Effective activation of the proenzyme form of the urokinase‐type plasminogen activator (pro‐uPA) by the cysteine protease cathepsin L

FEBS Letters

Mann, Karlheinz²  Goretzki, Lothar³  Calvete, Juan²  Graeff, Henner³  Schmitt, Manfred³  Günzler, Wolfgang A.¹  Chucholowski, Nicolaus³  Jänicke, Fritz³  Kramer, Michael⁴ 

[1] Grünenthal GmbH, D-5190 Stolberg, Germany;Max-Planck-Institut für Biochemie, D-8033 Martinsried bei München, Germany;Frauenklinik der Technischen Universität München, Klinikum rechts der Isar, D-8000 München 80, Germany;Institut für Immunologie, Universität Heidelberg, D-6900 Heidelberg, Germany

关键词: Pro-uPA;    Urokinase;    Cysteine protease;    Cathepsin B;    Cathepsin L;    N-Terminal amino acid sequence analysis;    BSA;    bovine serum albumin;    GFD;    growth factor-like domain;    E-64;    trans-epoxysuccinyl-L-leucylamino-(guanidino)-butane;    HPLC;    high-performance liquid chromatography;    HMW-uPA;    high molecular weight form of uPA;    mab;    monoclonal antibody;    pro-uPA;    proenzyme form of uPA (enzymatically inactive);    uPA;    urokinase-type plasminogen activator;   

DOI  :  10.1016/0014-5793(92)80339-I

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Increased levels of both the cysteine protease, cathepsin L, and the serine protease, uPA (urokinase-type plasminogen activator), are present in solid tumors and are correlated with malignancy. uPA is released by tumor cells as an inactive single-chain proenzyme (pro-uPA) which has to be activated by proteolytic cleavage. We analyzed in detail the action of the cysteine protease, cathepsin L, on recombinant human pro-uPA. Enzymatic assays, SDS-PAGE and Western blot analysis revealed that cathepsin L is a potent activator of pro-uPA. As determined by N-terminal amino acid sequence analysis, activation of pro-uPA by cathepsin L is achieved by cleavage or the Lys¹⁵⁸-lle¹⁵⁹ peptide bond, a common activation site of serine proteases such as plasmin and kallikrein. Similar to cathepsin B (Kobayashi et al., J. Biol. Chem. (1991) 266, 5147-5152) cleavage of pro-uPA by cathepsin L was most effective at acidic pH (molar ratio of cathepsin L to pro-uPA of 1:2,000). Nevertheless, even at pH 7.0, pro-uPA was activated by cathepsin L, although a 10-fold higher concentration of cathepsin L was required. As tumor cells may produce both pro-uPA and cathepsin L, implications for the activation of tumor cell-derived pro-uPA by cathepsin L may be considered. Different pathways activation of pro-uPA in tumor tissues may coexist: (i) autocatalytic intrinsic activation of pro-uPA; (ii) activation by serine proteases (plasmin, kallikrein. Factor XIIa); and (iii) activation by cysteine proteases (cathepsin B and L).

【 授权许可】

Unknown