Functional Consequences of Differences in Carbohydrate Sequences of Fetal and Adult Plasminogen and Fibrinogen

Abstract

The fibrinolytic system is involved in a wide variety of biological phenomena such as dissolution of fibrin blood clots, tissue remodeling, metastasis, angiogenesis, wound healing, embryogenesis, and embryo implantation [1]. The absolute and relative concentrations of various components of the fibrinolytic system in neonates differ from adults, and they are dependent on both the gestational age and postnatal age [for review see 2]. In addition, the functional behavior of fetal plasminogen and fetal fibrinogen differ from the adult forms, although electrophoretic molecular weight analyses, as well as amino-acid composition and partial aminoacid sequencing, revealed no differences between fibrinogen and the plasminogen forms 1 and 2 of neonates and adults [3–12]. Therefore, variations in functional behavior have been related to differences in carbohydrate composition [5]. Oligosaccharides linked to proteins may contribute to receptor-mediated interactions, protein stability, clearance from the circulation, and physiological function [13, 14].