Isolation and characterization of rat kidney alanine aminopeptidase

Rat alanine aminopeptidase was purified from kidney by isolation of the brush border membrane with CaCl2 followed by differential centrifugation and tryptic proteolysis. It is a glycoprotein with a molecular weight of approximately 210,000 daltons comprising two 110,000-dalton subunits and has an amino acid composition similar to that of the human enzyme. Two zinc atoms are covalently bound to each protein subunit.