Malondialdehyde protein adducts

Lung, C. C. Fleisher, J. H. Meinke, G. Pinnas, J. L. Immunochemical properties of malondialdehyde-protein adducts. J. Immunol. Meth., 128 127-32. 1990. 

Inhibition of the formation of CML and pentosidine from various AGE precursors and BSA was more efficient with OPB-9195 than with AG.601 OPB-9195 also inhibited the formation of two ALEs (malondialdehyde-lysine and 4-hydroxynonenal-protein adduct) with an efficiency similar to that of AG. In glucose-based peritoneal dialysis fluid, OPB-9195 inhibited AGE formation, probably by trapping reactive carbonyls, such as GO, MGO, and 3-deoxyglucosone. 

Formation of hybrid adducts with acetaldehyde and malondialdehyde (MAA adducts) has been shown to act in a synergistic manner and may be involved in the stabilisation of protein adducts in vivo. Malondialdehyde (HOCH=CH-CHO) is a highly reactive dialdehyde originating from the non-enzymatic lipid peroxidation of a variety of unsaturated fatty acids. 

Kearley M.L., Patel A., Chien J., Tuma, D.J. Observation of a new nonfluorescent malondialdehyde-acetaldehyde-protein adduct by C NMR spectroscopy. Chemical Research in Toxicology, 12 100-105... 

Aldehydes, which are secondary products of lipid peroxidation, consist of other groups of agents involved in oxidative stress and modification of proteins structures. Protein cross-linking can occur in vitro employing the malondialdehyde (MDA) Schiff-base-type adducts produced by lysine residues. 

Willis MS, Klassen LW, Tuma DJ, Sorrell MF, Thiele GM (2002) Adduction of soluble proteins with malondialdehyde-acetaldehyde (MAA) induces antibody production and enhances T-cell proliferation. Alcohol Clin Exp Res, 26 94-106. 

The most popular method involves 2-thiobarbituric acid (TBA) two molecules of 2-thiobarbituric acid are condensed with malonaldehyde. The emergent chromogen — the two tautomeric structures of the red TBA-malonaldehyde adduct — is determined at 532 nm, and also often at 450 nm, to determine aUcenals and aUcanals, respectively. The qualitative Kreis test was based on a similar principle it involved detection of the epihydrine aldehyde — a tautomeric malondialdehyde — in a color reaction with resorcine or phloroglucinol. The popularity of the TBA test stems from a correlation between the results and sensory evaluations. Paradoxically, this is related to the most important drawback of the TBA technique — its lack of specificity. In addition to the reaction with malonaldehyde, TBA forms compounds of identical color with other aldehydes and ketones, products of aldehyde interaction with nitrogen compounds, and also with saccharides, ascorbic acid, creatine, creatinine, trimethylamine oxide, trimethylamine, proteins, and amino acids. For this reason, the TBA test may even be treated as a proteolysis indicator (Kolakowska and Deutry, 1983). Recently, TBA-reactive substances (TEARS) were introduced, primarily to stress that the reaction involves hydroperoxides in addition to aldehydes. Due to the nonspecificity of the TEARS test, its results reflect the rancidity of food better than other conventional methods, especially off-flavor, which is caused by volatiles from lipids as well as being affected by products of lipids interaction with nitrogenous compounds. 

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