A monovalent anion affected multi-functional cellulase EGX from the mollusca, Ampullaria crossean

A cellulose hydrolytic enzyme was isolated from the stomach juice of Ampullaria crossean, a kind of herbivorous mollusca. The enzyme was purified 45.3-fold to homogenety by ammonium sulfate precipitation, DEAE-Sephadex A-50 column, Bio-gel P-100 gel filtration column, and phenyl-Sepharose CL-4B colu...

Full description

Saved in:
Bibliographic Details
Published in:Protein expression and purification 2003-09, Vol.31 (1), p.108-114
Main Authors: Wang, Ji, Ding, Ming, Li, Yan-Hong, Chen, Qin-Xi, Xu, Gen-Jun, Zhao, Fu-Kun
Format: Article
Language:English
Subjects:
Ammonium Sulfate - chemistry
Ampullaria crossean
Animals
Anions - chemistry
Blotting, Western
Bromides - chemistry
Carboxymethylcellulose Sodium - metabolism
Cellulase
Cellulase - chemistry
Cellulase - metabolism
Cellulases - chemistry
Cellulases - isolation & purification
Cellulases - metabolism
Chloride regulation
Chlorides - chemistry
DEAE-Dextran - analogs & derivatives
DEAE-Dextran - chemistry
EGX
Electrophoresis, Polyacrylamide Gel
Endo-1,4-beta Xylanases - chemistry
Endo-1,4-beta Xylanases - metabolism
Endo-β-1,4-glucanase
Endo-β-1,4-xylanase
Enzyme Activation
Enzyme Stability
Exo-β-1,4-glucanase
Fluorides - chemistry
Gastric Juice - enzymology
Glucan 1,4-beta-Glucosidase - chemistry
Glucan 1,4-beta-Glucosidase - metabolism
Glucosides - metabolism
Glycosylation
Hydrogen-Ion Concentration
Isoelectric Point
Kinetics
Liver - chemistry
Liver - metabolism
Molecular Weight
Mollusca - enzymology
Monovalent anion
Nitrates - chemistry
Spectrometry, Fluorescence
Starch - metabolism
Substrate Specificity
Temperature
Xylans - metabolism
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:A cellulose hydrolytic enzyme was isolated from the stomach juice of Ampullaria crossean, a kind of herbivorous mollusca. The enzyme was purified 45.3-fold to homogenety by ammonium sulfate precipitation, DEAE-Sephadex A-50 column, Bio-gel P-100 gel filtration column, and phenyl-Sepharose CL-4B column chromatography. The enzyme was designated as cellulase EGX. The purified enzyme is a multi-functional enzyme with the activities of exo-β-1,4-glucanase (14.84 U/mg for p-nitrophenyl β- d-cellobioside), endo-β-1,4-glucanase (40.3 U/mg for carboxymethyl cellulose), and endo-β-1,4-xylanase (196 U/mg for soluble xylan from birchwood). The monovalent anions such as F −, Cl −, Br −, I −, and NO 3 − are essential for its exo-β-1,4-glucanase activity but have no effect on the activity for xylan, while I − higher than 5 mM would inhibit the exo-β-1,4-glucanase activity. The monovalent anions Cl − and Br − activate its endo-β-1,4-glucanase activity. Binding of Cl − enhances the thermostability of EGX, but does not affect its fluorescence emission spectrum. The molecular mass of EGX is 41.5 kDa, as determined by SDS–PAGE. The pI value is about pH 7.35. The xylan hydrolytic activity of EGX reaches to the maximum between pH 4.8 and 6.0 and the pNPC hydrolytic activity reaches the maximum between pH 4.8 and 5.6, while that for CMC hydrolytic activity is between pH 4.4 and 4.8. Preliminary results showed that the enzyme was secreted by the mollusca itself.
ISSN:1046-5928
1096-0279
DOI:10.1016/S1046-5928(03)00131-1