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Subunit structured of pig small-intestinal brush-border aminopeptidase N.

ABSTRACT: Aminopeptidase N (EC 3.4.11.2), when isolated from pig intestine in either the proteinase- or detergent-released form, frequently appears to contain three polypeptide chains, here termed alpha, beta and gamma. We have established by an immunological technique that the beta- and gamma-polypeptides are derived from the alpha-chain and that the intact enzyme is a dimer, alpha 2. Each alpha-chain of the detergent form was shown to contain a hydrophobic anchor peptide about 35 amino acid residues in length, which included the N-terminal sequences. A peptide bond in the alpha-chain was very sensitive to proteolysis. Its cleavage generated the commonly observed forms: alpha beta gamma and beta 2 gamma 2. The gamma-fragment, which lacked the anchor peptide, was derived from the C-terminal part of the alpha-chain.

SUBMITTER: Benajiba A

PROVIDER: S-EPMC1163168 | biostudies-other | 1981 Sep

REPOSITORIES: biostudies-other

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