Effect of individual caseins on plasminogen activation by bovine urokinase-type and tissue-type plasminogen activators.
The effect was examined of individual caseins on the rate of plasminogen activation by bovine urokinase-type and tissue-type plasminogen activators. All individual caseins (alpha-CN, beta-CN, and kappa-CN) enhanced the activity of both types of plasminogen activators. Optimal concentrations for alpha-CN and beta-CN were 5 and 25 micrograms/ml, respectively. The enhancement of enzymatic activity declined when concentrations of alpha-CN and beta-CN were higher. In contrast, increasing concentrations of kappa-CN from 0 to 200 micrograms/ml resulted in corresponding increases in activity of both types of plasminogen activators. On a weight basis, alpha-CN was the most effective enhancer of plasminogen activator activity. Indirect evidence obtained with experiments utilizing alpha-CN immobilized on agarose suggested that the effect is related to extensive binding of plasminogen and both types of plasminogen activators to casein.
Politis
I
I
Department of Animal and Food Sciences, University of Vermont, Burlington 05405, USA.
White
J H
JH
Zavizion
B
B
Goldberg
J J
JJ
Guo
M R
MR
Kindstedt
P
P
D000595:Amino Acid Sequence; D000818:Animals; D002364:Caseins / Q000494:pharmacology*; D002417:Cattle; D002863:Chromogenic Compounds; D004591:Electrophoresis, Polyacrylamide Gel; D005341:Fibrinolysin / Q000378:metabolism; D008969:Molecular Sequence Data; D009842:Oligopeptides / Q000378:metabolism; D010958:Plasminogen / Q000378:metabolism*; D010959:Tissue Plasminogen Activator / Q000494:pharmacology*; D014568:Urokinase-Type Plasminogen Activator / Q000494:pharmacology*
D002364:Caseins; D002863:Chromogenic Compounds; D009842:Oligopeptides; C018788:valyl-leucyl-lysine 4-nitroanilide; D010958:Plasminogen; D010959:Tissue Plasminogen Activator; D005341:Fibrinolysin; D014568:Urokinase-Type Plasminogen Activator