Diabetes, Vol 34, Issue 9 938-941, Copyright © 1985 by American Diabetes Association
Nonenzymatic glycosylation products on collagen covalently trap low-density lipoprotein
M Brownlee, H Vlassara and A Cerami
Advanced nonenzymatic glycosylation products capable of cross-linking
proteins accumulate on collagen in vivo in proportion to time-averaged
blood glucose concentration. In this report, we have evaluated the ability
of advanced nonenzymatic glycosylation products formed on collagen in vitro
to covalently bind low-density lipoprotein (LDL) in a manner similar to
that which occurs in human atherosclerotic lesions. At constant LDL
concentration, covalent trapping increased linearly with the extent of
advanced glycosylation product formation, from 1.42 +/- 0.15 to 4.46 +/-
0.36 micrograms LDL protein/mg collagen. At a constant level of collagen
advanced glycosylation product, LDL binding increased as a function of
increasing LDL concentration. At an LDL-cholesterol level of 103 mg/dl,
covalent trapping of LDL by nonenzymatic glycosylation products on collagen
averaged 3.2 times as much as control (P less than 0.01). These data
indicate that LDL is bound specifically by reactive products generated by
nonenzymatic glycosylation of collagen, and suggest that excessive LDL
trapping by hyperglycemia-induced advanced glycosylation endproducts may
contribute to the accelerated development of atherosclerosis in patients
with diabetes mellitus.