The increasing prevalence of diabetes has accelerated the search for new drugs derived from natural sources. To define the functional features of two such families of compounds, the flavonols and the ethyl caffeates, we have determined the high-resolution structures of representative inhibitors in complex with human pancreatic alpha-amylase. Myricetin binds at the active site and interacts directly with the catalytic residues despite its bulky planar nature. Notably, it reduces the normal conformational flexibility of the adjacent substrate binding cleft. In contrast, bound ethyl caffeate acts by disordering precisely those polypeptide chain segments that make up the active site binding cleft. It also operates from binding sites far removed from the active site, a property not observed in any other class of human alpha-amylase inhibitor studied to date. Given the current inadequacy of drugs directed at diabetes, the use of optimized flavonols and ethyl caffeates may present an alternative therapeutic route.
Order and Disorder: The Differential Structural Impacts of Myricetin and Ethyl Caffeate on Human Amylase, an Anti-Diabetic Target.,Williams LK, Li C, Withers SG, Brayer GD J Med Chem. 2012 Oct 10. PMID:23050660
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
↑ Williams LK, Li C, Withers SG, Brayer GD. Order and Disorder: The Differential Structural Impacts of Myricetin and Ethyl Caffeate on Human Amylase, an Anti-Diabetic Target. J Med Chem. 2012 Oct 10. PMID:23050660 doi:http://dx.doi.org/10.1021/jm301273u