Effect of Ca(2+) on the activity and structure of α-glucosidase: inhibition kinetics and molecular dynamics simulations.
Understanding the mechanism of inhibition of α-glucosidase (EC 3.2.1.20) is clinically important because of the involvement of this enzyme in type 2 diabetes mellitus. In this study, we conducted inhibition kinetics of α-glucosidase with Ca(2+) and 10-ns molecular dynamics simulations. We found that direct binding of Ca(2+) to the enzyme induced structural changes and inhibited enzyme activity. Ca(2+) inhibited α-glucosidase in a mixed-type reaction (Ki = 27.0 ± 2.0 mM) and directly induced the unfolding of α-glucosidase, which resulted in the exposure of hydrophobic residues. The simulations suggest that thirteen Ca(2+) ions may interact with α-glucosidase residues and that the Ca(2+) binding sites are associated with the structural changes in α-glucosidase. Our study provides insight into the mechanism of the Ca(2+)-induced structural changes in α-glucosidase and the inhibition of ligand binding. These results suggest that Ca(2+) could act as a potent inhibitor of α-glucosidase for the treatment of type 2 diabetes mellitus.
School of Preclinical Medicine, Beijing University of Chinese Medicine, 11 Beisanhuandong Road, Beijing 100029, PR China.
Xin
X
Zhang
School of Life Science, Tsinghua University, Zhongguancun Street, Beijing 100084, PR China.
Long
L
Shi
College of Life Sciences, Zhejiang Sci-Tech University, College Park, No. 2, 5th Avenue, Hangzhou 310018, PR China.
Xuan
X
Li
College of Life Sciences, Zhejiang Sci-Tech University, College Park, No. 2, 5th Avenue, Hangzhou 310018, PR China.
Qing
Q
Sheng
College of Biological and Environmental Engineering, Zhejiang University of Technology, 18 Chaowang Road, Hangzhou 310014, PR China.
Ling
L
Yao
School of Life Science, Tsinghua University, Zhongguancun Street, Beijing 100084, PR China.
Dong
D
Shen
Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, 705 Yatai Road, Jiaxing 314006, PR China.
Zhi-Rong
ZR
Lü
School of Life Science, Tsinghua University, Zhongguancun Street, Beijing 100084, PR China; Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, 705 Yatai Road, Jiaxing 314006, PR China.
Hai-Meng
HM
Zhou
Zhejiang Provincial Key Laboratory of Applied Enzymology, Yangtze Delta Region Institute of Tsinghua University, 705 Yatai Road, Jiaxing 314006, PR China.
Yong-Doo
YD
Park
Korean Bioinformation Center (KOBIC), Korea Research Institute of Bioscience and Biotechnology, Daejeon 305-806, Republic of Korea; Department of Bioinformatics, University of Sciences and Technology, Daejeon 305-350, Republic of Korea.
Jinhyuk
J
Lee
School of Preclinical Medicine, Beijing University of Chinese Medicine, 11 Beisanhuandong Road, Beijing 100029, PR China. Electronic address: z19881988@sohu.com.
Qian
Q
Zhang
D000595:Amino Acid Sequence; D001665:Binding Sites; D002118:Calcium / Q000737:chemistry*; D020134:Catalytic Domain; D003924:Diabetes Mellitus, Type 2 / Q000150:complications / Q000201:enzymology; D004791:Enzyme Inhibitors / Q000737:chemistry*; D005960:Glucosides / Q000737:chemistry; D065089:Glycoside Hydrolase Inhibitors; D006801:Humans; D007700:Kinetics; D056004:Molecular Dynamics Simulation; D008969:Molecular Sequence Data; D010024:Osteoporosis / Q000188:drug therapy / Q000209:etiology; D011485:Protein Binding; D017433:Protein Structure, Secondary; D029701:Saccharomyces cerevisiae Proteins / Q000037:antagonists & inhibitors / Q000737:chemistry*; D000520:alpha-Glucosidases / Q000737:chemistry*
D004791:Enzyme Inhibitors; D005960:Glucosides; D065089:Glycoside Hydrolase Inhibitors; D029701:Saccharomyces cerevisiae Proteins; C019502:4-nitrophenyl alpha-glucoside; D000520:alpha-Glucosidases; D002118:Calcium
Ca(2+); Inhibition kinetics; Molecular dynamics; Simulation; α-Glucosidase