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Author Liu, Juanjuan ♦ Zhang, Xuecheng ♦ Fang, Zemin ♦ Fang, Wei ♦ Peng, Hui ♦ Xiao, Yazhong
Source World Health Organization (WHO)-Global Index Medicus
Content type Text
Publisher Elsevier
File Format HTM / HTML
Language English
Difficulty Level Medium
Subject Domain (in DDC) Natural sciences & mathematics ♦ Chemistry & allied sciences ♦ Life sciences; biology ♦ Physiology & related subjects ♦ Biochemistry ♦ Natural history of organisms ♦ Microorganisms, fungi & algae ♦ Technology ♦ Medicine & health ♦ Human physiology ♦ Pharmacology and therapeutics ♦ Diseases ♦ Chemical engineering ♦ Manufacture for specific uses ♦ Precision instruments & other devices
Subject Domain (in MeSH) Bacteria ♦ Organisms ♦ Enzymes and Coenzymes ♦ Chemicals and Drugs ♦ Investigative Techniques ♦ Analytical, Diagnostic and Therapeutic Techniques and Equipment ♦ Physical Phenomena ♦ Chemical Phenomena ♦ Biological Sciences ♦ Natural Science Disciplines ♦ Physical Sciences
Subject Keyword Discipline Biomedical Engineering ♦ Discipline Microbiology ♦ Metagenomics ♦ Mutagenesis, Site-directed ♦ Beta-glucosidase ♦ Metabolism ♦ Amino Acid Substitution ♦ Enzyme Stability ♦ Kinetics ♦ Paenibacillus ♦ Enzymology ♦ Substrate Specificity ♦ Chemistry ♦ Genetics ♦ Journal Article ♦ Research Support, Non-u.s. Gov't
Abstract Bgl1B (ACY09072) is a new GH1 family ß-glucosidase derived from a marine microbial metagenomic library. In our previous study, the activity of recombinant Bgl1B was competitively inhibited by glucose with an IC50 value of 30 mM. Based on amino acids sequence alignment with other GH1 ß-glucosidases, including BglB from Paenibacillus polymyxa whose structure has been solved, the 184th and 409th residues of Bgl1B were suggested to be key residues relating to glucose tolerance or other properties. The putative role of the two residues of Bgl1B was investigated by site-directed mutagenesis by replacing His184 and Leu409 with Phe and Glu, respectively. Biochemical characterization data indicated that the mutations had little influence on the enzyme properties. However, in comparison with wild-type Bgl1B, the mutant H184F exhibited lower stability at all tested temperatures and pHs, while L409E exhibited higher stability. Particularly, when using 4-Nitrophenyl-ß-D-glucopyranoside (pNPG) as substrate, the mutant H184F exhibited much better glucose tolerance, with a K(i) of 76.9 mM, than L409E and wild-type Bgl1B (17.2 mM and 14.9 mM, respectively). These results indicated that the 184th residue might play an important role in the glucose tolerance of Bgl1B.
Description Country affiliation: China
Author Affiliation: Liu J ( School of Life Sciences, Anhui University, Hefei, Anhui 230039, China.)
ISSN 13891723
Educational Role Student ♦ Teacher
Age Range above 22 year
Educational Use Reading ♦ Research ♦ Self Learning
Interactivity Type Expositive
Education Level UG and PG
Learning Resource Type Article
Publisher Date 2011-11-01
Publisher Place Japan
e-ISSN 13474421
Journal Journal of Bioscience and Bioengineering
Volume Number 112
Issue Number 5


Source: WHO-Global Index Medicus