Journal ArticleDOI
Sugar-mediated crosslinking of alpha-biotinylated-Lys to cysteamine-agarose support: a method to isolate Maillard Lys-Lys-like crosslinks.
TLDR
This work reports here a simple approach that allows the preparation and isolation of milligram quantities of sugar-mediated AGE Lys-Lys-like crosslinks from glycation mixtures, and fractionation of these preparations over a monomeric avidin column afforded a complete separation of cane sugar modifications and the crosslinks.Abstract:
Advanced glycation end products (AGEs) and, specifically, protein-protein AGE crosslinks have long been studied for their potential role in aging, diabetic complications and Alzheimer disease. With few exceptions, the chemical nature of these structures remains unknown. We report here a simple approach that allows the preparation and isolation of milligram quantities of sugar-mediated AGE Lys-Lys-like crosslinks from glycation mixtures. The method is based on a sugar-dependent incorporation of Nα-biotinyl-l-Lys into cysteaminyldisulfide Sepharose 6B (AE-S-S-Sepharose 6B). Glycation mixtures with six different sugars showed a time- and sugar-dependent decrease in the concentration of the support-bound primary amino groups and accounted for almost 90% loss of cysteaminyl amino groups at the end of the various incubation periods. 4-Hydroxyazobenzene-2-carboxylic acid-avidin assays indicated the incorporation of Nα-biotinyl-l-Lys equal to 8% of the total support amino groups with methylglyoxal after 7d and 1% with fructose and glucose after 1 mo of incubation. Treatment of the washed, sugar-modified supports with 2-mercaptoethanol released the bulk of the bound AGE modifications and the crosslinks. Subsequent fractionation of these preparations over a monomeric avidin column afforded a complete separation of sugar-mediated AGE modifications and the crosslinks. Depending on the sugar employed, micromolar amounts of biotinylated Lys-Lys-like crosslinks were generated by this two-step procedure from 8 mL of the original AE-S-S-Sepharose 6B.read more
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Journal ArticleDOI
Involvement of Maillard reactions in Alzheimer disease.
TL;DR: The chemistry and biochemistry of AGE-related crosslinks such as pyrraline, pentosidine, carboxymethyllysine (CML), crosslines, imidazolidinones, and dilysine crosslinks (GOLD and MOLD), as well as their possible involvement in neurodegenerative conditions are discussed.
Journal ArticleDOI
Convenient supported recyclable material based on dihydrolipoyl-residue for the reduction of disulfide derivatives
TL;DR: In this paper, a quantitative method for the reduction of disulfides, which uses a totally recyclable solid phase supported reducing agent, is reported, using a highly stable 100% PEG Aminomethyl-ChemMatrix® resin that can swell in aqueous media and in organic solvents.
References
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Tissue sulfhydryl groups
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An improved 2,4,6-trinitrobenzenesulfonic acid method for the determination of amines.
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Journal ArticleDOI
Accelerated age-related browning of human collagen in diabetes mellitus
TL;DR: Collagen adducts from aged and diabetic individuals had absorption and fluorescence spectra identical to those of collagen samples that underwent nonenzymatic browning with glucose in vitro, suggesting their likely occurrence throughout the body could explain the correlation between arterial stiffening, decreased joint mobility, and the severity of microvascular complications in type I diabetics.