Intermolecular reducible cross-links in rat glomerular basement membrane.
Glomerular basement membrane (GBM) was purified from adult rats and treated with tritiated borohydride for analysis of the reducible cross-links. After acid hydrolysis, samples were subjected, with and without prior gel filtration on Biogel P-2, to a chromatographic system standardized with known cross-links. The major peak of radioactivity co-eluted with authentic di-hydroxylysinonorleucine (di-OHLNL) standard. Derivation of this cross-link from lysine was corroborated by demonstrating its presence in GBM purified after incubation of isolated glomeruli with [14c]-lysine and after in vivo injection of [14C]-lysine. GBM labeled in vitro with radioactive lysine also contained peaks co-eluting with hydroxylysinonorleucine and lysinonorleucine standards, as well as at unidentified positions in the chromatogram. The findings indicate that rat GBM contains lysine-derived cross-links, of which di-OHLNL is the major reduced form.
D000596:Amino Acids / Q000032:analysis; D000818:Animals; D001485:Basement Membrane / Q000032:analysis*; D002250:Carbon Radioisotopes; D003094:Collagen / Q000032:analysis*; D066298:In Vitro Techniques; D007678:Kidney Glomerulus / Q000033:anatomy & histology*; D008297:Male; D051381:Rats
D000596:Amino Acids; D002250:Carbon Radioisotopes; D003094:Collagen