Purification and properties of an aminopeptidase from the mid-gut gland of scallop (Patinopecten yessoensis) |
| |
Authors: | Umetsu Hironori Arai Mito Ota Toshinori Kudo Ryohei Sugiura Hitomi Ishiyama Hiroyuki Sasaki Kazuo |
| |
Institution: | a Graduate School of Environmental Science, Aomori University, Kobata, Aomori 030-0943, Japan;b Institute of Bioscience and Biotechnology, Aomori University, Kobata, Aomori 030-0943, Japan |
| |
Abstract: | An aminopeptidase was isolated from the mid-gut gland of Patinopecten yessoensis. The enzyme was purified from an acetone-dried preparation by extracting, ammonium sulfate precipitation, Hi-Load Q column chromatography, isoelectric focusing, and POROS HP2 and HQ column chromatography. The molecular weight of the enzyme was estimated to be 61 kDa by SDS-polyacrylamide gel electrophoresis and 59 kDa by gel permeation chromatography. The isoelectric point of the enzyme was 5.2 and the optimum pH was 7.0 toward leucine p-nitroanilide (Leu-pNA). The enzyme was inhibited by o-phenanthroline. The activity of the enzyme treated with o-phenanthroline was completely recovered by adding excess Zn2+. Relative hydrolysis rates of amino acid-pNAs and amino acid-4-methylcoumaryl-7-amides (amino acid-MCAs) indicated that the enzyme preferred substrates having Ala or Met as an amino acid residue. The enzyme had a Km of 32.2 μM and kcat of 29.5 s−1 with Ala-pNA and a Km of 11.1 μM and kcat of 9.49 s−1 with Ala-MCA. The enzyme sequentially liberated amino acids from the amino-termini of Ala–Phe–Tyr–Glu. |
| |
Keywords: | Patinopecten yessoensis Scallop Mid-gut gland Cytosol Aminopeptidase Purification Characterization Substrate specificity Kinetic parameter |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|