Related Experiment Video
Updated: Jul 10, 2026
13:35
Structural Biology and Analytical Chemistry Approaches for Characterizing C-Glycoside Metabolic Enzymes in Human Gut Microbiota
Published on: May 23, 2025
Functional and structural differences between isoflavonoid beta-glycosidases from Dalbergia sp
Phimonphan Chuankhayan1, Thipwarin Rimlumduan, Waraporn Tantanuch
1Schools of Biochemistry and Chemistry, Institute of Science, Suranaree University of Technology, Nakhon Ratchasima 30000, Thailand.
Archives of Biochemistry and Biophysics
|November 14, 2007
Summary
Dalbergia nigrescens beta-glucosidase (Dnbglu2) efficiently hydrolyzes specific isoflavonoid diglycosides. Mutating Dalbergia cochinchinensis beta-glucosidase (dalcochinase) showed limited improvement, suggesting other factors influence enzyme activity.
Area of Science:
- Biochemistry
- Enzymology
- Plant Science
Background:
- Isoflavonoid beta-glucosidases from Dalbergia species exhibit varying substrate specificities.
- Dalbergia nigrescens and Dalbergia cochinchinensis possess distinct beta-glucosidases with differing hydrolytic efficiencies.
Purpose of the Study:
- To clone and characterize a beta-glucosidase from Dalbergia nigrescens (Dnbglu2).
- To compare the substrate specificity of Dnbglu2 with that of Dalbergia cochinchinensis beta-glucosidase (dalcochinase).
- To investigate the role of specific amino acid residues in the substrate binding and catalytic efficiency of these enzymes.
Main Methods:
- Cloning of a cDNA encoding a beta-glucosidase from D. nigrescens seeds.
- Expression and purification of the recombinant Dnbglu2 protein in Pichia pastoris.
- Enzymatic assays to determine the catalytic efficiency (k(cat)/K(m)) of Dnbglu2 and mutated dalcochinase towards specific isoflavonoid glycosides.
Main Results:
- Dnbglu2 demonstrated significantly higher catalytic efficiency towards D. nigrescens natural substrates (dalpatein and dalnigrein diglycosides) compared to dalcochinase's substrate.
- Site-directed mutagenesis of dalcochinase at positions A454S and E455G resulted in modest increases in activity towards the D. nigrescens substrates.
- The activity of the double-mutant dalcochinase remained substantially lower than that of Dnbglu2, indicating the involvement of other structural determinants.
Conclusions:
- Dnbglu2 is a highly efficient enzyme for hydrolyzing specific isoflavonoid diglycosides found in Dalbergia species.
- The investigated amino acid substitutions in dalcochinase are not solely responsible for the differences in substrate specificity observed between the two enzymes.
- Further research is needed to elucidate the complete structural basis for the distinct substrate preferences of these Dalbergia beta-glucosidases.
Related Concept Videos
02:34Structural Isomerism
Isomerism in Complexes
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
Isomers are different chemical species that have the same chemical formula. Structural isomerism of coordination compounds can be divided into two subcategories, the linkage isomers and coordination-sphere isomers.
Linkage isomers occur when the coordination compound contains a ligand that can bind to the transition metal center through two different atoms. For example, the CN− ligand can bind through the carbon atom or through the nitrogen atom. Similarly, SCN− can be...
01:15Cellulose and Pectic Polysaccharides
Every plant cell has a cell wall that protects the cell, provides structural support, and gives the cell shape. Cellulose, the main structural component of the plant cell wall, makes up over 30% of plant matter. It is the most abundant organic compound on earth. Cellulose is an unbranched polysaccharide composed of linear chains of glucose molecules linked by β (1→4) glycosidic bonds.
As a cell matures, its cell wall specializes according to its type. For example, the parenchyma cells of...
As a cell matures, its cell wall specializes according to its type. For example, the parenchyma cells of...
02:21Globular and Fibrous Proteins
Many proteins can be classified into two distinct subtypes - globular or fibrous. These two types differ in their shapes and solubilities.
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...
Globular proteins are also known as spheroproteins and typically are approximately round in shape. They contain a mix of amino acid types and contain differing sequences in their primary structures. Globular proteins have many different functions, such as enzymes, cellular messengers, and molecular transporters. These roles often require the proteins to be...