Structural Characterization and Hypoglycemic Activity of a Glycoprotein Extracted from Auricularia Auricula

• Published in: Foods 2024-11, Vol.13 (23), p.3859
• Main Authors: Zhan, Qiping, Yang, Mengdie, Zhao, Xinqi, Liu, Feifei, Zhao, Liyan
• Format: Article
• Language: English
• Subjects: Amino acid composition; Amino acids; Amylases; Auricularia; Auricularia Auricula; Blood levels; Blood sugar; Carbohydrates; Chromatography; Collectors; Diabetes; Diabetes mellitus; Diabetics; Digestion; Enzymatic activity; Enzyme activity; Enzymes; Fourier transforms; Functional groups; Glucose; Glucosidase; Glycogen; Glycogens; Glycopeptides; glycoprotein; Glycoproteins; Hyperglycemia; hypoglycemic activity; Insulin; Insulin resistance; Intestine; Kinases; Metabolism; nutrient; Nutrients; Phenols; Proteins; Saliva; Spectrum analysis; Structural analysis; structural characterization; Sulfuric acid; Type 2 diabetes; Ultraviolet spectra; α-Amylase; α-Glucosidase
• ISSN: 2304-8158; 2304-8158
• DOI: 10.3390/foods13233859

Glycoproteins are special proteins and important nutrients for hypoglycemic activity. However, the structure of glycoprotein (AAG) and the stability of its hypoglycemic activity during simulated digestion (including saliva, gastral and intestine digestion) in vitro are still unknown. In this study, AAG-3 was isolated from . SDS-PAGE, UV spectrum, FTIR, amino acid composition, dichroic spectrum and SEM were used to characterize its structure. The hypoglycemic activity of AAG-3 during in vitro digestion was investigated via inhibition of α-amylase and α-glucosidase activities, as well as glucose consumption, glycogen content and related enzyme activity in insulin-resistant HepG2 cells. Structural characterization showed that AAG-3 with a Mw of 18.21 kDa had an O-type glycopeptide bond and typical functional groups of glycoproteins. AAG-3 contained 18 kinds of amino acid and many α-helixes and β-turns, and its microstructure was sheet-like. With the simulated digestion of AAG-3 in vitro, the inhibition of α-amylase and α-glucosidase activity as well as the glucose consumption, glycogen content and HK and PK enzyme activities in insulin-resistant HepG2 cells were significantly increased. Therefore, AAG-3 has a potential role in reducing blood glucose levels and improving insulin resistance and can be used as a potential micronutritional supplement for diabetic patients.