title: Effects of L-malic acid on alpha-glucosidase: inhibition kinetics and computational molecular dynamics simulations.
abstract: The inhibitory effect of L-malic acid (MA) on alpha-glucosidase (EC 3.2.1.20) was investigated by combination study between inhibition kinetics and computational simulations. The results from the serial kinetics demonstrated that MA could directly inactivate the enzyme activity in a dose-dependent manner and a typical non-competitive type, as well as in a fast inactivate process without detectable time course. The tertiary conformation study with an application of spectrofluorimetry showed that MA modulated the tertiary structural conformation of alpha-glucosidase both on the overall and on regional active site pocket, which monitored by red-shift intrinsic fluorescence peak with decreases intensities, and the significant intensity increasing of 1-anilinonaphthalene-8-sulfonate (ANS)-binding fluorescence, respectively. To have more insight, we also adapted the computational molecular dynamics (MD) simulations. The results showed that MA was located in the entrance of active pocket for the catalytic reaction and blocked the passage of substrate. It confirmed that MA inhibits as a non-competitive type, not direct docking to the glucose binding site. Our study provides important molecular mechanisms to figure out alpha-glucosidase inhibition that might associate to development of type 2 diabetes mellitus drug.
authors.affiliation: College of Biology and Science, Sichuan Agriculture University, Chengdu, 611130, People's Republic of China, goulin2015@hotmail.com.
authors.forename: Lin
authors.initials: L
authors.lastname: Gou
authors.forename: Yi
authors.initials: Y
authors.lastname: Zhan
authors.forename: Jinhyuk
authors.initials: J
authors.lastname: Lee
authors.forename: Xuan
authors.initials: X
authors.lastname: Li
authors.forename: Zhi-Rong
authors.initials: ZR
authors.lastname: Lü
authors.forename: Hai-Meng
authors.initials: HM
authors.lastname: Zhou
authors.forename: Hang
authors.initials: H
authors.lastname: Lu
authors.forename: Xi-Yao
authors.initials: XY
authors.lastname: Wang
authors.forename: Yong-Doo
authors.initials: YD
authors.lastname: Park
authors.forename: Jun-Mo
authors.initials: JM
authors.lastname: Yang
mesh_terms: D000817:Anilino Naphthalenesulfonates; D020134:Catalytic Domain; D005456:Fluorescent Dyes; D065089:Glycoside Hydrolase Inhibitors / Q000737:chemistry*; D007004:Hypoglycemic Agents / Q000737:chemistry*; D007700:Kinetics; D008293:Malates / Q000737:chemistry*; D062105:Molecular Docking Simulation; D056004:Molecular Dynamics Simulation; D011485:Protein Binding; D011487:Protein Conformation; D012441:Saccharomyces cerevisiae / Q000737:chemistry / Q000201:enzymology; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors* / Q000737:chemistry; D013816:Thermodynamics; D000520:alpha-Glucosidases / Q000737:chemistry*
chemical_list: C515594:8-anilino-1-naphthalenesulfonic acid; D000817:Anilino Naphthalenesulfonates; D005456:Fluorescent Dyes; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D008293:Malates; D029701:Saccharomyces cerevisiae Proteins; C030298:malic acid; D000520:alpha-Glucosidases