Enzyme kinetic properties of α-1,4-glucosidase in Bacillus thuringiensis

Rowe, Gerald E.; Margaritis, Argyrios

doi:10.1016/s1369-703x(03)00147-5

Cited by 10 publications

(5 citation statements)

References 25 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2). The obtained specific activity in the present investigation is higher than that reported for the enzyme from Bacillus thuringiensis (Rowe and Margaritis, 2004) and comparable to that purified from Geobacillus thermodenitrificans (Ezeji and Bahl, 2006). …”

Section: Purification Of -Glucosidasesupporting

confidence: 61%

Essential groups and stability of α-glucosidase ofPenicillium notatum

2009

View full text Add to dashboard Cite

--Glucosidase ( -D-glucoside glucohydrolase, EC 3.2.1.20) was isolated from Penicillium notatum. The enzyme was induced by gibberellic acid (GA 3 ). The GA 3 -mediated increase in the enzyme activity was repressed in presence of abscisic acid, cycloheximide and the antibiotics chloramphenicol, cordycepin, and rifampicin which are inhibitors of protein synthesis. -Glucosidase was purified 440-fold with of 27.8-fold of purification. The enzyme was immobilized using chitosan gel. The optimal pH values were 6.5 and 7.5 for free and the immobilized enzymes, respectively. The optimal temperatures were 50 and 65 °C for free and immobilized enzymes, respectively. The enzyme hydrolyzed maltose, sucrose, isomaltose, maltotriose but not starch, amylopectin and amylose. Trehalose and glycerol protected the free and immobilized enzymes against inactivation at 70 °C, however trehalose was the better protector. Phytate protected the free enzyme against heat inactivation at both 65 and 70 °C. 2,4,6 Trinitrobenzenesulfonic acid, butanedione and diethylpyrocarbonate inactivated the enzyme and suggest that, lysyl, arginyl and histidyl groups are taking part in enzyme catalysis. The inactivation by the three compounds was protected by the substrate para-nitrophenyl--D-glucopyranoside. Treatment of the enzyme with 1-ethyl-3(3-dimethyl aminopropyl)-carbodiimide, p-chloromercuribenzoate, N-bromosuccinimide, N-acetlyimidazole revealing the involving of carboxyl, sulfhydryl, trptophenyl and tyrosyl groups, respectively in the catalysis of -glucosidase. EDTA, o-phenanthroline, dipyridyl and 8-quinolinol inhibited the enzyme activity and the inhibition was higher in case of free enzyme compared with immobilized enzyme.

show abstract

Section: Purification Of -Glucosidasesupporting

confidence: 61%

Essential groups and stability of α-glucosidase ofPenicillium notatum

2009

View full text Add to dashboard Cite

show abstract

“…The initial speed of the reaction ( V in µmol/mg/min) was calculated for each initial concentration of substrate ( S in g/L). Then, Lineweaver– Burk plots (Rowe and Margaritis 2004) were represented using Hyper32 software (University of Liverpool, Liverpool, U.K.). The Michaelis–Menten kinetic parameters ( K m and V max ) were estimated using hyperbolic regression analysis with 95% confidence intervals.…”

Section: Methodsmentioning

confidence: 99%

CLONING AND SEQUENCING OF THE α-AMYLASE GENE FROMBACILLUS SUBTILISUS116 STRAIN ENCODING AN ENZYME CLOSELY IDENTICAL TO THAT FROMBACILLUS AMYLOLIQUEFACIENSBUT DISTINCT IN THERMAL STABILITY

Messaoud

Mabrouk

Jemli

et al. 2010

Journal of Food Biochemistry

View full text Add to dashboard Cite

The gene encoding for the α‐amylase AMYUS116 was cloned and sequenced. The amino acid sequence of AMYUS116 exhibited an almost perfect homology with the α‐amylase BACAAM, excluding the residues N205 and N217 of AMYUS116 that were changed to H205 and I217 into BACAAM. Three mutant derivatives from AMYUS116 (N205H, N217I and N205H/N217I) were created by site‐directed mutagenesis and their physicochemical and kinetic properties were compared with those of the wild‐type enzymes. Therefore, the undertaken amylases mainly generated maltohexaose from starch and had radically the same kinetic parameters and optimum pH and temperature. They, however, were significantly distinct in thermal stability; AMYUS116 was more thermosensible as its half‐life time at 80C was 13 min, while those of BACAAM and the double mutant were likewise 38 min. The single‐mutant amylases exhibited an identically intermediate thermal stability as their half‐life times at 80C were roughly 22 min. PRACTICAL APPLICATIONS Of particular interest to the current search is that the different thermal stability between AMYUS116 and BACAAM can lead to novel findings pertaining to protein stability, which can bring about new strategies for protein engineering. Basically, the comparative study of closely related amylases and the protein engineering of already existing ones are certainly important because they offer opportunities to understand the structure–function relationships of these biocatalysts.

show abstract

“…Bacterial conversion of ginsenosides has been well documented [24][25][26][27], and Bacillus sp. are known to produce a plethora of degradative enzymes [28][29][30].…”

Section: Introductionmentioning

confidence: 99%