AbstractsBiology & Animal Science

A study of animal and plant transaminases.

by Ralph. Witty




Institution: McGill University
Department: Department of Biochemistry.
Degree: PhD
Year: 1951
Keywords: Biochemistry.
Record ID: 1582115
Full text PDF: http://digitool.library.mcgill.ca/thesisfile124071.pdf


Abstract

In 1927 Dorothy Needham (l), observed that when glutamic acid was added to minced pigeon breast muscle it disappeared without a parallel formation of ammonia, or a decrease in the total amino group concentration. She assumed,that the amino group of glutamic acid was transferred to some reactive carbohydrate residue to form a new amino acid. A similar phenomenon was observed by Banga and Szent- Gyorgyi (8), who noted that the rate of oxalacetic acid disappearance from pigeon breast muscle preparations was increased by glutamic acid. However, they did not recognize this as a transamination reaction. The correctness of Needham’s assumption was demonstrated by Braunstein and Kritzmann (2), when they described the reversible reaction in muscle between glutamic acid and pyruvic acid which proceeds as follows: 1 (+) glutamic + pyruvic →/← αketoglutaric + 1 (+) alanine. The enzyme catalysing the reaction they termed aminopherase. They proved its reversibility by isolating and chemically identifying the alanine and glutamic acid formed. The equilibrium was reached in 20 to 25 minutes under their conditions. In a later study (3) they found the enzyme was not limited to skeletal muscle but was present, also, in heart muscle, brain, liver and kidney [...]