Alanine anaerobic conditions

Experimental support for the mechanism of Eq. 15-26 has been obtained using D-chloroalanine as a substrate for D-amino acid oxidase.252-254 Chloro-pyruvate is the expected product, but under anaerobic conditions pyruvate was formed. Kinetic data obtained with a-2H and a-3H substrates suggested a common intermediate for formation of both pyruvate and chloro-pyruvate. This intermediate could be an anion formed by loss of H+ either from alanine or from a C-4a adduct. The anion could eliminate chloride ion as indicated by the dashed arrows in the following structure. This would lead to formation of pyruvate without reduction of the flavin. Alternatively, the electrons from the carbanion could flow into the flavin (green arrows), reducing it as in Eq. 15-26. A similar mechanism has been suggested for other flavoenzymes 249/255 Objections to the carbanion mechanism are the expected... 

In 1937, Alexander E. Braunstein (1902-86), working in Moscow, was studying the metabolism of glutamate in muscles and made the interesting observation that when glutamate levels decrease so do lactate (anaerobic conditions) or pyruvate (aerobic conditions). In each case the concentrations of alanine increase. He had discovered the reversible transamination reactions that connect the intermediary metabolisms of proteins and carbohydrates. 

Other amino acids reported to accumulate under anaerobic conditions are alanine (Effer and Ranson, 1967 Guinn and Brinkeroff, 1970 Streeter and Thompson, 1972), glycine, serine (Guinn and Brinkeroff, 1970), and proline (Wample and Bewley, 1975). The accumulation of proline in flooded (immersed) sunflower plants was, however, associated with a loss in leaf turgid-... 

Resting cells of P. freudenreichii under both aerobic and anaerobic conditions rapidly degraded aspartic acid, glycine and alanine, and more slowly other amino acids. But large strain and species variations were observed, and certain specificities in the metabolism of different amino acids were found (Langsrud et al, 1995). 

Muscle activity involves processes such as aerobic and anaerobic glycolysis and is therefore accompanied by an increased pyruvate production. Consequently, the pyruvate transamination product alanine will be increased after exercise. Heavy exercise may be associated with an increased need of creatine biosynthesis from arginine. Ornithine is a by-product of this pathway and may be increased under these conditions. 

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