Protein modification by methylglyoxal: chemical nature and synthetic mechanism of a major fluorescent adduct.

The nonenzymatic Maillard reaction of proteins, initiated by the addition of sugars and other aldehydes and ketones, is thought to be an important mechanism in aging and the pathogenesis of diabetic complications. The alpha-dicarbonyl compounds are considered to be key intermediates in this reaction. Methylglyoxal (MG) (pyruvaldehyde), a physiological alpha-dicarbonyl compound, has been shown to modify proteins both in vitro and in vivo.

Protein cross-linking by the Maillard reaction. Isolation, characterization, and in vivo detection of a lysine-lysine cross-link derived from methylglyoxal.

The Maillard reaction, initiated by nonenzymatic glycosylation of amino groups on proteins by reducing sugars, has been studied for its potential role in aging and the complications of diabetes. One of the major consequences of the advanced Maillard reaction in proteins is the formation of covalently cross-linked aggregates. The chemical nature of the cross-linking structures is largely unknown.

Heat treatment of Corynebacterium ammoniagenes leads to aeration dependent accumulation of 2-C-methyl-D-erythritol-2,4-cyclopyrophosphate.

2-C-methyl-D-erythritol-2,4-cyclopyrophosphate (MEC) identified as a new bacterial oxidative stress substance (Ostrovsky D. et al. (1993) Biochem.

1H and 13C NMR study of the molecular interaction mechanism between chloramphenicol and human serum albumin.

Molecular mechanism of the interaction between human serum albumin and cloramphenicol was studied by 1H and 13C NMR-spectroscopy. It was found that the main role belongs to [formula: see text] groups of chloramphenicol. A schematic model of the complex-formation between serum albumin and chloramphenicol was proposed.

Bacterial oxidative stress substance spontaneously recyclizes to form 2-methylbutane-1,2,3,4-tetraol-1,2-cyclophospho-4-phosphate.

The cells of Corynebacterium (Brevibacterium) ammonia-genes cultivated in a medium supplemented with diquat or benzylviologen accumulate 2-methylbutane-1,2,3,4-tetraol-2,4- cyclopyrophosphate as revealed by 31P-NMR spectroscopy. On heating at 120 degrees C for 30 min the cells still maintain a substantial portion of this compound and acquire new cyclic phosphates characterized by 31P-NMR chemical shifts of +17.3 and +20 p.