title: Nonenzymatic glycation of human platelet membrane proteins in vitro and in vivo.
abstract: Human platelet membrane proteins (PMP), incubated in vitro in the presence of various concentrations of glucose, undergo nonenzymatic glycation, as evidenced by incorporation of [3-3H]glucose radioactivity into the acid-precipitable fraction. The time course of the reaction is linear for the first hours, and the rate of glycation depends on the glucose concentration in the medium: at a glucose concentration of 80 mmol/L, up to 60 nmol of glucose is bound per milligram of PMP. The ketoaminic nature of the glucose/protein linkages was demonstrated by the finding of 5-hydroxymethylfurfuraldehyde by liquid-chromatographic analysis of acid hydrolysates of PMP. We analyzed PMP from 13 subjects with type I poorly controlled diabetes and from 10 nondiabetics. Nonenzymatic glycation, evaluated as nanomoles of the aldehyde per milligram of protein, was much greater in diabetic patients than in nondiabetics: 1.58 +/- 0.70 vs 0.37 +/- 0.18 (mean +/- SD).
mesh_terms: D001792:Blood Platelets / Q000378:metabolism*; D002458:Cell Fractionation; D002853:Chromatography, Liquid; D003922:Diabetes Mellitus, Type 1 / Q000097:blood*; D005662:Furaldehyde / Q000031:analogs & derivatives / Q000032:analysis; D005947:Glucose / Q000378:metabolism*; D006801:Humans; D066298:In Vitro Techniques; D008565:Membrane Proteins / Q000378:metabolism*
chemical_list: D008565:Membrane Proteins; C008046:5-hydroxymethylfurfural; D005662:Furaldehyde; D005947:Glucose