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Liao SM, Shen NK, Liang G, Lu B, Lu ZL, Peng LX, Zhou F, Du LQ, Wei YT, Zhou GP, Huang RB. Inhibition of α-amylase Activity by Zn2+: Insights from Spectroscopy and Molecular Dynamics Simulations. Med Chem 2019; 15:510-520. [DOI: 10.2174/1573406415666181217114101] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2018] [Revised: 10/23/2018] [Accepted: 12/12/2018] [Indexed: 02/08/2023]
Abstract
Background:Inhibition of α-amylase activity is an important strategy in the treatment of diabetes mellitus. An important treatment for diabetes mellitus is to reduce the digestion of carbohydrates and blood glucose concentrations. Inhibiting the activity of carbohydrate-degrading enzymes such as α-amylase and glucosidase significantly decreases the blood glucose level. Most inhibitors of α-amylase have serious adverse effects, and the α-amylase inactivation mechanisms for the design of safer inhibitors are yet to be revealed.Objective:In this study, we focused on the inhibitory effect of Zn2+ on the structure and dynamic characteristics of α-amylase from Anoxybacillus sp. GXS-BL (AGXA), which shares the same catalytic residues and similar structures as human pancreatic and salivary α-amylase (HPA and HSA, respectively).Methods:Circular dichroism (CD) spectra of the protein (AGXA) in the absence and presence of Zn2+ were recorded on a Chirascan instrument. The content of different secondary structures of AGXA in the absence and presence of Zn2+ was analyzed using the online SELCON3 program. An AGXA amino acid sequence similarity search was performed on the BLAST online server to find the most similar protein sequence to use as a template for homology modeling. The pocket volume measurer (POVME) program 3.0 was applied to calculate the active site pocket shape and volume, and molecular dynamics simulations were performed with the Amber14 software package.Results:According to circular dichroism experiments, upon Zn2+ binding, the protein secondary structure changed obviously, with the α-helix content decreasing and β-sheet, β-turn and randomcoil content increasing. The structural model of AGXA showed that His217 was near the active site pocket and that Phe178 was at the outer rim of the pocket. Based on the molecular dynamics trajectories, in the free AGXA model, the dihedral angle of C-CA-CB-CG displayed both acute and planar orientations, which corresponded to the open and closed states of the active site pocket, respectively. In the AGXA-Zn model, the dihedral angle of C-CA-CB-CG only showed the planar orientation. As Zn2+ was introduced, the metal center formed a coordination interaction with H217, a cation-π interaction with W244, a coordination interaction with E242 and a cation-π interaction with F178, which prevented F178 from easily rotating to the open state and inhibited the activity of the enzyme.Conclusion:This research may have uncovered a subtle mechanism for inhibiting the activity of α-amylase with transition metal ions, and this finding will help to design more potent and specific inhibitors of α-amylases.
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Affiliation(s)
- Si-Ming Liao
- Department of Bioengineering, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Nai-Kun Shen
- School of Marine Sciences and Biotechnology, Guangxi University for Nationalities, Nanning, Guangxi, 530008, China
| | - Ge Liang
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, China
| | - Bo Lu
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, China
| | - Zhi-Long Lu
- Department of Bioengineering, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Li-Xin Peng
- Department of Bioengineering, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Feng Zhou
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, China
| | - Li-Qin Du
- Department of Bioengineering, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Yu-Tuo Wei
- Department of Bioengineering, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
| | - Guo-Ping Zhou
- State Key Laboratory of Non-Food Biomass and Enzyme Technology, Guangxi Academy of Sciences, Nanning, Guangxi, 530007, China
| | - Ri-Bo Huang
- Department of Bioengineering, College of Life Science and Technology, Guangxi University, Nanning, Guangxi, 530004, China
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Gondim ACS, Romero-Canelón I, Sousa EHS, Blindauer CA, Butler JS, Romero MJ, Sanchez-Cano C, Sousa BL, Chaves RP, Nagano CS, Cavada BS, Sadler PJ. The potent anti-cancer activity of Dioclea lasiocarpa lectin. J Inorg Biochem 2017; 175:179-189. [PMID: 28756174 DOI: 10.1016/j.jinorgbio.2017.07.011] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2017] [Revised: 07/03/2017] [Accepted: 07/10/2017] [Indexed: 02/07/2023]
Abstract
The lectin DLasiL was isolated from seeds of the Dioclea lasiocarpa collected from the northeast coast of Brazil and characterized for the first time by mass spectrometry, DNA sequencing, inductively coupled plasma-mass spectrometry, electron paramagnetic resonance, and fluorescence spectroscopy. The structure of DLasiL lectin obtained by homology modelling suggested strong conservation of the dinuclear Ca/Mn and sugar-binding sites, and dependence of the solvent accessibility of tryptophan-88 on the oligomerisation state of the protein. DLasiL showed highly potent (low nanomolar) antiproliferative activity against several human carcinoma cell lines including A2780 (ovarian), A549 (lung), MCF-7 (breast) and PC3 (prostate), and was as, or more, potent than the lectins ConBr (Canavalia brasiliensis), ConM (Canavalia maritima) and DSclerL (Dioclea sclerocarpa) against A2780 and PC3 cells. Interestingly, DLasiL lectin caused a G2/M arrest in A2780 cells after 24h exposure, activating caspase 9 and delaying the on-set of apoptosis. Confocal microscopy showed that fluorescently-labelled DLasiL localized around the nuclei of A2780 cells at lectin doses of 0.5-2× IC50 and gave rise to enlarged nuclei and spreading of the cells at high doses. These data reveal the interesting antiproliferative activity of DLasiL lectin, and suggest that further investigations to explore the potential of DLasiL as a new anticancer agent are warranted.
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Affiliation(s)
- Ana C S Gondim
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60455-760 Fortaleza, Ceará, Brazil; Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; Department of Organic and Inorganic Chemistry, Federal University of Ceará, 60455-900 Fortaleza, Ceará, Brazil
| | | | - Eduardo H S Sousa
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK; Department of Organic and Inorganic Chemistry, Federal University of Ceará, 60455-900 Fortaleza, Ceará, Brazil
| | | | - Jennifer S Butler
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | - María J Romero
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK
| | | | - Bruno L Sousa
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60455-760 Fortaleza, Ceará, Brazil
| | - Renata P Chaves
- Department of Fishing and Engineering, Federal University of Ceará, 60455-900 Fortaleza, Ceará, Brazil
| | - Celso S Nagano
- Department of Fishing and Engineering, Federal University of Ceará, 60455-900 Fortaleza, Ceará, Brazil
| | - Benildo S Cavada
- Department of Biochemistry and Molecular Biology, Federal University of Ceará, 60455-760 Fortaleza, Ceará, Brazil.
| | - Peter J Sadler
- Department of Chemistry, University of Warwick, Coventry CV4 7AL, UK.
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Surya S, Geethanandan K, Sadasivan C, Haridas M. Gallic acid binding to Spatholobus parviflorus lectin provides insight to its quaternary structure forming. Int J Biol Macromol 2016; 91:696-702. [PMID: 27283232 DOI: 10.1016/j.ijbiomac.2016.06.010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2016] [Revised: 06/02/2016] [Accepted: 06/05/2016] [Indexed: 11/25/2022]
Abstract
Therapeutic effects of gallic acid (GA) have already been extensively studied. However, its interaction with lectins has not gained much attention. It is of interest to validate the binding profile of GA with Spatholobus parviflorus seed lectin. A combination of Isothermal Titration Calorimetry (ITC), haemagglutination assay and molecular docking was applied on SPL-GA interaction. ITC results showed four binding sites, stoichiometry, n=4, irrespective of the ratio of SPL:GA taken for titration. Difference among the four binding sites of a single molecule of SPL with regard to GA binding kinetic parameters was consistently varying. Similarly, the glide scores obtained for GA in the four different binding clefts of SPL were also conformed to the ITC. The binding of GA on SPL without affecting its sugar binding property could be considered as a boon for glycobiological research. From the presented studies, it could be proposed that the SPL-GA interactions may facilitate drug delivery by specific targeting/attachment by profiling of cell-surface glycans, followed by controlled release of drugs.
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Affiliation(s)
- Sukumaran Surya
- Inter University Centre for Bioscience and Department of Biotechnology and Microbiology, Kannur University, Thalassery Campus, Kannur 670661, India
| | - Krishnan Geethanandan
- Inter University Centre for Bioscience and Department of Biotechnology and Microbiology, Kannur University, Thalassery Campus, Kannur 670661, India
| | - Chittalakkottu Sadasivan
- Inter University Centre for Bioscience and Department of Biotechnology and Microbiology, Kannur University, Thalassery Campus, Kannur 670661, India
| | - Madhathilkovilakathu Haridas
- Inter University Centre for Bioscience and Department of Biotechnology and Microbiology, Kannur University, Thalassery Campus, Kannur 670661, India.
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