal of the plasminogen B region. Near-ultraviolet CD spectra of the complex between SP and Glu-plasminogen significantly differed from those of Glu-plasminogen. When SP was administered in a mouse model of thrombosis, early recanalization was observed in a dose-dependent manner. However, SP did not cause recanalization in t-PA gene-deficient mice. Conclusions: SP bound to the B region and promoted the activation of plasminogen by t-PA, and then induced effective thrombolysis.

• 出版日期2011-5