Blood, 1954, Vol. 9, No. 5, pp. 513-519.
© 1954 American Society of Hematology, Inc.
The Effects of Tyrosinase on Certain Components of the
Blood Clotting System
EDITH J. KRUGELIS PH.D.1 and
IRWIN W. SIZER PH.D.1
1 Department of Biology, Massachusetts Institute of Technology, Cambridge,
Mass.
The clotting time of human and rat plasma was found to increase markedly
after exposure to mushroom tyrosinase. The main, but not exclusive, effect of
tyrosinase on the clotting system seems to be on fibrinogen, since the inactivating
effect of tyrosinase can be greatly reduced by the subsequent addition of excess
fibrinogen just before the clotting time of the plasma is measured. No evidence
was found for any major effect of tyrosinase on any of the other components of
plasma considered with the possible exception of prothrombin. Purified prothrombin is susceptible while prothrombin in plasma or serum is refractory to
tyrosinase.
Submitted on July 28, 1953
Accepted on September 1, 1953
