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Triosidines: novel Maillard reaction products and cross-links from the reaction of triose sugars with lysine and arginine residues.

ABSTRACT: The role of the highly reactive triose sugars glyceraldehyde and glyceraldehyde-3-phosphate in protein cross-linking and other amino acid modifications during the Maillard reaction was investigated. From the incubation of glyceraldehyde with N (alpha)-acetyl-L-lysine and N (alpha)-acetyl-L-arginine, we isolated four new Maillard reaction pyridinium compounds named 'triosidines'. Two of them, 'lys-hydroxy-triosidine' [1-(5-amino-5-carboxypentyl)-3-[(5-amino-5-carboxypentylamino)methyl]-5-hydroxypyridinium] and 'arg-hydroxy-triosidine' [2-(4-amino-4-carboxybutylamino)-8-(5-amino-5-carboxypentyl)-6-hydroxy-3,4-dihydro-pyrido[2,3-d]pyrimidin-8-ium] are fluorescent, UV-active Lys-Lys and Lys-Arg cross-links respectively. Their structures were identified by NMR and MS. In addition, two UV-active lysine adducts, 'trihydroxy-triosidine' [1-(5-amino-5-carboxypentyl)-3,4-dihydroxy-5-(hydroxymethyl)pyridinium] and 'triosidine carbaldehyde' [1-(5-amino-5-carboxypentyl)-3-formylpyridinium] were tentatively identified by MS. All structures involve six sugar-derived carbons as part of the heterocyclic ring. Of the two novel cross-links, only arg-hydroxy-triosidine was formed by glyceraldehyde-3-phosphate, an intermediate metabolite of the glycolytic pathway. Lys-hydroxy-triosidine and arg-hydroxy-triosidine were detected in human and porcine corneas treated with glyceraldehyde. The HPLC-fluorescence identification was confirmed by MS. Triosidines were also formed from dihydroxyacetone, a widely used artificial sun-tanning agent. Triosidines are expected to be useful tools in tissue engineering, where the utilization of highly reactive sugars is needed to stabilize the loose matrix. In addition, they are expected to be present in selected biological conditions, such as on consumption of a high fructose diet, and syndromes associated with high glyceraldehyde excretion, such as Fanconi Syndrome, fructose-1,6-diphosphatase deficiency and tyrosinaemia.

SUBMITTER: Tessier FJ

PROVIDER: S-EPMC1223106 | biostudies-other | 2003 Feb

REPOSITORIES: biostudies-other

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Project description:Glucose-lysine based Maillard reaction products (MRPs) are introduced to the human body via food ingestion or are synthesized in vivo. Depending on reaction conditions, they represent a mixture of compounds with diverse chemical structures and physiological properties. MRPs may also be a potential nutrient source for Salmonella, a major foodborne gastrointestinal pathogen. This study was designed to determine the growth and transcriptional responses of S. Typhimurium LT2 to MRPs generated at low water activity to simulate the reaction occurring during food processing and storage. Maillard reactions between N-Î±-acetyl-lysine and glucose were varied in time (4, 23, and 143 h) to generate sub-samples with prevailing Amadori compound, advanced glycation end products (AGEs), or melanoidines respectively. The addition of MRP up to 5 mg mL-1 to defined media with 0.4% glucose had no effect on S. Typhimurium LT2 growth. In media, where the MRP sub-samples (4 and 23 h) served as the only carbon source, MRP assimilation by S. Typhimurium LT2 was observed as secondary logarithmic growth phases (0.063 h-1 and 0.072 h-1) after the growth on glucose available in the MRP reaction mixtures (0.479 h-1). The MRPs sub-sample with the highest concentration of melanoidines (143 h) also supported S. Typhimurium LT2 growth (0.368 h-1). Of the three MRPs sub-samples, the Amadori compound was the preferred carbon source for S. Typhimurium LT2 as evidenced by its almost complete disappearance (98%). Decreases in AGEs (37%) and melanoidines (15%), when incubated with S. Typhimurium LT2, also occurred. Transcription profiles of the cells grown on the MRPs fractions revealed predominant up-regulation of genes associated with the functional groups of energy metabolism, fatty and phospholipid metabolism, cellular process, and regulatory functions, and general down-regulation of the genes in the groups of amino acid biosynthesis, protein synthesis and transcription, transport and binding proteins, and DNA metabolism. The carbon flow in tricarboxylic acid (TCA) cycle partitioned by the glyoxylate cycle appeared to play an essential role in the assimilation of glucose-lysine-derived MRPs. The high expression level of numerous genes encoding hypothetical proteins or proteins with unknown function suggested the presence of genes whose role in glucose-lysine MRPs catabolism in Salmonella remains to be determined. This study was designed to determine the growth and transcriptional responses of S. Typhimurium LT2 to MRPs generated at low water activity to simulate the reaction occurring during food processing and storage. Maillard reactions between N-Î±-acetyl-lysine and glucose were varied in time (4, 23, and 143 h) to generate sub-samples with prevailing Amadori compound, advanced glycation end products (AGEs), or melanoidines respectively. Total bacterial RNA was isolated as previously described and the RNA samples were then converted to fluorescently-labeled cDNA and hybridized to S. Typhimurium microarrays version 5 (NIAID's Pathogen Functional Genomics Resource Center). Real-time PCR and physiological experiments were performed to validate the microarray data. In all supplementary files channel A = Cy3, channel B = Cy5.

Project description:Glucose-lysine based Maillard reaction products (MRPs) are introduced to the human body via food ingestion or are synthesized in vivo. Depending on reaction conditions, they represent a mixture of compounds with diverse chemical structures and physiological properties. MRPs may also be a potential nutrient source for Salmonella, a major foodborne gastrointestinal pathogen. This study was designed to determine the growth and transcriptional responses of S. Typhimurium LT2 to MRPs generated at low water activity to simulate the reaction occurring during food processing and storage. Maillard reactions between N-α-acetyl-lysine and glucose were varied in time (4, 23, and 143 h) to generate sub-samples with prevailing Amadori compound, advanced glycation end products (AGEs), or melanoidines respectively. The addition of MRP up to 5 mg mL-1 to defined media with 0.4% glucose had no effect on S. Typhimurium LT2 growth. In media, where the MRP sub-samples (4 and 23 h) served as the only carbon source, MRP assimilation by S. Typhimurium LT2 was observed as secondary logarithmic growth phases (0.063 h-1 and 0.072 h-1) after the growth on glucose available in the MRP reaction mixtures (0.479 h-1). The MRPs sub-sample with the highest concentration of melanoidines (143 h) also supported S. Typhimurium LT2 growth (0.368 h-1). Of the three MRPs sub-samples, the Amadori compound was the preferred carbon source for S. Typhimurium LT2 as evidenced by its almost complete disappearance (98%). Decreases in AGEs (37%) and melanoidines (15%), when incubated with S. Typhimurium LT2, also occurred. Transcription profiles of the cells grown on the MRPs fractions revealed predominant up-regulation of genes associated with the functional groups of energy metabolism, fatty and phospholipid metabolism, cellular process, and regulatory functions, and general down-regulation of the genes in the groups of amino acid biosynthesis, protein synthesis and transcription, transport and binding proteins, and DNA metabolism. The carbon flow in tricarboxylic acid (TCA) cycle partitioned by the glyoxylate cycle appeared to play an essential role in the assimilation of glucose-lysine-derived MRPs. The high expression level of numerous genes encoding hypothetical proteins or proteins with unknown function suggested the presence of genes whose role in glucose-lysine MRPs catabolism in Salmonella remains to be determined.

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Triosidines: novel Maillard reaction products and cross-links from the reaction of triose sugars with lysine and arginine residues.

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