Glycoproteins from the aorta

Abstract

This review deals with the data on isolation techniques, structure, physicochemical properties and biological function of glycoproteins isolated from the aorta. Some glycoproteins extracted at low ionic strengths (soluble glycoproteins) are immunologically distinct from serum glycoproteins. The designation "structural glycoprotein" was proposed for glycoproteins associated with the collagen elastin matrix. These glycoproteins are solubilized by dissociative and reducing buffers. A selective hydrolysis of the insoluble collagen prior to their extraction was also reported. The molecular weights are in the range of 53 - 72.000 and 35.000 - 27.000 daltons for the soluble and the structural glycoproteins respectively. The aorta glycoproteins are rich in polar aminoacids. The primary structure of glycoproteins from aorta is not yet established. The electrophoretic mobility and sugar content of some glycoproteins extracted at low ionic forces change with the maturation and sex. The biosynthesis of a soluble glycoprotein (glycoprotein B) and of structural glycoproteins by aortic smooth muscle cells was demonstrated "in vitro". The structural glycoproteins appear as microfibrillae in electron microscopy. Their self-aggregation may be due to hydrophobic interactions. The association of microfibrillar glycoprotein with elastin in connective tissues and in the culture medium of aortic smooth muscle cells suggests the role of glycoprotein-elastin interactions in morphogenesis.