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Aryl sulfatase from Naja nigricolis venom: Characterization and possible contribution in the pathology of snake poisoning
Author(s) -
Nok Andrew J.,
Abubakar M. S.,
Adaudi Ambrose,
Balogun E.
Publication year - 2003
Publication title -
journal of biochemical and molecular toxicology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.526
H-Index - 58
eISSN - 1099-0461
pISSN - 1095-6670
DOI - 10.1002/jbt.10061
Subject(s) - chemistry , sephadex , venom , hydrolysis , sulfatase , chromatography , enzyme , arrhenius plot , snake venom , stereochemistry , biochemistry , activation energy , organic chemistry
The venom of Naja nigricolis was found to contain a high level of the enzyme aryl sulfatase. The enzyme was isolated from the venom of N. nigriclois and purified to electrophoretic homogeneity by gel chromatography on Sephadex G‐100, DEAE‐cellulose, and phenyl‐sepharose columns. The enzyme was optimally active at pH 5 and 40°C. Arrhenius plot for the determination of the activation energy ( E a ) gave the value 25 kJ/mol with a half‐life ( t 1/2 ) of 5 min at 50°C. It was highly activated by Fe 2+ and Ca 2+ and inhibited by Co 2+ and Mn 2+ . The enzyme catalyzed the hydrolysis of the fluorescent compound methylumbelliferyl‐sulfate (MU‐SO 4 ). Double reciprocal plots of initial velocity data, using MU‐SO 4 as substrate, gave a K M value of 110 μM and V max of 225 μmol min −1 mg −1 . N. nigricolis Aryl sulphatase also hydrolyzed chondroitin‐4‐sulphate. It was inhibited competitively by N ‐acetyl glucosamine sulfate (GlcNAc‐SO 4 ), glucose‐6‐sulfate (Glc‐6‐SO 4 ), and glucose 1‐sulfate (Glc‐1‐SO 4 ). Extrapolated inhibition binding constants ( K i ) gave the values of 3, 25, and 315 μM for GlcNAc‐SO 4 , Glc‐6‐SO 4 , and Glc‐1‐SO 4 respectively. © 2003 Wiley Periodicals, Inc. J Biochem Mol Toxicol 17:59–66, 2003; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.10061