Characterization of a β-D-mannosidase from a marine gastropod, Aplysia kurodai

スポンサーリンク

概要

• 論文の詳細を見る

• A β-D-mannosidase (EC 3.2.1.25) with a molecular mass of approximately 100 kDa was purified from the digestive fluid of a marine gastropod Aplysia kurodai by ammonium sulfate fractionation followed by column chromatographies on TOYOPEARL Butyl-650 M, TOYOPEARL DEAE-650 M, and Superdex 200 10/300 GL. This enzyme, named AkMnsd in the present study, showed optimal activities at pH 4.5 and 40℃ and was stable at the acidic pH range from 2.0 to 6.7 and the temperature below 38℃. The Km and Vmax values for AkMnsd determined at pH 6.0 and 30℃ with p-nitrophenyl β-D-mannopyranoside were 0.10 mM and 3.75 μmol/min/mg, respectively. AkMnsd degraded various polymer mannans as well as mannooligosaccharides liberating mannose as a major degradation product. Linear mannan from green alga Codium fragile was completely depolymerized by AkMnsd in the presence of AkMan, an endolytic β-mannanase, which we previously isolated from the same animal (Zahura et al., Comp. Biochem. Physiol. B 157, 137-148 (2010)). A cDNA encoding AkMnsd was amplified from the Aplysia hepatopancreas cDNA by the PCR using degenerated primers designed on the basis of N-terminal and internal amino-acid sequences of AkMnsd. The cloned AkMnsd cDNA consisted of 2985 bp and encoded an amino-acid sequence of 931 residues with the calculated molecular mass of 101970 Da. The deduced sequence of AkMnsd showed 20-43% amino-acid identity to those of glycoside-hydrolase-family 2 (GHF2) β-mannosidases. The catalytically important amino-acid residues determined in GHF2 enzymes were completely conserved in AkMnsd. Thus, AkMnsd is regarded as a new member of GHF2 mannosidase from marine gastropod.

著者

• Ojima Takao

  Lab. Of Marine Biotechnology And Microbiology Graduate School Of Fisheries Sciences Hokkaido Univ. H

• Rahman Mohammad

  Laboratory Of Marine Biotechnology And Microbiology Graduate School Of Fisheries Sciences Hokkaido University

• Inoue Akira

  Laboratory Of Marine Biotechnology And Microbiology Graduate School Of Fisheries Sciences Hokkaido University

関連論文

• An endo-β-1,4-mannanase, AkMan, from the common sea hare Aplysia kurodai
• Isolation and characterization of two alginate lyase isozymes, AkAly28 and AkAly33, from the common sea hare Aplysia kurodai
• Comparative study on general properties of alginate lyases from some marine gastropod mollusks
• N-Terminal Modification and Its Effect on the Biochemical Characteristics of Akazara Scallop Tropomyosins Expressed in Escherichia coli
• Preparation of β-1,3-glucanase from scallop mid-gut gland drips and its use for production of novel heterooligosaccharides
• cDNA cloning and bacterial expression of an endo-β-1,4-mannanase, AkMan, from Aplysia kurodai
• cDNA cloning of an alginate lyase from a marine gastropod Aplysia kurodai and assessment of catalytically important residues of this enzyme.
• Characterization of a β-D-mannosidase from a marine gastropod, Aplysia kurodai
• cDNA cloning and bacterial expression of a PL-14 alginate lyase from a herbivorous marine snail Littorina brevicula
• Heat-stability and primary structure of the major alginate lyase isozyme LbAly35 from Littorina brevicula

スポンサーリンク