An enzyme transferring amino groups from l-alanine to 2-ketoglutarate, or the reverse (from l-glutamate to pyruvate); one d-alanine transaminase effects the same reaction, but using d-alanine and d-glutamate. Serum concentration is increased in viral hepatitis and myocardial infarction. SYN: alanine transaminase, glutamic-pyruvic transaminase, serum glutamic:pyruvic transaminase.