Hemoglobin reaction with glyceraldehyde

Several different glycolytic intermediates such as glucose-6-phosphate, fructose-6-phosphate, fructose 1,6-diphosphate and glyceraldehyde-3-phosphate were proposed to serve as substrates. The direct reaction of hemoglobin with glucose is much slower and less specific than that with glucose-6-phosphate. 

The administration of TNT to laboratory animals leads to the excretion of 4-NHOH-DNT, 2-NH2-DNT, and 4-NH2-DNT in the urine [59], and to the formation of covalent adducts with microsomal liver and kidney proteins, hemoglobin, and other blood proteins [60], The acid hydrolysis of adducts yielded mainly 2-NH2-DNT (2-ADNT) and 4-NH2-DNT (4-ADNT). Incubation of rat liver microsomes with TNT and NADPH under aerobic conditions resulted in the formation of NH2-DNTs and the transient metabolite 4-NHOH-DNT [57], The formation of covalent protein adducts with TNT metabolites was enhanced by the presence of 02 and decreased by GSH. This is consistent with the scheme of the TNT adduct formation with the central role of the nitroso metabolite (NO-DNT) reaction with protein or nonprotein thiols (RSH Equation 9.11) [57], The acid hydrolysis of the sulfinamide adduct (RS(0)-NH-DNT) formed after the rearrangement of the semimercaptal (RS-N(OH)-DNT Equation 9.12) will yield NH2-DNT. The mixture of NHOH-DNTs inhibits bacterial glyceraldehyde-3-phosphate dehydrogenase and glucose-6-phosphate dehydrogenase more efficiently than TNT [61]. This was attributed to the covalent modification of protein -SH groups. 

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