The Journal of biological chemistry
-
The amino acid sequence of bovine eye lens leucine aminopeptidase has been determined. Cyanogen bromide fragments, the COOH-terminal hydroxylamine fragment, and a large fragment obtained by digestion with Staphylococcus aureus protease were isolated from reduced and S-alkylated leucine aminopeptidase. The amino acid sequences of these fragments were determined by automated sequence analysis, by manual direct Edman degradation, and by the dansyl-Edman technique. ⋯ The polypeptide chain of leucine aminopeptidase comprises 478 residues, corresponding to a molecular weight of 51,691. No significant sequence homology with any other published protein primary structure could be detected. This is the first report of a complete amino acid sequence of an enzyme belonging to the class of two metal peptidases.
-
Cyanogen bromide (CB) cleavage of Neurospora tyrosinase resulted in four major fragments, CB1 (222 residues), CB2 (82 residues), CB3 (68 residues), and CB4 (35 residues), and one minor overlap peptide CB2-4 (117 residues) due to incomplete cleavage of a methionylthreonyl bond. The sum of the amino acid residues of the four major fragments matches the total number of amino acid residues of the native protein. ⋯ The peptides were the products of cleavage by mild acid hydrolysis, trypsin, pepsin, chymotrypsin, thermolysin, and Staphylococcus aureus protease V8. The cyanogen bromide fragment CB1 was found to contain two unusual amino acids whose chemical structure will be presented in the following paper.