2-Ammonio-6-(3-oxidopyridinium-1-yl)hexanoate (OP-lysine) Is a Newly Identified Advanced Glycation End Product in Cataractous and Aged Human Lenses
| Autor: | Ognyan K. Argirov, Bin Lin, Beryl J. Ortwerth |
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| Rok vydání: | 2004 |
| Předmět: |
Glycation End Products
Advanced Aging Magnetic Resonance Spectroscopy Time Factors Light Ultraviolet Rays Lysine Pyridinium Compounds Ascorbic Acid complex mixtures Biochemistry High-performance liquid chromatography Cataract Hydrolysate chemistry.chemical_compound Glycation Glyceraldehyde Lens Crystalline Humans Caproates Molecular Biology Chromatography High Pressure Liquid Aged chemistry.chemical_classification Glycolaldehyde Chromatography Hydrolysis Water Cell Biology Middle Aged Chromatography Ion Exchange Amino acid Models Chemical chemistry bacteria Advanced glycation end-product |
| Zdroj: | Journal of Biological Chemistry. 279:6487-6495 |
| ISSN: | 0021-9258 |
| Popis: | Post-translational modifications of proteins take place during the aging of human lens. The present study describes a newly isolated glycation product of lysine, which was found in the human lens. Cataractous and aged human lenses were hydrolyzed and fractionated using reverse-phase and ion-exchange high performance liquid chromatography (HPLC). One of the nonproteinogenic amino acid components of the hydrolysates was identified as a 3-hydroxypyridinium derivative of lysine, 2-ammonio-6-(3-oxidopyridinium-1-yl)hexanoate (OP-lysine). The compound was synthesized independently from 3-hydroxypyridine and methyl 2-[(tert-butoxycarbonyl)amino]-6-iodohexanoate. The spectral and chromatographic properties of the synthetic OP-lysine and the substance isolated from hydrolyzed lenses were identical. HPLC analysis showed that the amounts of OP-lysine were higher in water-insoluble compared with water-soluble proteins and was higher in a pool of cataractous lenses compared with normal aged lenses, reaching 500 pmol/mg protein. The model incubations showed that an anaerobic reaction mixture of Nalpha-tert-butoxycarbonyllysine, glycolaldehyde, and glyceraldehyde could produce the Nalpha-t-butoxycarbonyl derivative of OP-lysine. The irradiation of OP-lysine with UVA under anaerobic conditions in the presence of ascorbate led to a photochemical bleaching of this compound. Our results argue that OP-lysine is a newly identified glycation product of lysine in the lens. It is a marker of aging and pathology of the lens, and its formation could be considered as a potential cataract risk-factor based on its concentration and its photochemical properties. |
| Databáze: | OpenAIRE |
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