Alanine aminopeptidase of guinea-pig brain: A broad specificity cytoplasmic enzyme capable of hydrolysing short and intermediate length peptides

Purification and characterization of aminopeptidase N from chicken intestine with potential application in debittering

“…The enzyme has been characterized from a wide variety of sources [6][7][8][9][10][11][12][13][14][15][16][17]. Although many authors have shown that this enzyme is membrane associated [8], a few studies on cytosolic form of this enzyme have also been reported [15,12].…”

Substrate Specificity of Aminopeptidase from the Mid-gut Gland of the Scallop (Patinopecten yessoensis)

“…The k cat =K m values for various pNA and MCA substrates were of the same levels as those for MCA substrates in alanine aminopeptidase from guinea-pig brain, 9) for peptide substrates in ratliver cytosol, 8) and for pNA substrates and dipeptides in Aeromonas caviae aminopeptidase. 16) The results of the action for various peptides and the kinetic study for pNA and MCA substrates showed that scallop aminopeptidase is specific for alanine in the amino-termini of substrates and resembles mammal cytosol alanyl aminopeptidases [4][5][6]8,9) with respect to substrate specificity. Our previous paper 15) demonstrated, however, that the enzyme differs from mammal cytosol alanyl aminopeptidase in molecular weight and sensitivity to puromycin, SH-blocking reagents, and divalent metal ions.…”

“…1) There are substantial reports concerning substrate specificity, biological function, and structure of aminopeptidases in prokaryotes and mammals. 2,3) Among various aminopeptidases, the alanyl aminopeptidases (EC 3.4.11.2, 3.4.11.14), which preferentially liberate amino-terminal amino acids, such as Ala, Met, Leu, and Tyr of peptides, are widely distributed in mammalian tissues and body fluids, [4][5][6][7][8][9] and in plant tissues 10) and cyanobacteria, 11) as a membrane or cytosolic type. These enzymes from mammals are believed to participate in the metabolism of hormones and neurotransmitters.…”

Peptide Metabolism in Cytoplasm of Brain Cells

“…T h e addition of an extra amino acid at the C-terminus of a peptide that is not hydrolysed by this enzyme results in a tripeptide that is hydrolysed. Thus, whereas Asp-Tyr-Met and Tyr-Gly are not hydrolysed by alanine aminopeptidase, the tripeptides Asp-TyrMet and Tyr-Gly-Gly are hydrolysed [86]. Optimum activity is observed at pH 7.0 and is enhanced by the presence of 1 mM DTT.…”

“…Metalchelating agents, thiol-reactive agents, bestatin, puromycin and particularly amastatin (K, = 0.1 pM) are severely inhibitory. T h e purified alanine aminopeptidase from guinea-pig brain was found to be a single polypeptide with a molecular mass of 104000 Da [86].…”