Chemical Structure of Tubular and Glomerular Basement Membranes of Human Kidney

Enzymatic digestion with pronase and collagenase of glomerular and tubular basement membranes isolated from human kidneys yields soluble glycopeptides which can be separated by gel filtration and ion exchange chromatography. Two different glycopeptides were isolated from both types of membranes. One contains a disaccharide composed of an equimolecular quantity of glucose and galactose probably linked to hydroxylysine. The second contains a heterosaccharide composed of galactose, fucose, mannose, hexosamine and sialic acids. The heterosaccharide from glomerular basement membrane had a molecular weight of 3600 and twice as much sialic acid as the heterosaccharide from tubular basement membrane which had a molecular weight of 3400.