Abstract
Glomeruli were separated and purified from the bovine renal cortex by pressing through and filtering with sieves of varing mesh. Glomerular basement membrane obtained from this by sonication was proved to be free from cellular components.
The protein of the glomerular basement membrane was characterized by a high content of glycine, hydroxyproline, proline and glutamic acid;a high hydroxylation rate of lysine and proline; and an occurrence of 3-hydroxyproline and half-cystine.
In collagen extracted from the glomerular basement membrane, glycine, histidine, valine, methionine, tyrosine and imino acids contained almost the same amount of those in interstitial collagen, while hydroxylysine was significantly high and the hydroxylation of lysine and proline was predominant. The amount of 3-hydroxyproline was substantial; alanine was significantly low; and half-cyst meproved to be present in small amounts.
Glucose contained the same amount of galactose in both of the glomerular basement membrane (approximately 2%) and collagen (approximately 5%), and th ratio of galactose to glucose was 1.03 in the glomerular basement membrane and 1.07 in collagen.
Acrylamide gel electrophoresis showed two distinct and two faintly stained bands: the first two migrated individually a little later than 13 and a chain of interstitial collagen and the other was faster than a chain. All of the four bands were positive to periodic acid-Schiff stain for carbohydrates.
Two-dimensional electrophoresis on cellulose acetate strips showed that most of mucopolysaccharide in the glomerular basement membrane was composed of heparan sulfate, but hyaluronic acid, dermatan sulfate and chondroitin sulfate were also recognized.
