Inhibition of Hageman Factor,Plasma Thromboplastin Antecedent,Thrombin and Other Clotting Factors by Phenylglyoxal Hydrate 1

Abstract

Summary

Exposure of purifed Hageman factor (HF, Factor XII) to phenylglyoxal hydrate (PGH), an agent reacting with argi-nine residues in protein, inhibited its coagulant properties upon subsequent exposure of negatively charged agents. Once HF had been exposed to kaolin or ellagic acid, however, subsequent addition of PGH was much less inhibitory. PGH had no effect upon the ability of HF to bind to negatively charged surfaces. PGH also inhibited preparations of activated PTA (Factor XI) and thrombin, and, when incubated with plasma, reduced the titer of coagulable fibrinogen, PTA, Christmas factor (Factor IX), antihemo-philic factor (Factor VIII), Factor VII, Stuart factor (Factor X), proaccelerin (Factor V) and prothrombin (Factor II), and to a lesser degree, HF.

Nancy Barstow provided invaluable assistance.