Protein-formaldehyde reactions effects

This process of cross-linking does not appear have a major effect on protein secondary structure at room temperature. However, cross-links formed by reactions of formaldehyde with proteins retard, but do not eliminate, protein denaturation that occurs when proteins are heated to a temperature of approximately 70°C or above.7... 

Cause of denaturation. Many hypotheses have been proposed to explain the denaturation of muscle proteins (9-17). These hypotheses include 1) the effects of inorganic salts concentrated into the liquid phase of the frozen system 2) water-activity relations 3) reactions with lipids 4) reaction with formaldehyde derived from trimethyl amine (in fish) 5) auto-oxidation ... 

The activity of EtO, similar to many other disinfectants, preservative, and sterilizing agents, such as formaldehyde, beta-propiolactone, methylbromide, and ethylenimine, depends on an alkylation reaction. This reaction occurs with some groups within the complex enzymes, proteins, and nucleic acids in the bacterial cell. These compounds can then no longer be effective or necessary to the vital processes of the microorganism cell. Furthermore, one would expect these effects to vary according to the extensions of reactions static, mutagenic, or toxic. 

Ogura K, Fujita M, lida H (1980) A two-phase reaction catalyzed by a protein. Asymmetric oxidation of formaldehyde dithioacetals with aqueous sodium metaperiodate. Tetrahedron Lett 21 2233-2236 Ohnishi Y, Kagami M, Ohno A (1975a) Reduction by a model of NAD(P)H. Effect of metal ion and stereochemistry on the reduction of a-keto esters by 1,4-dihydronicotinamide derivatives. J Am Chem Soc 97 4766-4768... 

Reaction of aldehydes with the indole NH group of tryptophan in proteins has been reported in tetanus toxin (251) and tobacco mosaic virus (26). In the latter instance, the Folin s phenol reagent color value decreased as the reaction with formaldehyde proceeded, and increased with removal of the aldehyde by dialysis in dilute acid. Indole, pure tryptophan, and glycyl tryptophan behaved in a similar manner, but not t3unsine nor glycyltyrosine. Benzaldehyde, acetaldehyde, propionalde-hyde, and butyraldehyde were also used in this work with similar effect. Reversal of formaldehyde inactivation of tobacco mosuc virus could not be confirmed (356). It was also claipaed that the drop in phenol color could not be correlated with a decrease in virus infectivity. 

Hexamethylenetetramine (E239), also known as urotropine, hexamine, methenamine or 1,3,5,7-tetraazaadamantane (8-57), arises as a reaction product of formaldehyde with ammonia. Its preservation effect appears to be due to the gradual liberation of formaldehyde (E240, which is not approved in the EU) and its oxidation product formic acid under acid conditions or in the presence of proteins. The most abundant end-product of formaldehyde in cheeses preserved with hexamethylenetetramine is spinacine, 4,5,5,7-tetrahydro-3//-imidazo[4,5-d]pyridine-6-carboxyhc acid (11-6), derived from the N-terminal histidine residue in y-casein. 

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