In vitro non-enzymatic glycation and formation of browning products in the bovine lens alpha-crystallin.
Calf lens LMW alpha-crystallin was glycated by incubating with various sugars (glucose, glucose-6-P and ribose) for 21 days. All sugars induced disulfide formation, but ribose also produced higher molecular weight cross-linked species. The ribocated protein turned yellow in color and had a strong blue fluorescence (Ex/Em = 370/450 nm) typical for a browning product. The chromophore of the browning product showed a new circular dichroism (CD) band at 320-330 nm. Conformational study indicated that the browning reaction destablized protein and may play a significant role in protein aggregation and insolubilization.
Liang
J N
JN
Howe Laboratory of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston 02114.
Rossi
M T
MT
D000818:Animals; D002417:Cattle; D002942:Circular Dichroism; D003459:Crystallins; D004591:Electrophoresis, Polyacrylamide Gel; D005947:Glucose / Q000494:pharmacology*; D019298:Glucose-6-Phosphate; D005958:Glucosephosphates / Q000494:pharmacology*; D066298:In Vitro Techniques; D015416:Maillard Reaction; D008970:Molecular Weight; D011487:Protein Conformation / Q000187:drug effects; D011489:Protein Denaturation / Q000187:drug effects; D012266:Ribose / Q000494:pharmacology*; D013050:Spectrometry, Fluorescence; D014508:Urea
D003459:Crystallins; D005958:Glucosephosphates; D019298:Glucose-6-Phosphate; D012266:Ribose; D014508:Urea; D005947:Glucose