Distribution of non-enzymatically bound glucose in in vivo and in vitro glycosylated type I collagen molecules.

Non-enzymatic glycosylation of collagen occurs both in vivo during diabetes and in vitro after incubation with glucose. Glycosylated collagen exhibits altered physicochemical and biological properties which could explain some of the complications of diabetes. To provide a mechanistic explanation of this modification the localization of bound glucose was investigated using NaB[3H]H4 reduction and CNBr cleavage. Glucose fixation is distributed mainly on the alpha 1CB6 peptide after in vitro glycosylation whereas this distribution occurs less specifically during diabetes. It is concluded that fibrillogenesis alteration of in vitro glycosylated collagen is related to glucose fixation on free epsilon NH2 sites normally implied in intermolecular interactions.