title: Comprehensive analysis of maillard protein modifications in human lenses: effect of age and cataract.
abstract: In human lens proteins, advanced glycation endproducts (AGEs) originate from the reaction of glycating agents, e.g., vitamin C and glucose. AGEs have been considered to play a significant role in lens aging and cataract formation. Although several AGEs have been detected in the human lens, the contribution of individual glycating agents to their formation remains unclear. A highly sensitive liquid chromatography-tandem mass spectrometry multimethod was developed that allowed us to quantitate 21 protein modifications in normal and cataractous lenses, respectively. N(6)-Carboxymethyl lysine, N(6)-carboxyethyl lysine, N(7)-carboxyethyl arginine, methylglyoxal hydroimidazolone 1, and N(6)-lactoyl lysine were found to be the major Maillard protein modifications among these AGEs. The novel vitamin C specific amide AGEs, N(6)-xylonyl and N(6)-lyxonyl lysine, but also AGEs from glyoxal were detected, albeit in minor quantities. Among the 21 modifications, AGEs from the Amadori product (derived from the reaction of glucose and lysine) and methylglyoxal were dominant.
authors: †Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/Saale, Germany.
authors: Mareen
authors: M
authors: Smuda
authors: †Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/Saale, Germany.
authors: Christian
authors: C
authors: Henning
authors: ‡Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, 2085 Adelbert Road, Cleveland, Ohio 44106, United States.
authors: Cibin T
authors: CT
authors: Raghavan
authors: §Iladevi Cataract and IOL Research Center, Gurukul Road, Memnagar, Ahmedabad, Gujarat 380052, India.
authors: Kaid
authors: K
authors: Johar
authors: §Iladevi Cataract and IOL Research Center, Gurukul Road, Memnagar, Ahmedabad, Gujarat 380052, India.
authors: Abhay R
authors: AR
authors: Vasavada
authors: ‡Department of Ophthalmology and Visual Sciences, Case Western Reserve University School of Medicine, 2085 Adelbert Road, Cleveland, Ohio 44106, United States.
authors: Ram H
authors: RH
authors: Nagaraj
authors: †Institute of Chemistry-Food Chemistry, Martin-Luther-University Halle-Wittenberg, 06120 Halle/Saale, Germany.
authors: Marcus A
authors: MA
authors: Glomb
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000378:metabolism* / Q000473:pathology; D002386:Cataract / Q000378:metabolism* / Q000473:pathology; D002648:Child; D005136:Eye Proteins / Q000378:metabolism*; D005260:Female; D017127:Glycation End Products, Advanced / Q000378:metabolism*; D006801:Humans; D015416:Maillard Reaction; D008875:Middle Aged; D011499:Protein Processing, Post-Translational
chemical_list: D005136:Eye Proteins; D017127:Glycation End Products, Advanced