Myosin as cofactor and substrate in fibrinolysis

FEBS Letters

Machovich, Raymund³  Kolev, Krasimir¹  Owen, Whyte G.³  Ajtai, Katalin² 

[1] Department of Medical Biochemistry, Semmelweis University of Medicine, Budapest, Hungary;Department of Biochemistry and Molecular Biology, Mayo Clinic and Foundation, Rochester, MN 55905, USA;Section of Hematology Research, Mayo Clinic and Foundation, Rochester, MN 55905, USA

关键词: Plasminogen;    Plasminogen activator;    Myosin;   

DOI  :  10.1016/S0014-5793(97)00303-7

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Myosin accelerates plasminogen activation by tissue-type plasminogen activator (tPA), and is degraded extensively by plasmin. Myosin binds both tPA and plasminogen, and enhances activation of des_1-77-plasminogen by tPA but not by urokinase-type plasminogen activator (uPA). Myosin decreases K _M and increases k _cat for des_1-77-plasminogen activation by tPA, to yield catalytic efficiencies in excess of 8000 M⁻¹ s⁻¹. The effect of myosin is attributed to its C-terminal portion, the myosin rod. With a K _M of 3 μM, myosin is a high-affinity substrate for plasmin. The findings indicate that myosin is a cofactor for plasminogen activation and a substrate for plasmin.

【 授权许可】

Unknown