Biological Chemistry - Berezov, T. T., Korovkin, B. F. 1998

Metabolism of Complex Proteins
Nucleic Acid Metabolism
Catabolism of Pyrimidine Nucleosides

The sequence of enzymatic reactions in the Hydrolysis of pyrimidine nucleosides can be represented as follows:

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The Initial Stages of pyrimidine nucleotide degradation are catalyzed by specific Enzymes. The final products of the reaction are СО2, NH3, urea, ß-Alanine, and ß-aminoisobutyric acid. It should be noted that the hydrolytic pathway of pyrimidine degradation is apparently the main route for The formation of ß-alanine, which can serve as a precursor for the synthesis of anserine and carnosine (see Chapter 20), as well as for CoA Biosynthesis. It is known that ß-alanine undergoes further degradation in animal Tissues. A specific aminotransferase has been discovered in animal tissues that catalyzes Transamination between ß-alanine and pyruvic acid. This reversible reaction yields a-alanine and formylacetate (malonic semialdehyde):

The resulting formylacetate then undergoes oxidative decarboxylation to form carbon dioxide and acetyl-CoA.



Last update: 06/08/2026

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