Methionine-preferring broad specificity aminopeptidase from chicken egg-white

From chicken egg-white a broad specificity aminopeptidase is isolated. The presence of high molecular mass, hydrophobic aminopeptidase is also revealed. Isolated enzyme hydrolysed aliphatic, aromatic and basic aminoacyl-2-naphthylamides, and di- to hexapeptides, with a preference for methionine at the NH2-end, and basic or bulky hydrophobic residue at the penultimate position. The enzyme is a hydrophilic, acidic glycoprotein of M(r) approximately 180,000, optimally active at pH 7.0-7.5 and at a temperature of 50 degrees C. Amastatin, bestatin and o-phenanthroline are strong, and puromycin, EDTA and iodoacetamide less potent, inhibitors. Co2+ activates the enzyme. The isolated enzyme can be classified as a methionine-preferring broad specificity aminopeptidase.