:Methionyl aminopeptidase

{{Short description|Class of enzymes}}

{{Infobox enzyme

| Name = Methionyl aminopeptidase

| EC_number = 3.4.11.18

| CAS_number = 61229-81-0

| GO_code =

| image =

| width =

| caption =

}}

Methionyl aminopeptidase ({{EC number|3.4.11.18}}, methionine aminopeptidase, peptidase M, L-methionine aminopeptidase, MAP) is an enzyme.{{cite journal | vauthors = Yoshida A, Lin M | title = NH₂-terminal formylmethionine- and NH₂-terminal methionine-cleaving enzymes in rabbits | journal = J. Biol. Chem. | volume = 247 | pages = 952–957 | year = 1972 | issue = 3 | doi = 10.1016/S0021-9258(19)45699-8 | pmid = 4110013 | doi-access = free }}{{cite journal | vauthors = Tsunasawa S, Stewart JW, Sherman F | title = Acylamino acid-releasing enzyme from rat liver | journal = J. Biol. Chem. | volume = 260 | pages = 5382–91| year = 1985 | issue = 9 | doi = 10.1016/S0021-9258(18)89033-0 | pmid = 2985590 | doi-access = free }}{{cite journal | vauthors = Freitas JO, Termignoni C, Guimarães JA | title = Methionine aminopeptidase associated with liver mitochondria and microsomes | journal = Int. J. Biochem. | volume = 17 | pages = 1285–1291 | year = 1985 | issue = 12 | doi = 10.1016/0020-711x(85)90049-7 | pmid = 3937747 }}{{cite journal | vauthors = Ben-Bassat A, Bauer K, Chang SY, Myambo K, Boosman A, Chang S | title = Processing of the initiation methionine from proteins: properties of Escherichia coli methionine aminopeptidase and its gene structure | journal = J. Bacteriol. | volume = 169 | pages = 751–757 | year = 1987 | issue = 2 | doi = 10.1128/jb.169.2.751-757.1987 | pmid = 3027045 | pmc=211843}}{{cite journal | vauthors = Roderick SL, Matthews BW | title = Crystallization of methionine aminopeptidase from Escherichia coli | journal = J. Biol. Chem. | volume = 263 | pages = 16531 | year = 1988 | issue = 32 | doi = 10.1016/S0021-9258(18)37422-2 | pmid = 3141408 | doi-access = free }} This enzyme catalyses the following chemical reaction

: Release of N-terminal amino acids, preferentially methionine, from peptides and arylamides

This membrane-bound enzymatic activity is present in both prokaryotes and eukaryotes. Human proteins possessing this activity include METAP1, METAP2, METAP1D (mitochondrial), and RNPEPL1.