Related Experiment Video
Updated: Jan 31, 2026

Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles
Published on: December 31, 2019
Identification, Heterologous Expression, and Characterization of a New α-Galactosidase From Geobacillus kaustophilus
1Bioengineering Department, Institute of Science, Kafkas University, Kars, Turkey.
Abstract:
α-Galactosidase enzymes have a variety of applications in numerous areas, including medicine, energy, food, feed, prebiotics, and paper pulp production. A single α-galactosidase gene was identified in the Geobacillus kaustophilus genome through the analysis of the carbohydrate-active enzymes (CAZY) database. The objective of this study was to clone, express heterologously, purify, and biochemically characterize the α-galactosidase enzyme encoded in the G. kaustophilus genome. In order to achieve this, a codon-optimized synthetic gene encoding the α-galactosidase enzyme was cloned into the pQE30 plasmid and expressed in Escherichia coli BL21 DE3 pLysS. The biochemical characterization of G. kaustophilus α-galactosidase revealed that the purified enzyme exhibited optimal activity at 40°C and pH 6.0 in citrate buffer, with demonstrable activity over a broad range of pH and temperature. Furthermore, the GKαGal enzyme exhibited a Vmax value of 41.09 U/mg and a 0.248 mM Km value towards 4-nitrophenyl-α-d-galactopyranoside (pNPGal). In essence, the produced α-galactosidase enzyme has potential applications in the degradation of lignocellulosic biomass, disaccharides production, and in medical contexts.
Related Concept Videos
Cell Specific Gene Expression
α-Alkylation of Ketones via Enolate Ions
What is Gene Expression?
Gene expression is the process in which DNA directs the synthesis of functional products, that is, proteins. Cells can regulate gene expression at various stages. It allows organisms to generate different cell types and enables cells to adapt to internal and external factors.
Genetic Information Flows from DNA to RNA to Protein
A gene is a stretch of DNA that serves as the blueprint for functional RNAs and proteins. Since DNA is made up of nucleotides and proteins consist of amino...
Factors Affecting α-Alkylation of Ketones: Choice of Base
The reaction involving bases like EtO− whose conjugate acid EtOH (pKa = 15.9) is stronger than the ketone (pKa = 19.2) results in an equilibrium mixture with higher ketone concentration. As a consequence,...
Reactions of α-Halocarbonyl Compounds: Nucleophilic Substitution
Acid-Catalyzed α-Halogenation of Aldehydes and Ketones
In the first step of the mechanism, the acid protonates the carbonyl oxygen resulting in a resonance-stabilized cation, which subsequently loses an α-hydrogen to form an enol tautomer. The C=C bond in an enol is highly nucleophilic because of the electron-donating nature of the –OH group. Consequently, the double bond attacks an electrophilic halogen to form a...

