Inhibition of plasmin activity by sulfated polyvinylalcohol-acrylate copolymers.
The effect of four sulfated polyvinylalcohol-acrylate copolymers and heparin on plasminogen activation and on plasmin activity is studied. The molecules differing in charge (proportion of negatively charged units 40.5%-73.5% of the total) and in size (5600 Da-8800 Da) accelerate plasminogen activation by 2- up to 4-fold at a 7-fold molar excess of the polyvinylacrylates over plasminogen. They, however, exert a concentration and charge-dependent effect on plasmin: both the amidolytic (half-maximal effect at a 1.33-3.66 molar excess of the polyvinylacrylates) and fibrinolytic (half-maximal effect at 1.23-1.72 molar excess of the polyvinylacrylates) activities of plasmin are inhibited. In contrast, heparin (a similarly carboxylated and sulfated polymer) and polyvinylacrylates with a low number of sulfate groups (30% sulfated monomers) at concentrations up to 2.2 microM do not affect plasminogen activation and plasmin activity in a milieu of physiological ionic strength. Experiments with plasmin derivatives lacking N-terminal peptides of different length (des-kringle(1-4) and des-kringle(1-5) plasmin) show identical changes in the protease activities, precluding involvement of the kringle-domain in the interaction with the polyvinylacrylates. Fluorescence studies evidence the charge-dependent binding of the polyvinylacrylates to plasmin, but not to plasminogen. Thus, through non-covalent interaction with the protease-domain of plasmin the polyvinylacrylates inhibit fibrinolysis. Since these sulfated copolymers inhibit both thrombin [4] and plasmin activity, they may be a useful therapeutic tool in situations when both the blood coagulation and the fibrinolytic system are activated (such as intravascular coagulation and fibrinolysis, ICF).
Vörös
G
G
Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary.
Kolev
K
K
Csomor
K
K
Machovich
R
R
D000180:Acrylic Resins / Q000494:pharmacology*; D000925:Anticoagulants / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation / Q000187:drug effects; D005341:Fibrinolysin / Q000037:antagonists & inhibitors*; D005342:Fibrinolysis / Q000187:drug effects; D005343:Fibrinolytic Agents; D006493:Heparin / Q000494:pharmacology; D006801:Humans; D007700:Kinetics; D010446:Peptide Fragments / Q000037:antagonists & inhibitors / Q000378:metabolism; D010958:Plasminogen / Q000037:antagonists & inhibitors / Q000378:metabolism; D013050:Spectrometry, Fluorescence
D000180:Acrylic Resins; D000925:Anticoagulants; D005343:Fibrinolytic Agents; D010446:Peptide Fragments; C018998:lysyl-plasminogen; C063252:sulfated acrylic acid-vinyl alcohol copolymer; D010958:Plasminogen; D006493:Heparin; D005341:Fibrinolysin