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Inhibition of individual subunits of maltase‐glucoamylase and sucrase‐isomaltase by polyphenols (1045.26)
Author(s) -
Simsek Meric,
QuezadaCalvillo Roberto,
Nichols Buford,
Hamaker Bruce
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.1045.26
Subject(s) - chemistry , biochemistry , maltase , gallic acid , caffeic acid , polyphenol , food science , ic50 , enzyme , antioxidant , in vitro
Some polyphenols inhibit the activities of the four subunits of intestinal α‐glucosidases, maltase‐glucoamylase (Mgam) and sucrase‐isomaltase (Si). The use of polyphenols as modulators of the rate of glucose release from starchy foods has been proposed for the treatment of metabolic diseases such as diabetes. The inhibitory properties of polyphenols on individual C‐terminal (Ct) and N‐terminal (Nt) subunits of each Mgam and Si have not been studied, limiting their use in a rational way. Our objective was to determine the inhibitory properties of caffeic acid, gallic acid, (+)‐catechin hydrate (CH), chlorogenic acid (CA) and (‐) epigallocatechin gallate (EGCG) on maltase activity of the recombinant individual subunits. Activities were measured by Tris glucose‐oxidase method, and the inhibition reactions were performed in presence of 2.1‐16.67 mM maltose and 0‐667 µM of each individual polyphenol. All studied polyphenols showed mixed type inhibition. EGCG and CA showed the lowest inhibition constants (Ki1 and Ki2) for Ct‐Mgam and Ct‐Si, with values in the range of 3‐28 µM. The highest inhibition capacity for Nt‐Mgam and Nt‐Si was shown by CH in the range of 20.4‐97.2 µM. EGCG and CA can be effective in controlling glucose release by inhibiting the highly active Ct‐Mgam and Ct‐Si α‐glucosidic activities. The selective inhibition of Ct and Nt subunits opens the possibility for using specific polyphenols or their combinations to modulate the functions of Mgam and Si for the digestion of starches. Grant Funding Source : Supported by CONACyT Mexico