Proteolytic Activation of Single-chain Tissue-type Plasminogen Activator by Protease/α_2-Macroglobulin Complex Isolated from Human Ovarian Follicular Fluid(Endocrinology)

概要

論文の詳細を見る
α_2-Macroglobulin is a high-molecular-weight glycoprotein that inhibits a variety of endoproteases. Proteolytic enzymes associated with this inhibitor are thought to be unable to act on protein substrates. This paper reports that the α_2-macroglobulin fraction isolated from the follicular fluid of human ovaries is capable of proteolytically activating human single-chain tissue-type plasminogen activator. We demonstrated that a bound protease unlike plasma kallikrein was involved in the activation. This activity was maximally detected at pH values in the ranges 6-9, and was strongly inhibited by diisopropylfluorophosphate and aprotinin, indicating that the enzyme responsible for the activation is a serine protease. In summary, this paper describes for the first time that a protease complexed with α_2-macroglobulin exhibits detectable proteolytic activity toward the protein substrate single-chain tissue-type plasminogen activator.
1999-04-15