Accepted name: carnosine N-methyltransferase
Reaction: S-adenosyl-L-methionine + carnosine = S-adenosyl-L-homocysteine + anserine
Systematic name: S-adenosyl-L-methionine:carnosine N-methyltransferase
1.  McManus, I.R. Enzymatic synthesis of anserine in skeletal muscle by N-methylation of carnosine. J. Biol. Chem. 237 (1962) 1207–1211.
[EC created 1972]
Deleted entry: Xaa-His dipeptidase. The activity is covered by EC, cytosol nonspecific dipeptidase and EC, β-Ala-His dipeptidase.
[EC created 1961 as EC, transferred 1972 to EC, modified 1989 (EC created 1981, incorporated 1992), deleted 2011]
Accepted name: Xaa-methyl-His dipeptidase
Reaction: Hydrolysis of anserine (β-alanyl┼Nπ-methyl-L-histidine), carnosine, homocarnosine, glycyl┼leucine and other dipeptides with broad specificity
Other name(s): anserinase; aminoacyl-methylhistidine dipeptidase; acetylhistidine deacetylase; N-acetylhistidine deacetylase; α-N-acetyl-L-histidine aminohydrolase; X-methyl-His dipeptidase
1.  Jones, N.R. The free amino acids of fish. 1-Methylhistidine and β-alanine liberation by skeletal muscle anserinase of codling (Gadus callarias). Biochem. J. 60 (1955) 81–87. [PMID: 14363188]
2.  Baslow, M.H. and Lenney, J.F. α-N-Acetyl-L-histidine amidohydrolase activity from the brain of the skipjack tuna Katsuwonus pelamis. Can. J. Biochem. 45 (1967) 337–340. [PMID: 6067033]
3.  Lenney, J.F., Baslow, M.H. and Sugiyama, G.H. Similarity of tuna N-acetylhistidine deacetylase and cod fish anserinase. Comp. Biochem. Physiol. B Comp. Biochem. 61 (1978) 253–258. [PMID: 318374]
[EC created 1961 as EC, transferred 1972 to EC, modified 1981 (EC created 1972, incorporated 1981)]
Accepted name: β-Ala-His dipeptidase
Reaction: Preferential hydrolysis of the β-Ala┼His dipeptide (carnosine), and also anserine, Xaa┼His dipeptides and other dipeptides including homocarnosine
Other name(s): serum carnosinase
Comments: Present in the serum of humans and higher primates, but not in the serum of other mammals. Activated by Cd2+ and citrate. Belongs in peptidase family M20.
1.  Lenney, J.F., George, R.P., Weiss, A.M., Kucera, C.M., Chan, P.W.H. and Rinzler, G.S. Human serum carnosinase: characterization, distinction from cellular carnosinase, and activation by cadmium. Clin. Chim. Acta 123 (1982) 221–231. [PMID: 7116644]
2.  Jackson, M.C., Kucera, C.M. and Lenney, J.F. Purification and properties of human serum carnosinase. Clin. Chim. Acta 196 (1991) 193–206. [PMID: 1903095]
[EC created 1992]
Accepted name: carnosine synthase
Reaction: ATP + L-histidine + β-alanine = ADP + phosphate + carnosine
Glossary: carnosine = N-β-alanyl-L-histidine
Other name(s): carnosine synthetase; carnosine-anserine synthetase; homocarnosine-carnosine synthetase; carnosine-homocarnosine synthetase; L-histidine:β-alanine ligase (AMP-forming) (incorrect)
Systematic name: L-histidine:β-alanine ligase (ADP-forming)
Comments: This enzyme was thought to form AMP [1,2], but studies with highly purified enzyme proved that it forms ADP [4]. Carnosine is a dipeptide that is present at high concentrations in skeletal muscle and the olfactory bulb of vertebrates [3]. It is also found in the skeletal muscle of some invertebrates. The enzyme can also catalyse the formation of homocarnosine from 4-aminobutanoate and L-histidine, with much lower activity [4].
1.  Kalyankar, G.D. and Meister, A. Enzymatic synthesis of carnosine and related β-alanyl and γ-aminobutyryl peptides. J. Biol. Chem. 234 (1959) 3210–3218. [PMID: 14404206]
2.  Stenesh, J.J. and Winnick, T. Carnosine-anserine synthetase of muscle. 4. Partial purification of the enzyme and further studies of β-alanyl peptide synthesis. Biochem. J. 77 (1960) 575–581. [PMID: 16748858]
3.  Crush, K.G. Carnosine and related substances in animal tissues. Comp. Biochem. Physiol. 34 (1970) 3–30. [PMID: 4988625]
4.  Drozak, J., Veiga-da-Cunha, M., Vertommen, D., Stroobant, V. and Van Schaftingen, E. Molecular identification of carnosine synthase as ATP-grasp domain-containing protein 1 (ATPGD1). J. Biol. Chem. 285 (2010) 9346–9356. [PMID: 20097752]
[EC created 1965, modified 2010]