Twisting of glycosidic bonds by hydrolases.

Carbohydr Res

Southern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, New Orleans, LA 70124-4305, USA.

Published: November 2009

Patterns of scissile bond twisting have been found in crystal structures of glycoside hydrolases (GHs) that are complexed with substrates and inhibitors. To estimate the increased potential energy in the substrates that results from this twisting, we have plotted torsion angles for the scissile bonds on hybrid Quantum Mechanics::Molecular Mechanics energy surfaces. Eight such maps were constructed, including one for alpha-maltose and three for different forms of methyl alpha-acarviosinide to provide energies for twisting of alpha-(1,4) glycosidic bonds. Maps were also made for beta-thiocellobiose and for three beta-cellobiose conformers having different glycon ring shapes to model distortions of beta-(1,4) glycosidic bonds. Different GH families twist scissile glycosidic bonds differently, increasing their potential energies from 0.5 to 9.5 kcal/mol. In general, the direction of twisting of the glycosidic bond away from the conformation of lowest intramolecular energy correlates with the position (syn or anti) of the proton donor with respect to the glycon's ring oxygen atom. This correlation suggests that glycosidic bond distortion is important for the optimal orientation of one of the glycosidic oxygen lone pairs toward the enzyme's proton donor.

Download full-text PDF

Source
http://dx.doi.org/10.1016/j.carres.2009.08.011DOI Listing

Publication Analysis

Top Keywords

glycosidic bonds
16
twisting glycosidic
8
glycosidic bond
8
proton donor
8
glycosidic
6
twisting
5
bonds
5
bonds hydrolases
4
hydrolases patterns
4
patterns scissile
4

Similar Publications

β-1,3-1,4-Glucanases have attracted significant interest because of their potential applications in various food industries. Glycoside hydrolase (GH) family 148 β-1,3-1,4-glucanases exhibit excellent thermal stability and a unique catalytic mechanism, making them particularly promising for certain food processing applications. This study investigated the module architecture enzymatic properties, catalytic mechanisms, and potential applications of a multi-domain β-1,3-1,4-glucanase (EngU) from GH family 148.

View Article and Find Full Text PDF

Comparative structural analysis of holocellulose from sugarcane bagasse, poplar, and spruce: Unraveling the interplay between structural characteristics and enhanced enzymatic hydrolysis.

Int J Biol Macromol

March 2025

Jiangsu Co-Innovation Center for Efficient Processing and Utilization of Forest Resources and International Innovation Center for Forest Chemicals and Materials, Nanjing Forestry University, Nanjing 210037, China.

This study investigated the structural recalcitrance of holocellulose from lignocellulosic biomasses (LCBs): sugarcane-bagasse (R-SCB), R-Poplar, and R-Spruce, considering their heterogeneous recalcitrance. Acidic sodium chlorite (ASC) pretreatment was employed for different time intervals (0-4 h) and extracted holocellulose samples (SCB, poplar, and spruce) with comparable lignin content (~7 %) were further alkaline-incubated (1-SCB, 1-Poplar, and 1-Spruce) with 1 % NaOH at 50 °C for 1 h. Varying enzymatic hydrolysis (EH) results indicate distinct structural heterogeneity, which was further investigated through the deconvolution of FTIR, XRD, XPS, and 13CP MAS NMR spectra, highlighting the synergistic interplay among various allomorphs of cellulose that determine the glucose yield.

View Article and Find Full Text PDF

Structural determination, immunomodulatory activity, and antitumor activity of a low-molecular-weight polysaccharide extracted from Lepista sordida.

Int J Biol Macromol

March 2025

Key Laboratory of Nanchong City of Ecological Environment Protection and Pollution Prevention in Jialing River Basin, College of Environmental Science and Engineering, China West Normal University, Nanchong 637009, China. Electronic address:

In this study, the isolation and purification of Lepista sordida polysaccharides (LS-P) were conducted, followed by an in-depth investigation of structural features and biological functions. The findings demonstrated that the backbone of LS-P comprised (1 → 6)-Glcp, (1 → 4)-D-Galp, (1 → 4)-D-Glcp, (1 → 6)-Galp, and (1 → 4,6)-Glcp, with the side chains primarily composed of terminal →2)-α-D-Glcp. The ratio of glucose to galactose was 8: 5.

View Article and Find Full Text PDF

There is a growing demand for natural and potent α-glucosidase inhibitors due to the rising prevalence of diabetes. In this study, newly identified α-glucosidase inhibitory peptides were identified from the tryptic hydrolysate of hemp seed proteins based on peptidomics and in silico analysis. A total of 424 peptides, primarily derived from four cupin-type-1 domain-containing proteins, were identified, and 13 ultimately were selected for validation based on their higher PeptideRanker scores, solubility, non-toxicity, and favorable ADMET properties.

View Article and Find Full Text PDF

is one of the most widely used plants in the Liliaceae family, renowned for its dual medicinal and edible properties. polysaccharides, as the main pharmacological active ingredient of , have various excellent physiological activities, such as antioxidant, immune enhancement, and hypoglycemic activities. Through extraction, purification, and structural analysis, the influence and mechanism of the molecular weight and glycosidic bonds of polysaccharides on the pharmacological effects, as well as their structure-activity relationship, can be explored in more detail.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!