Purification and partial characterization of peptidase-1, a sex-linked enzyme inPleurodeles waltl(urodele amphibian)

Abstract

Peptidase-1 is a sex-linked enzyme, which can be purified from the liver of the amphibian urodele Pleurodeles waltl. We estimated its apparent molecular mass as 170 kDa by gel filtration chromatography. The enzyme is composed of two subunits with apparent molecular masses of 90 and 99 kDa. It is strongly inhibited by ethylenediaminotetraacetic acid, ethylene glycol bis( beta -aminoethyl ether)-N,N-tetraacetic acid, and 1,10-phenanthroline, indicating that peptidase-1 is a metallopeptidase. Peptidase-1 has optimal activity at 55°C and pH 8.5. This acidic enzyme displays two apparent isoelectric points, at 4.9 and 5.2, and is essentially located in the cytosolic subcellular fraction.Key words: peptidase-1, amphibian, purification, characterization, sex-linked enzyme.