The identification of the N tau-methyl histidine-containing dipeptide, balenine, in muscle extracts from various mammals and the chicken.

The occurrence of the dipeptide, balenine (beta-alanyl-N tau-methyl histidine), has been identified by comparative chromatography in extracts of muscles from 9 species of mammal, including man, and the chicken. The identity of the dipeptide from 6 mammalian species and chicken was confirmed by preparative isolation prior to determination of the amino acid composition and N-terminal residue. In all cases, the dipeptide contained equimolar amounts of beta-alanine and N tau-methyl histidine with beta-alanine as the N-terminus. The concentration of the dipeptide varied dramatically between species, being just detectable in the muscle of man and rat while present at concentrations of up to 14 mumol/g wet muscle in adult pigs. It is proposed that balenine, like carnosine and anserine, should be regarded as a normal constituent of muscle.