Structure and In Vivo Behavior of Human Fibrinogen Fragment-D 1

Abstract

Summary

Polyacrylamide gel disc electrophoresis has been used to determine molecular weights of fg-D and its three subunits. A molecular weight of 78,800 ± 3900 was determined for fg-D. Three subunits, apparently representing individual polypeptide chains with molecular weights of 44,000 ± 2700; 25,350 ± 900; and 10,400 ± 720 have been demonstrated. The sum of the molecular weights of these polypeptide chains agrees closely with the estimated size of the intact fg-D fragment. We have confirmed micro-heterogeneity of fg-D on disc acrylamide gel electrophoresis and have demonstrated that this heterogeneity is a reflection of charge isomerization and does not represent detectable differences in size. In vivo studies demonstrated that fg-D does not interact with plasma proteins but circulates in a free state. It is cleared rapidly from plasma with a half-life of 2 hr ± 12 min, and excreted in urine following catabolic degradation.

We would like to acknowledge the continued interest and encouragement of Dr. Kenneth Moser (University of California, San Diego). Discussing of this work with Dr. Edward Plow was most helpful; and assistance in manuscript preparation by Mrs. Cleo-Mae Mrozek is appreciated.