Extracellular Alpha-Galactosidase (Ec 3.2.1.22) From Aspergillus-Ficuum Nrrl-3135 Purification And Characterization

    Authors

    I. G. Zapater; A. H. J. Ullah;R. J. Wodzinski

    Comments

    Authors: contact us about adding a copy of your work at STARS@ucf.edu

    Abbreviated Journal Title

    Prep. Biochem.

    Keywords

    POLYACRYLAMIDE-GEL ELECTROPHORESIS; OPTIMUM ACID-PHOSPHATASE; SOYBEAN; MILK; ROOT-TIPS; GLYCOSIDASES; ISOENZYMES; SEQUENCE; PHYTASE; NIGER; Biochemistry & Molecular Biology

    Abstract

    Extracellular alpha-galactosidase, a glycoprotein from the extracellular culture fluid of Aspergillus ficuum grown on glucose and raffinose in a batch culture system, was purified to homogeneity in five steps by ion exchange and hydrophobic interaction chromatography. The molecular mass of the enzyme was 70.8 Kd by SDS polyacrylamide gel electrophoresis and 74.1 Kd by gel permeation HPLC. On the basis of a molecular mass of 70.7 Kd, the molar extinction coefficient of the enzyme at 279 nm was estimated to be 6.1 X10(4) M-1 cm-1. The purified enzyme was remarkably stable at 0-degrees-C. It had a broad temperature optimum and maximum catalytic activity was at 60-degrees-C. It retained 33% of its activity after 10 min. at 65-degrees-C. It had a pH optimum of 6.0. It retained 62% of its activity after 12 hours at pH 2.3. The K(ms) for p-nitrophenyl-alpha-D-galactopyranoside, o-nitrophenyl-alpha-D-galactopyranoside and m-nitrophenyl-alpha-D-galactopyranoside are: 1462, 839 and 718-mu-M. The enzyme was competitively inhibited by mercury (19.8-mu-M), silver (21.5-mu-M), copper (0.48 mM), zinc (0.11 mM), galactose (64.0 mM) and fructose (60.3 mM). It was inhibited non-competitively by glucose (83.2 mM) and uncompetitively by mannose (6.7 mM).

    Journal Title

    Preparative Biochemistry

    Volume

    20

    Issue/Number

    3-4

    Publication Date

    1-1-1990

    Document Type

    Article

    Language

    English

    First Page

    263

    Last Page

    296

    WOS Identifier

    WOS:A1990FG18500006

    ISSN

    0032-7484

    Share

    COinS