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Bhaumik S, Sarkar A, Debnath S, Debnath B, Ghosh R, Zaki ME, Al-Hussain SA. α-Glucosidase inhibitory potential of Oroxylum indicum using molecular docking, molecular dynamics, and in vitro evaluation. Saudi Pharm J 2024; 32:102095. [PMID: 38766274 PMCID: PMC11101736 DOI: 10.1016/j.jsps.2024.102095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 05/01/2024] [Indexed: 05/22/2024] Open
Abstract
Background According to the International Diabetes Federation, there will be 578 million individuals worldwide with diabetes by 2030 and 700 million by 2045. One of the promising drug targets to fight diabetes is α-glucosidase (AG), and its inhibitors may be used to manage diabetes by reducing the breakdown of complex carbohydrates into simple sugars. The study aims to identify and validate potential AG inhibitors in natural sources to combat diabetes. Methods Computational techniques such as structure-based virtual screening and molecular dyncamic simulation were employed to predict potential AG inhibitors from compounds of Oroxylum indicum. Finally, in silico results were validated by in vitro analysis using n-butanol fraction of crude methanol extracts. Results The XP glide scores of top seven hits OI_13, OI_66, OI_16, OI_44, OI_43, OI_20, OI_78 and acarbose were -14.261, -13.475, -13.074, -13.045, -12.978, -12.659, -12.354 and -12.296 kcal/mol, respectively. These hits demonstrated excellent binding affinity towards AG, surpassing the known AG inhibitor acarbose. The MM-GBSA dG binding energies of OI_13, OI_66, and acarbose were -69.093, -62.950, and -53.055 kcal/mol, respectively. Most of the top hits were glycosides, indicating that active compounds lie in the n-butanol fraction of the extract. The IC50 value for AG inhibition by n-butanol fraction was 248.1 μg/ml, and for that of pure acarbose it was 89.16 μg/ml. The predicted oral absorption rate in humans for the top seven hits was low like acarbose, which favors the use of these compounds as anti-diabetes in the small intestine. Conclusion In summary, the study provides promising insights into the use of natural compounds derived from O. indicum as potential AG inhibitors to manage diabetes. However, further research, including clinical trials and pharmacological studies, would be necessary to validate their efficacy and safety before clinical use.
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Affiliation(s)
- Samhita Bhaumik
- Department of Chemistry, Women’s College, Agartala, Tripura 799001, India
| | - Alekhya Sarkar
- Department of Forestry and Biodiversity, Tripura University, Suryamaninagar, Tripura, India
| | - Sudhan Debnath
- Department of Chemistry, Netaji Subhash Mahavidyalaya, Udaipur, Tripura 799 114, India
| | - Bimal Debnath
- Department of Forestry and Biodiversity, Tripura University, Suryamaninagar, Tripura, India
| | - Rajat Ghosh
- In Silico Drug Design Lab., Department of Pharmacy, Tripura University, Suryamaninagar, Tripura, India
| | - Magdi E.A. Zaki
- Department of Chemistry, Faculty of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh 11623, Saudi Arabia
| | - Sami A. Al-Hussain
- Department of Chemistry, Faculty of Science, Imam Mohammad Ibn Saud Islamic University, Riyadh 11623, Saudi Arabia
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2
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Li J, Mui JWY, da Silva BM, Pires DEV, Ascher DB, Madiedo Soler N, Goddard-Borger ED, Williams SJ. A Broad-Spectrum α-Glucosidase of Glycoside Hydrolase Family 13 from Marinovum sp., a Member of the Roseobacter Clade. Appl Biochem Biotechnol 2024:10.1007/s12010-023-04820-3. [PMID: 38180643 DOI: 10.1007/s12010-023-04820-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/19/2023] [Indexed: 01/06/2024]
Abstract
Glycoside hydrolases (GHs) are a diverse group of enzymes that catalyze the hydrolysis of glycosidic bonds. The Carbohydrate-Active enZymes (CAZy) classification organizes GHs into families based on sequence data and function, with fewer than 1% of the predicted proteins characterized biochemically. Consideration of genomic context can provide clues to infer possible enzyme activities for proteins of unknown function. We used the MultiGeneBLAST tool to discover a gene cluster in Marinovum sp., a member of the marine Roseobacter clade, that encodes homologues of enzymes belonging to the sulfoquinovose monooxygenase pathway for sulfosugar catabolism. This cluster lacks a gene encoding a classical family GH31 sulfoquinovosidase candidate, but which instead includes an uncharacterized family GH13 protein (MsGH13) that we hypothesized could be a non-classical sulfoquinovosidase. Surprisingly, recombinant MsGH13 lacks sulfoquinovosidase activity and is a broad-spectrum α-glucosidase that is active on a diverse array of α-linked disaccharides, including maltose, sucrose, nigerose, trehalose, isomaltose, and kojibiose. Using AlphaFold, a 3D model for the MsGH13 enzyme was constructed that predicted its active site shared close similarity with an α-glucosidase from Halomonas sp. H11 of the same GH13 subfamily that shows narrower substrate specificity.
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Affiliation(s)
- Jinling Li
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Janice W-Y Mui
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Bruna M da Silva
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Melbourne, Victoria, 3004, Australia
- School of Computing and Information Systems, University of Melbourne, Parkville, Victoria, 3010, Australia
| | - Douglas E V Pires
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Melbourne, Victoria, 3004, Australia
- School of Computing and Information Systems, University of Melbourne, Parkville, Victoria, 3010, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, 4072, Australia
| | - David B Ascher
- Computational Biology and Clinical Informatics, Baker Heart and Diabetes Institute, Melbourne, Victoria, 3004, Australia
- School of Chemistry and Molecular Biosciences, University of Queensland, St Lucia, Queensland, 4072, Australia
| | - Niccolay Madiedo Soler
- ACRF Chemical Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Ethan D Goddard-Borger
- ACRF Chemical Biology Division, The Walter and Eliza Hall Institute of Medical Research, Parkville, Victoria, 3052, Australia
- Department of Medical Biology, University of Melbourne, Parkville, Victoria, 3052, Australia
| | - Spencer J Williams
- School of Chemistry and Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, 3010, Australia.
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Abdelrahim MS, Abdel-Baky AM, Bayoumi SAL, Backheet EY. Antioxidant and antidiabetic flavonoids from the leaves of Dypsis pembana (H.E.Moore) Beentje & J.Dransf., Arecaceae: in vitro and molecular docking studies. BMC Complement Med Ther 2023; 23:440. [PMID: 38053195 DOI: 10.1186/s12906-023-04287-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Accepted: 11/29/2023] [Indexed: 12/07/2023] Open
Abstract
BACKGROUND Oxidative stress and diabetes are medical conditions that have a growing prevalence worldwide, significantly impacting our bodies. Thus, it is essential to develop new natural antioxidant and antidiabetic agents. Dypsis pembana (H.E.Moore) Beentje & J.Dransf (DP) is an ornamental palm of the family Arecaceae. This study aimed to broaden the understanding of this plant's biological properties by evaluating its in vitro antioxidant and antidiabetic activities. METHODS The in vitro antioxidant activities of the crude extract, fractions, and selected isolates were evaluated by DPPH method. While the in vitro antidiabetic activities of these samples were evaluated by assessing the degree of inhibition of α-glucosidase. Additionally, molecular docking analysis was performed to investigate the interactions of tested compounds with two potential targets, the cytochrome c peroxidase and alpha glucosidase. RESULTS The crude extract displayed the highest antioxidant activity (IC50 of 11.56 µg/ml), whereas among the fractions, the EtOAc fraction was the most potent (IC50 of 14.20 µg/ml). Among tested compounds, isoquercetrin (10) demonstrated the highest potency, with an IC50 value of 3.30 µg/ml, followed by rutin (8) (IC50 of 3.61 µg/ml). Regarding antidiabetic activity, the EtOAc (IC50 of 60.4 µg/ml) and CH2Cl2 fractions (IC50 of 214.9 µg/ml) showed activity, while the other fractions did not demonstrate significant antidiabetic effects. Among tested compounds, kaempferol-3-O-neohesperidoside (9) showed the highest antidiabetic activity, with an IC50 value of 18.38 µg/ml, followed by kaempferol (4) (IC50 of 37.19 µg/ml). These experimental findings were further supported by molecular docking analysis, which revealed that isoquercetrin and kaempferol-3-O-neohesperidoside exhibited strong enzyme-binding affinities to the studied enzyme targets. This analysis provided insights into the structure-activity relationships among the investigated flavonol-O-glycosides. CONCLUSION The biological and computational findings revealed that isoquercetrin and kaempferol-3-O-neohesperidoside have potential as lead compounds for inhibiting cytochrome c peroxidase and alpha glucosidase enzymes, respectively.
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Affiliation(s)
- Mohamed S Abdelrahim
- Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut, 71526, Egypt.
| | - Afaf M Abdel-Baky
- Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut, 71526, Egypt
| | - Soad A L Bayoumi
- Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut, 71526, Egypt
| | - Enaam Y Backheet
- Department of Pharmacognosy, Faculty of Pharmacy, Assiut University, Assiut, 71526, Egypt
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4
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Cao W, Watanabe R, Ishii Y, Kirimura K. Enzymatic and selective production of alkyl α-d-glucopyranosides by the α-glucosyl transfer enzyme derived from Xanthomonas campestris WU-9701. J Biosci Bioeng 2023; 136:347-352. [PMID: 37748981 DOI: 10.1016/j.jbiosc.2023.08.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/18/2023] [Accepted: 08/30/2023] [Indexed: 09/27/2023]
Abstract
Several alkyl glucosides exhibit various bioactivities. 1-Octyl β-d-glucopyranoside produced by organic synthesis is used as a nonionic surfactant. However, no convenient method has been developed for the selective production of alkyl α-glucosides (α-AGs), such as 1-octyl α-d-glucopyranoside (α-OG). Therefore, we developed a simple method for selective production of α-AGs using the glucosyl transfer enzyme XgtA, (E.C. 3.2.1.20), derived from Xanthomonas campestris WU-9701. When 0.80 M alkyl alcohol and 2.5 units XgtA were incubated in 2.0 mL of 30 mM HEPES-NaOH buffer (pH 8.0) containing 1.2 M maltose at 45 °C, a specific α-AG corresponding to each alkyl alcohol (C2-C10) was detected. Under the standard conditions, we examined the selective production of α-OG from 1-octanol and maltose using XgtA. The reaction product was isolated and identified as α-OG via 1H nuclear magnetic resonance and nuclear overhauser effect spectroscopy analyses. No other glucosylated products, such as maltotriose, were detected in the reaction mixture. Under the standard conditions at 45 °C for 96 h, 243 mM α-OG (71 g/L) was produced in one batch production. Moreover, the addition of glucose isomerase to the reaction mixture decreased the concentration of glucose released via the reaction and increased the amount of α-OG produced; 359 mM α-OG (105 g/L) was maximally produced at 96 h. In conclusion, this study demonstrates the selective production of α-AGs using a simple enzymatic reaction, and XgtA has the potential to selectively produce various α-AGs.
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Affiliation(s)
- Wei Cao
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Risa Watanabe
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Yoshitaka Ishii
- Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan
| | - Kohtaro Kirimura
- Department of Applied Chemistry, Faculty of Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan; Waseda Research Institute for Science and Engineering, Waseda University, 3-4-1 Ohkubo, Shinjuku-ku, Tokyo 169-8555, Japan.
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5
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Esmaili S, Ebadi A, Khazaei A, Ghorbani H, Faramarzi MA, Mojtabavi S, Mahdavi M, Najafi Z. Novel Pyrano[3,2- c]quinoline-1,2,3-triazole Hybrids as Potential Anti-Diabetic Agents: In Vitro α-Glucosidase Inhibition, Kinetic, and Molecular Dynamics Simulation. ACS OMEGA 2023; 8:23412-23424. [PMID: 37426262 PMCID: PMC10324058 DOI: 10.1021/acsomega.3c00133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Accepted: 05/30/2023] [Indexed: 07/11/2023]
Abstract
In this study, a novel series of pyrano[3,2-c]quinoline-1,2,3-triazole hybrids 8a-o were synthesized and evaluated against the α-glucosidase enzyme. All compounds showed significant in vitro inhibitory activity (IC50 values of 1.19 ± 0.05 to 20.01 ± 0.02 μM) compared to the standard drug acarbose (IC50 = 750.0 μM). Among them, 2-amino-4-(3-((1-benzyl-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-5-oxo-5,6-dihydro-4H-pyrano[3,2-c]quinoline-3-carbonitrile (compound 8k) demonstrated the best inhibitory effect toward α-glucosidase (IC50 = 1.19 ± 0.05 μM) with a competitive pattern of inhibition. Since compound 8k was synthesized as a racemic mixture, molecular docking and dynamics simulations were performed on R- and S-enantiomers of compound 8k. Based on the molecular docking results, both R- and S-enantiomers of compound 8k displayed significant interactions with key residues including catalytic triad (Asp214, Glu276, and Asp349) in the enzyme active site. However, an in silico study indicated that S- and R-enantiomers were inversely located in the enzyme active site. The R-enantiomer formed a more stable complex with a higher binding affinity to the active site of α-glucosidase than that of the S- enantiomer. The benzyl ring in the most stable complex ((R)-compound 8k) was located in the bottom of the binding site and interacted with the enzyme active site, while the pyrano[3,2-c]quinoline moiety occupied the high solvent accessible entrance of the active site. Thus, the synthesized pyrano[3,2-c]quinoline-1,2,3-triazole hybrids seem to be promising scaffolds for the development of novel α-glucosidase inhibitors.
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Affiliation(s)
- Soheila Esmaili
- Department
of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran
| | - Ahmad Ebadi
- Department
of Medicinal Chemistry, School of Pharmacy, Medicinal Plants and Natural
Products Research Center, Hamadan University
of Medical Sciences, Hamadan 6517838678, Iran
| | - Ardeshir Khazaei
- Department
of Organic Chemistry, Faculty of Chemistry, Bu-Ali Sina University, Hamedan 6517838683, Iran
| | - Hamideh Ghorbani
- Department
of Medicinal Chemistry, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan 6517838678, Iran
| | - Mohammad Ali Faramarzi
- Department
of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology
Research Center, Tehran University of Medical
Sciences, Tehran 1417614411, Iran
| | - Somayeh Mojtabavi
- Department
of Pharmaceutical Biotechnology, Faculty of Pharmacy and Biotechnology
Research Center, Tehran University of Medical
Sciences, Tehran 1417614411, Iran
| | - Mohammad Mahdavi
- Endocrinology
and Metabolism Research Center, Endocrinology and Metabolism Clinical
Sciences Institute, Tehran University of
Medical Sciences, Tehran 1416753955, Iran
| | - Zahra Najafi
- Department
of Medicinal Chemistry, School of Pharmacy, Hamadan University of Medical Sciences, Hamadan 6517838678, Iran
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Auiewiriyanukul W, Saburi W, Ota T, Yu J, Kato K, Yao M, Mori H. Alteration of Substrate Specificity and Transglucosylation Activity of GH13_31 α-Glucosidase from Bacillus sp. AHU2216 through Site-Directed Mutagenesis of Asn258 on β→α Loop 5. Molecules 2023; 28:molecules28073109. [PMID: 37049872 PMCID: PMC10096246 DOI: 10.3390/molecules28073109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Revised: 03/28/2023] [Accepted: 03/29/2023] [Indexed: 04/03/2023] Open
Abstract
α-Glucosidase catalyzes the hydrolysis of α-d-glucosides and transglucosylation. Bacillus sp. AHU2216 α-glucosidase (BspAG13_31A), belonging to the glycoside hydrolase family 13 subfamily 31, specifically cleaves α-(1→4)-glucosidic linkages and shows high disaccharide specificity. We showed previously that the maltose moiety of maltotriose (G3) and maltotetraose (G4), covering subsites +1 and +2 of BspAG13_31A, adopts a less stable conformation than the global minimum energy conformation. This unstable d-glucosyl conformation likely arises from steric hindrance by Asn258 on β→α loop 5 of the catalytic (β/α)8-barrel. In this study, Asn258 mutants of BspAG13_31A were enzymatically and structurally analyzed. N258G/P mutations significantly enhanced trisaccharide specificity. The N258P mutation also enhanced the activity toward sucrose and produced erlose from sucrose through transglucosylation. N258G showed a higher specificity to transglucosylation with p-nitrophenyl α-d-glucopyranoside and maltose than the wild type. E256Q/N258G and E258Q/N258P structures in complex with G3 revealed that the maltose moiety of G3 bound at subsites +1 and +2 adopted a relaxed conformation, whereas a less stable conformation was taken in E256Q. This structural difference suggests that stabilizing the G3 conformation enhances trisaccharide specificity. The E256Q/N258G-G3 complex formed an additional hydrogen bond between Met229 and the d-glucose residue of G3 in subsite +2, and this interaction may enhance transglucosylation.
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Affiliation(s)
| | - Wataru Saburi
- Research Faculty of Agriculture, Hokkaido Unifversity, Sapporo 060-8589, Japan; (W.A.)
- Correspondence: (W.S.); (H.M.); Tel.: +81-11-806-2508 (W.S.); +81-11-706-2497 (H.M.)
| | - Tomoya Ota
- Research Faculty of Agriculture, Hokkaido Unifversity, Sapporo 060-8589, Japan; (W.A.)
| | - Jian Yu
- Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Koji Kato
- Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Min Yao
- Faculty of Advanced Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Haruhide Mori
- Research Faculty of Agriculture, Hokkaido Unifversity, Sapporo 060-8589, Japan; (W.A.)
- Correspondence: (W.S.); (H.M.); Tel.: +81-11-806-2508 (W.S.); +81-11-706-2497 (H.M.)
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Wu Y, Yu X, Zhou H, Li S, Wu X, Zhao J. Revealing the critical role of Leucine145 of α-glucosidase AglA for enhancing α-arbutin production. MOLECULAR CATALYSIS 2023. [DOI: 10.1016/j.mcat.2023.112943] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
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8
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Abadan S, Saglam MF, Koca MS, Bingul M, Sahin H, Zorlu Y, Sengul IF. Synthesis and Molecular Modeling Studies of Naphthazarin Derivatives as Novel Selective Inhibitors of α-Glucosidase and α-Amylase. J Mol Struct 2023. [DOI: 10.1016/j.molstruc.2023.134954] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
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Riaz NN, Ahmed MM, Kashif M, Sajid M, Ali M, Mahmood K. Biologically potent organotin( iv) complexes of N-acetylated β-amino acids with spectroscopic, X-ray powder diffraction and molecular docking studies †. RSC Adv 2023; 13:10768-10789. [PMID: 37033437 PMCID: PMC10074041 DOI: 10.1039/d2ra06718h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2022] [Accepted: 03/07/2023] [Indexed: 04/08/2023] Open
Abstract
Twelve novel organotin(iv) complexes (1–12) of N-acetylated β-amino acids (L1–L8) were synthesized and characterized by elemental analysis, FTIR, multinuclear (1H, 13C, 119Sn) NMR, EI-MS and powder XRD techniques. The XRD results determined lattice parameters, average particle size, and intrinsic strain and confirmed the crystalline nature of complexes as face centered cubic phases. Molecular docking analysis using a catalytic pocket of the α-glucosidase enzyme indicated that most of the compounds displayed a well-fitted orientation and occupied important amino acids in the enzyme's catalytic pocket. Furthermore, in vitro α-glucosidase inhibitory activity results revealed that L1 and complexes 4, 6 and 10 showed the highest activity with IC50 values of 21.54 ± 0.45, 37.96 ± 0.81 and 35.20 ± 1.02, respectively, compared to standard acarbose with an IC50 value of 42.51 ± 0.21. In addition, in vivo antidiabetic activity of selected compounds using alloxan induced diabetic rabbits showed that L4 and complexes 4, 6, 10, 12 showed significant activities like standard metformin. Anti-bacterial activity against the selected Gram-positive and Gram-negative bacterial strains has the following order Escherichia coli > Pseudomonas aeruginosa > Staphylococcus aureus > Bacillus subtilis. Similarly, antioxidant activity by the DPPH scavenging method was also studied with following results: triorganotin > diorganotin > ligands. Novel organotin(iv) complexes of N-acetylated β-amino acids were synthesized and characterized by different techniques. The molecular docking, in vitro α-glucosidase inhibitory, and in vivo antidiabetic activity studies were carried out.![]()
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Affiliation(s)
- Nagina Naveed Riaz
- Institute of Chemical Sciences, Bahauddin Zakariya UniversityMultanPakistan
- Department of Chemistry, Division of Science & Technology, University of EducationLahorePakistan
| | | | | | - Muhammad Sajid
- Institute of Chemical Sciences, Bahauddin Zakariya UniversityMultanPakistan
| | - Muhammad Ali
- School of Materials Science and Engineering, University of Science and Technology of China96 Jinzhai Road, Baohe DistrictHefei230026PR China
| | - Khalid Mahmood
- Institute of Chemical Sciences, Bahauddin Zakariya UniversityMultanPakistan
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Aly SH, Eldahshan OA, Al-Rashood ST, Binjubair FA, El Hassab MA, Eldehna WM, Dall’Acqua S, Zengin G. Chemical Constituents, Antioxidant, and Enzyme Inhibitory Activities Supported by In-Silico Study of n-Hexane Extract and Essential Oil of Guava Leaves. Molecules 2022; 27:molecules27248979. [PMID: 36558111 PMCID: PMC9781903 DOI: 10.3390/molecules27248979] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Revised: 12/05/2022] [Accepted: 12/06/2022] [Indexed: 12/23/2022] Open
Abstract
Psidium guajava (Guava tree) is one of the most widely known species in the family Myrtaceae. The Guava tree has been reported for its potential antioxidant, anti-inflammatory, antimicrobial, and cytotoxic activities. In the current study, the chemical compositions of the n-hexane extract and the essential oil of P. guajava were investigated using the GC/MS analysis, along with an evaluation of their antioxidant potential, and an investigation into the enzyme inhibition of acetylcholinesterase (AChE), butyrylcholinesterase (BchE), tyrosinase, α-amylase, and α-glucosidase. Moreover, molecular docking of the major identified active sites of the target enzymes were investigated. The chemical characterization of the n-hexane extract and essential oil revealed that squalene (9.76%), α-tocopherol (8.53%), and γ-sitosterol (3.90%) are the major compounds in the n-hexane extract. In contrast, the major constituents of the essential oil are D-limonene (36.68%) and viridiflorol (9.68%). The n-hexane extract showed more antioxidant potential in the cupric reducing antioxidant capacity (CUPRAC), the ferric reducing power (FRAP), and the metal chelating ability (MCA) assays, equivalent to 70.80 ± 1.46 mg TE/g, 26.01 ± 0.97 mg TE/g, and 24.83 ± 0.35 mg EDTAE/g, respectively. In the phosphomolybdenum (PM) assay, the essential oil showed more antioxidant activity equivalent to 2.58 ± 0.14 mmol TE/g. The essential oil demonstrated a potent BChE and tyrosinase inhibitory ability at 6.85 ± 0.03 mg GALAE/g and 61.70 ± 3.21 mg KAE/g, respectively. The α-amylase, and α-glucosidase inhibitory activity of the n-hexane extract and the essential oil varied from 0.52 to 1.49 mmol ACAE/g. Additionally, the molecular docking study revealed that the major compounds achieved acceptable binding scores upon docking with the tested enzymes. Consequently, the P. guajava n-hexane extract and oil can be used as a promising candidate for the development of novel treatment strategies for oxidative stress, neurodegeneration, and diabetes mellitus diseases.
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Affiliation(s)
- Shaza H. Aly
- Department of Pharmacognosy, Faculty of Pharmacy, Badr University in Cairo (BUC), Cairo 11829, Egypt
| | - Omayma A. Eldahshan
- Pharmacognosy Department, Faculty of Pharmacy, Ain Shams University, Cairo 11566, Egypt
- Center for Drug Discovery Research and Development, Ain Shams University, Cairo 11566, Egypt
- Correspondence: (O.A.E.); (G.Z.)
| | - Sara T. Al-Rashood
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Faizah A. Binjubair
- Department of Pharmaceutical Chemistry, College of Pharmacy, King Saud University, P.O. Box 2457, Riyadh 11451, Saudi Arabia
| | - Mahmoud A. El Hassab
- Department of Medicinal Chemistry, Faculty of Pharmacy, King Salman International University (KSIU), South Sinai 46612, Egypt
| | - Wagdy M. Eldehna
- Department of Pharmaceutical Chemistry, Faculty of Pharmacy, Kafrelsheikh University, Kafrelsheikh 33516, Egypt
- School of Biotechnology, Badr University in Cairo, Badr City, Cairo 11829, Egypt
| | - Stefano Dall’Acqua
- Department of Pharmaceutical and Pharmacological Sciences, University of Padova, 35131 Padova, Italy
| | - Gokhan Zengin
- Department of Biology, Science Faculty, Selcuk University, Konya 42130, Turkey
- Correspondence: (O.A.E.); (G.Z.)
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Mohamed AI, Salau VF, Erukainure OL, Islam MS. Hibiscus sabdariffa L. polyphenolic-rich extract promotes muscle glucose uptake and inhibits intestinal glucose absorption with concomitant amelioration of Fe 2+ -induced hepatic oxidative injury. J Food Biochem 2022; 46:e14399. [PMID: 36259155 DOI: 10.1111/jfbc.14399] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2022] [Revised: 08/15/2022] [Accepted: 08/18/2022] [Indexed: 01/13/2023]
Abstract
In this current study, the antidiabetic effectiveness of Hibiscus sabdariffa and its protective function against Fe2+ -induced oxidative hepatic injury were elucidated using in vitro, in silico, and ex vivo studies. The oxidative damage was induced in hepatic tissue by incubation with 0.1 mMolar ferrous sulfate (FeSO4) and then treated with different concentrations of crude extracts (ethyl acetate, ethanol, and aqueous) of H. sabdariffa flowers for 30 min at 37°C. When compared to ethyl acetate and aqueous extracts, the ethanolic extract displayed the most potent scavenging activity in ferric-reducing antioxidant power (FRAP), 1,1-diphenyl-2-picrylhydrazyl (DPPH), and nitric oxide (NO) assays, with IC50 values of 2.8 μl/ml, 3.3 μl/ml, and 9.2 μl/ml, respectively. The extracts significantly suppressed α-glucosidase and α-amylase activities (p < .05), with the ethanolic extract demonstrating the highest activity. H. sabdariffa significantly (p < .05) raised reduced glutathione (GSH) levels while simultaneously decreasing malondihaldehyde (MDA) and NO levels and increasing superoxide dismutase (SOD) and catalase activity in Fe2+ induced oxidative hepatic injury. The extract of the plant inhibited intestinal glucose absorption and increased muscular glucose uptake. The extract revealed the presence of several phenolic compounds when submitted to gas chromatography-mass Spectroscopy (GC-MS) screening, which was docked with α-glucosidase and α- amylase. The molecular docking displayed the compound 4-(3,5-Di-tert-butyl-4-hydroxyphenyl)butyl acrylate strongly interacted with α-glucosidase and α-amylase and had the lowest free binding energy compared to other compounds and acarbose. These results suggest that H. sabdariffa has promising antioxidant and antidiabetic activity. PRACTICAL APPLICATIONS: In recent years, there has been increased concern about the side effects of synthetic anti-diabetic drugs, as well as their expensive cost, especially in impoverished nations. This has instigated a radical shift towards the use of traditional plants, which are rich in phytochemicals many years ago. Among these plants, H. sabdariffa has been used to treat diabetes in traditional medicine. In this present study, H. sabdariffa extracts demonstrated the ability to inhibit carbohydrate digesting enzymes, facilitate muscle glucose uptake and attenuate oxidative stress in oxidative hepatic injury. Hence, demonstrating H. sabdariffa's potential to protect against oxidative damage and the complications associated with diabetes. Consumption of Hibiscus tea or juice may be a potential source for developing an anti-diabetic drug.
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Affiliation(s)
- Almahi I Mohamed
- Department of Biochemistry, School of Life Sciences, University of Kwazulu-Natal, Westville Campus, Durban, South Africa
| | - Veronica F Salau
- Department of Biochemistry, School of Life Sciences, University of Kwazulu-Natal, Westville Campus, Durban, South Africa.,Department of Pharmacology, University of the Free State, Bloemfontein, South Africa
| | - Ochuko L Erukainure
- Department of Pharmacology, University of the Free State, Bloemfontein, South Africa
| | - Md Shahidul Islam
- Department of Biochemistry, School of Life Sciences, University of Kwazulu-Natal, Westville Campus, Durban, South Africa
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Mohammadi‐Khanaposhtani M, Noori M, Valizadeh Y, Dastyafteh N, Ghomi MK, Mojtabavi S, Faramarzi MA, Hosseini S, Biglar M, Larijani B, Rastegar H, Hamedifar H, Mirzazadeh R, Mahdavi M. Synthesis, α‐glucosidase Inhibition,
in silico
Pharmacokinetic, and Docking Studies Of Thieno[2,3‐b]Quinoline‐Acetamide Derivatives as New Anti‐Diabetic Agents. ChemistrySelect 2022. [DOI: 10.1002/slct.202104482] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Maryam Mohammadi‐Khanaposhtani
- Cellular and Molecular Biology Research Center Health Research Institute Babol University of Medical Sciences Babol Iran
| | - Milad Noori
- Endocrinology and Metabolism Research Center Endocrinology and Metabolism Clinical Sciences Institute Tehran University of Medical Sciences Tehran Iran
| | - Yousef Valizadeh
- Endocrinology and Metabolism Research Center Endocrinology and Metabolism Clinical Sciences Institute Tehran University of Medical Sciences Tehran Iran
| | - Navid Dastyafteh
- Endocrinology and Metabolism Research Center Endocrinology and Metabolism Clinical Sciences Institute Tehran University of Medical Sciences Tehran Iran
| | - Minoo Khalili Ghomi
- Endocrinology and Metabolism Research Center Endocrinology and Metabolism Clinical Sciences Institute Tehran University of Medical Sciences Tehran Iran
| | - Somayeh Mojtabavi
- Department of Pharmaceutical Biotechnology Faculty of Pharmacy Tehran University of Medical Sciences Tehran Iran
| | - Mohammad Ali Faramarzi
- Department of Pharmaceutical Biotechnology Faculty of Pharmacy Tehran University of Medical Sciences Tehran Iran
| | | | - Mahmood Biglar
- Endocrinology and Metabolism Research Center Endocrinology and Metabolism Clinical Sciences Institute Tehran University of Medical Sciences Tehran Iran
| | - Bagher Larijani
- Endocrinology and Metabolism Research Center Endocrinology and Metabolism Clinical Sciences Institute Tehran University of Medical Sciences Tehran Iran
| | - Hossein Rastegar
- Cosmetic products research center, Iranian food and drug administration, MOHE Tehran Iran
| | - Haleh Hamedifar
- CinnaGen Medical Biotechnology Research Center Alborz University of Medical Sciences Karaj Iran
| | | | - Mohammad Mahdavi
- Endocrinology and Metabolism Research Center Endocrinology and Metabolism Clinical Sciences Institute Tehran University of Medical Sciences Tehran Iran
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13
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Boukharsa Y, Karrouchi K, Anouar EH, Albalwi H, Jarbi I, Ramli Y, Faouzi MEA, Ansar M. Synthesis, α-Glucosidase and β-Galactosidase Inhibitory Potentials and Molecular Docking of Some Novel Benzofuran-Pyridazine Derivatives. Polycycl Aromat Compd 2022. [DOI: 10.1080/10406638.2022.2149561] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Youness Boukharsa
- Laboratory of Medicinal Chemistry, Faculty of Medicine and Pharmacy, Mohammed V University of Rabat, Rabat, Morocco
| | - Khalid Karrouchi
- Laboratory of Analytical Chemistry and Bromatology, Team of Formulation and Quality Control of Health Products, Faculty of Medicine and Pharmacy, Mohammed V University, Rabat, Morocco
| | - El Hassane Anouar
- Department of Chemistry, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | - Hanan Albalwi
- Department of Chemistry, College of Science and Humanities in Al-Kharj, Prince Sattam Bin Abdulaziz University, Al-Kharj, Saudi Arabia
| | - Ibtissam Jarbi
- Laboratory of Pharmacology and Toxicology, Biopharmaceutical and Toxicological Analysis Research Team, Faculty of Medicine and Pharmacy, Mohammed V University of Rabat, Rabat, Morocco
| | - Youssef Ramli
- Laboratory of Medicinal Chemistry, Faculty of Medicine and Pharmacy, Mohammed V University of Rabat, Rabat, Morocco
| | - My El Abbes Faouzi
- Laboratory of Pharmacology and Toxicology, Biopharmaceutical and Toxicological Analysis Research Team, Faculty of Medicine and Pharmacy, Mohammed V University of Rabat, Rabat, Morocco
| | - M’hammed Ansar
- Laboratory of Medicinal Chemistry, Faculty of Medicine and Pharmacy, Mohammed V University of Rabat, Rabat, Morocco
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14
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Efficient one-pot synthesis of arylated pyrazole-fused pyran analogs: as leads to treating diabetes and Alzheimer's disease. Future Med Chem 2022; 14:1507-1526. [PMID: 36268762 DOI: 10.4155/fmc-2022-0103] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background: To discover novel lead molecules against diabetes, Alzheimer's disease and oxidative stress, a library of arylated pyrazole-fused pyran derivatives, 1-20, were synthesized in a one-pot reaction. Materials & methods:1H-NMR spectroscopic and electron ionization mass spectrometry techniques were used to characterize the synthetic hybrid molecules 1-20. Analogs were screened against four indispensable therapeutic targets, including α-amylase, α-glucosidase, acetylcholinesterase and butyrylcholinesterase enzymes. Results: Except for derivatives 17 and 18, all other compounds exhibited varying degrees of inhibitory activities against target enzymes. The kinetic studies revealed that the synthetic molecules followed a competitive-type mode of inhibition for α-amylase and acetylcholinesterase enzymes, as well as a non-competitive mode of inhibition for α-glucosidase and butyrylcholinesterase enzymes. In addition, molecular docking studies identified crucial binding interactions of ligands with the enzyme's active site. Conclusion: These molecules may serve as a potential drug candidate to cure diabetes, Alzheimer's disease and oxidative stress in the future.
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15
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Ponneganti S, Suryanarayana Murty U, Bagul C, Borkar RM, Radhakrishnanand P. Phyto-metabolomics of phlogacanthus thyrsiformis by using LC-ESI-QTOF-MS/MS and GC/QTOF-MS: Evaluation of antioxidant and enzyme inhibition potential of extracts. Food Res Int 2022; 161:111874. [DOI: 10.1016/j.foodres.2022.111874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 08/04/2022] [Accepted: 08/23/2022] [Indexed: 11/26/2022]
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16
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Noori M, Rastak M, Halimi M, Ghomi MK, Mollazadeh M, Mohammadi-Khanaposhtani M, Sayahi MH, Rezaei Z, Mojtabavi S, Ali Faramarzi M, Larijani B, Biglar M, Amanlou M, Mahdavi M. Design, synthesis, in vitro, and in silico enzymatic evaluations of thieno[2,3-b]quinoline-hydrazones as novel inhibitors for α-glucosidase. Bioorg Chem 2022; 127:105996. [PMID: 35878449 DOI: 10.1016/j.bioorg.2022.105996] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Revised: 06/15/2022] [Accepted: 06/27/2022] [Indexed: 11/25/2022]
Abstract
In the development of novel anti-α-glucosidase agents, we synthesized novel thieno[2,3-b]quinoline-hydrazones 9a-n by facile and efficient conventional chemical reactions. These compounds were characterized by IR, 1H NMR, 13C NMR, and elemental analysis. Inhibitory activities of the title compounds were evaluated against yeast α-glucosidase. In particular, compounds 9c, 9d, and 9h exhibited high anti-α-glucosidase activity. Representatively, compound 9c with IC50 = 1.3 µM, was 576-times more potent than positive control acarbose. Molecular docking study of the most active compounds showed that these compounds formed important binding interactions at α-glucosidase active site. Molecular dynamics study of compound 9c was also performed and the obtained results were compared with acarbose. Compounds 9c, 9d, and 9h were also evaluated for in silico druglikeness properties and ADMET prediction. These studies showed that the title most potent compounds could be exploited as drug candidates.
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Affiliation(s)
- Milad Noori
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mryam Rastak
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Halimi
- Department of Biology, Babol Branch, Islamic Azad University, Babol, Iran
| | - Minoo Khalili Ghomi
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mrjan Mollazadeh
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Maryam Mohammadi-Khanaposhtani
- Cellular and Molecular Biology Research Center, Health Research Institute, Babol University of Medical Sciences, Babol, Iran
| | - Mohammad Hosein Sayahi
- Department of Chemistry, Payame Noor University (PNU), P.O. Box 19395-3697, Tehran, Iran
| | - Zahra Rezaei
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Somayeh Mojtabavi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Ali Faramarzi
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran
| | - Bagher Larijani
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahmood Biglar
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran
| | - Massoud Amanlou
- Department of Medicinal Chemistry, Faculty of Pharmacy, Tehran University of Medical Sciences, Tehran, Iran.
| | - Mohammad Mahdavi
- Endocrinology and Metabolism Research Center, Endocrinology and Metabolism Clinical Sciences Institute, Tehran University of Medical Sciences, Tehran, Iran.
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17
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Zhang K, Chen XL, Zhao X, Ni JY, Wang HL, Han M, Zhang YM. Antidiabetic potential of Catechu via assays for α-glucosidase, α-amylase, and glucose uptake in adipocytes. JOURNAL OF ETHNOPHARMACOLOGY 2022; 291:115118. [PMID: 35202712 DOI: 10.1016/j.jep.2022.115118] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2021] [Revised: 01/28/2022] [Accepted: 02/14/2022] [Indexed: 06/14/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Catechu is the dry water extract of barked branches or stems from Senegalia catechu(L. F.)P. J. H. Hurter & Mabb, which is used as a hypoglycemic regulator in recent researches. Potential anti-hyperglycemic components and the putative mechanisms were evaluated in this investigation. AIM OF THE STUDY Evaluated the hypoglycemic activity of Catechu via α-glucosidase, α-amylase inhibition assays, and glucose uptake in 3T3-L1 adipocytes. MATERIALS AND METHODS The effects of Catechu on α-glucosidase, α-amylase inhibition assays and glucose uptake experiment were tested after the ethanol extract of Catechu (EE) was sequentially partitioned with petroleum ether (PEE), ethyl acetate (EAE), and n-butanol fractions (NBE). Next, HPLC-MS and traditional Chinese medicine (TCM) database were used to detect and analyze the primary active ingredients presented in hypoglycemic fraction. In addition, in silico molecular docking study was used to evaluate the candidates' inhibitory activity against α-glucosidase and α-amylase. RESULTS The results of α-glucosidase and α-amylase inhibition assays indicated that all fractions, with the exception of PEE, presented significant inhibitory effects on α-glucosidase and α-amylase. The inhibitory effect of NBE on α-glucosidase was similar to the positive control (NBE IC50 = 0.3353 ± 0.1215 μg/mL; Acarbose IC50 = 0.1123 ± 0.0023 μg/mL). Furthermore, the inhibitory kinetics of α-glucosidase revealed that all fractions except for PEE belong to uncompetitive type. In silico molecular docking analysis showed that the main compositions of NBE ((-)-epicatechin, cyanidin, and delphinidin) possessed superior binding capacities with α-glucosidase (3WY1 AutoDock score: 4.82 kcal/mol; -5.59 kcal/mol; -5.63 kcal/mol) and α-amylase (4GQR AutoDock score: 4.80 kcal/mol; -5.89 kcal/mol; -4.26 kcal/mol), respectively. The results of glucose uptake experiment indicated that EE, PEE, EAE, and NBE without significant promotion effect on glucose uptake rate of 3T3-L1 adipocytes (P > 0.05). CONCLUSION This study revealed that the hypoglycemic effect of Catechu might be related to the inhibitory effects of phenols on digestive enzymes (α-glucosidase and α-amylase), and the possible active phenols were (-)-epicatechin, cyanidin, delphinidin and their derivatives, which provided scientific evidences for Catechu's traditional use to treat T2DM.
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Affiliation(s)
- Kun Zhang
- Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China.
| | - Xue-Lin Chen
- Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Xia Zhao
- Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China.
| | - Ji-Yan Ni
- Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Han-Lei Wang
- Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Mei Han
- Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Yu-Mei Zhang
- Key Laboratory of Tropical Plant Resource and Sustainable Use Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming, 650223, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
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18
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Hypoglycemic and Antioxidant Properties of Extracts and Fractions from Polygoni Avicularis Herba. Molecules 2022; 27:molecules27113381. [PMID: 35684319 PMCID: PMC9182118 DOI: 10.3390/molecules27113381] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 05/13/2022] [Accepted: 05/20/2022] [Indexed: 12/16/2022] Open
Abstract
Our research focused on the hypoglycemic capability and the possible mechanisms of extract and fractions from Polygoni Avicularis Herba (PAH) based on α-glucosidase, α-amylase inhibition assays, glucose uptake experiment, HPLC-MS analysis, and molecular docking experiment. In addition, DPPH, ABTS, and FRAP assays were used for determining the antioxidant capability. The results of total flavonoids and phenolics contents showed that ethyl acetate fraction (EAF) possessed the highest flavonoids and phenolics with values of 159.7 ± 2.5 mg rutin equivalents/g and 107.6 ± 2.0 mg galic acid equivalents/g, respectively. The results of in vitro hypoglycemic activity showed that all samples had effective α-glucosidase inhibition capacities, and EAF possessed the best inhibitory effect with IC50 value of 1.58 ± 0.24 μg/mL. In addition, n-butanol fraction (NBF) significantly promoted the glucose uptake rate of 3T3-L1 adipocytes. HPLC-MS analysis and molecular docking results proved the interactions between candidates and α-glucosidase. The results of antioxidation capacities showed that EAF possessed the best antioxidation abilities with DPPH, ABTS, and FRAP. In summary, the hypoglycemic activity of PAH might be related to the inhibition of α-glucosidase (EAF > PEF > NBF) and the promotion of glucose uptake in 3T3-L1 adipocytes (NBF). Simultaneously, the antioxidation capacity of PAH might be related to the abundant contents of flavonoids and other phenolics (EAF > PEF > NBF).
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19
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Improving the Transglycosylation Activity of α-Glucosidase from Xanthomonas campestris Through Semi-rational Design for the Synthesis of Ethyl Vanillin-α-Glucoside. Appl Biochem Biotechnol 2022; 194:3082-3096. [DOI: 10.1007/s12010-022-03908-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 03/14/2022] [Indexed: 11/26/2022]
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20
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Zhai X, Wu K, Ji R, Zhao Y, Lu J, Yu Z, Xu X, Huang J. Structure and Function Insight of the α-Glucosidase QsGH13 From Qipengyuania seohaensis sp. SW-135. Front Microbiol 2022; 13:849585. [PMID: 35308395 PMCID: PMC8928221 DOI: 10.3389/fmicb.2022.849585] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 01/21/2022] [Indexed: 11/16/2022] Open
Abstract
The α-glucosidases play indispensable roles in the metabolic mechanism of organism, prevention, and treatment of the disease, and sugar hydrolysis, and are widely used in chemical synthesis, clinical diagnosis, and other fields. However, improving their catalytic efficiency and production to meet commercial demand remains a huge challenge. Here we detected a novel GH13 family α-glucosidase, QsGH13, from the deep-sea bacterium Qipengyuania seohaensis sp. SW-135. QsGH13 is highly substrate specific and only hydrolyzes sugars containing alpha-1,4 glucoside bonds. For example, its enzymatic activity for p-nitrophenyl-α-D-glucopyranoside was 25.41 U/mg, and the Km value was 0.2952 ± 0.0322 mM. The biochemical results showed that the optimum temperature of QsGH13 is 45°C, the optimum pH is 10.0, and it has excellent biological characteristics such as alkali resistance and salt resistance. The crystal structure of QsGH13 was resolved with a resolution of 2.2 Å, where QsGH13 is composed of a typical TIM barrel catalytic domain A, a loop-rich domain B, and a conserved domain C. QsGH13 crystal belonged to the monoclinic space group P212121, with unit-cell parameters a = 58.816 Å, b = 129.920 Å, c = 161.307 Å, α = γ = β = 90°, which contains two monomers per asymmetric unit. The β → α loop 4 of QsGH13 was located above catalytic pocket. Typical catalytic triad residues Glu202, Asp266, and Glu329 were found in QsGH13. The biochemical properties and structural analysis of QsGH13 have greatly improved our understanding of the catalytic mechanism of GH13 family. This study provides new ideas to broaden the application of α-glucosidase in alcohol fermentation, glycolysis, and other industries.
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Affiliation(s)
- Xingyu Zhai
- Department of Parasitology, School of Basic Medical Science, Central South University, Changsha, China.,Department of Microbiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Kaijuan Wu
- Department of Parasitology, School of Basic Medical Science, Central South University, Changsha, China
| | - Rui Ji
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, China
| | - Yiming Zhao
- Department of Microbiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Jianhong Lu
- Department of Microbiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Zheng Yu
- Department of Microbiology, Xiangya School of Medicine, Central South University, Changsha, China
| | - Xuewei Xu
- Key Laboratory of Marine Ecosystem Dynamics, Second Institute of Oceanography, Ministry of Natural Resources, Hangzhou, China
| | - Jing Huang
- Department of Parasitology, School of Basic Medical Science, Central South University, Changsha, China
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Kurbanova M, Maharramov A, Safarova A, Ahmad S, El Bakri Y. Molecular docking study and molecular dynamics simulation of ethyl 3,5‐diphenyl‐1
H
‐pyrrole‐2‐carboxylate and (Z)‐ethyl‐2‐(3‐oxo‐1,3‐diphenylprop‐1‐enylamino)acetate. J Biochem Mol Toxicol 2022; 36:e23013. [DOI: 10.1002/jbt.23013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 12/24/2021] [Accepted: 01/28/2022] [Indexed: 11/09/2022]
Affiliation(s)
| | - Abel Maharramov
- Organic Chemistry Department Baku State University Baku Azerbaijan
| | - Aytan Safarova
- Organic Chemistry Department Baku State University Baku Azerbaijan
| | - Sajjad Ahmad
- Department of Health and Biological Sciences Abasyn University Peshawar Pakistan
| | - Youness El Bakri
- Department of Theoretical and Applied Chemistry South Ural State University Chelyabinsk Russian Federation
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22
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Structural analysis of halogenated bicyclo[4.2.0] inositols, biological activities and molecular docking studies. J Mol Struct 2022. [DOI: 10.1016/j.molstruc.2021.131357] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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23
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Multi-Mechanistic In Vitro Evaluation of Antihyperglycemic, Antioxidant and Antiglycation Activities of Three Phenolic-Rich Indian Red Rice Genotypes and In Silico Evaluation of Their Phenolic Metabolites. Foods 2021; 10:foods10112818. [PMID: 34829098 PMCID: PMC8617766 DOI: 10.3390/foods10112818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2021] [Revised: 10/21/2021] [Accepted: 10/21/2021] [Indexed: 11/26/2022] Open
Abstract
The study evaluated the antidiabetic potential of three traditional Indian red rice genotypes/RR (Kattuyanam/KA, Chennangi/CH & Karungkuruvai/KU) using a combination of in vitro, metabolomics (Quadrupole-Time of Flight-Liquid chromatography-Mass spectrometry/Q-TOF-LC-MS/MS), and in silico techniques. In terms of antihyperglycemic potential, KA exhibited the highest inhibitory activity against α-amylase; CH against α-glucosidase; and KU against DPPIV and PTP1B enzymes. KA exhibited the highest antioxidant activity (DPPH, FRAP, and ABTS) and greater inhibition of protein glycation compared to other RR indicating its potential to mitigate diabetic complications. The metabolomic analysis confirmed the presence of 99 phenolics in the sample extracts (KU-71, KA-70, CH-68). Molecular docking studies revealed seven metabolites to be good inhibitors of the four target enzymes and activators of insulin receptor substrate/IRS. The antihyperglycemic and oxidation-glycation reduction composite index revealed KA to have the highest overall antidiabetic potential. Hence, the RR could be utilized in functional foods with a multi-barrelled strategy for diabetes prevention/management.
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Kaya Y, Erçağ A, Serdaroğlu G, Kaya S, Grillo IB, Rocha GB. Synthesis, spectroscopic characterization, DFT calculations, and molecular docking studies of new unsymmetric bishydrazone derivatives. J Mol Struct 2021. [DOI: 10.1016/j.molstruc.2021.131224] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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25
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Fuchs T, Melcher F, Rerop ZS, Lorenzen J, Shaigani P, Awad D, Haack M, Prem SA, Masri M, Mehlmer N, Brueck TB. Identifying carbohydrate-active enzymes of Cutaneotrichosporon oleaginosus using systems biology. Microb Cell Fact 2021; 20:205. [PMID: 34711240 PMCID: PMC8555327 DOI: 10.1186/s12934-021-01692-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Accepted: 10/05/2021] [Indexed: 11/30/2022] Open
Abstract
Background The oleaginous yeast Cutaneotrichosporon oleaginosus represents one of the most promising microbial platforms for resource-efficient and scalable lipid production, with the capacity to accept a wide range of carbohydrates encapsulated in complex biomass waste or lignocellulosic hydrolysates. Currently, data related to molecular aspects of the metabolic utilisation of oligomeric carbohydrates are sparse. In addition, comprehensive proteomic information for C. oleaginosus focusing on carbohydrate metabolism is not available. Results In this study, we conducted a systematic analysis of carbohydrate intake and utilisation by C. oleaginosus and investigated the influence of different di- and trisaccharide as carbon sources. Changes in the cellular growth and morphology could be observed, depending on the selected carbon source. The greatest changes in morphology were observed in media containing trehalose. A comprehensive proteomic analysis of secreted, cell wall-associated, and cytoplasmatic proteins was performed, which highlighted differences in the composition and quantity of secreted proteins, when grown on different disaccharides. Based on the proteomic data, we performed a relative quantitative analysis of the identified proteins (using glucose as the reference carbon source) and observed carbohydrate-specific protein distributions. When using cellobiose or lactose as the carbon source, we detected three- and five-fold higher diversity in terms of the respective hydrolases released. Furthermore, the analysis of the secreted enzymes enabled identification of the motif with the consensus sequence LALL[LA]L[LA][LA]AAAAAAA as a potential signal peptide. Conclusions Relative quantification of spectral intensities from crude proteomic datasets enabled the identification of new enzymes and provided new insights into protein secretion, as well as the molecular mechanisms of carbo-hydrolases involved in the cleavage of the selected carbon oligomers. These insights can help unlock new substrate sources for C. oleaginosus, such as low-cost by-products containing difficult to utilize carbohydrates. In addition, information regarding the carbo-hydrolytic potential of C. oleaginosus facilitates a more precise engineering approach when using targeted genetic approaches. This information could be used to find new and more cost-effective carbon sources for microbial lipid production by the oleaginous yeast C. oleaginosus. Supplementary Information The online version contains supplementary material available at 10.1186/s12934-021-01692-2.
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Affiliation(s)
- Tobias Fuchs
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Felix Melcher
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Zora Selina Rerop
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Jan Lorenzen
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Pariya Shaigani
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Dania Awad
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Martina Haack
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Sophia Alice Prem
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Mahmoud Masri
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Norbert Mehlmer
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany.
| | - Thomas B Brueck
- Werner Siemens-Chair of Synthetic Biotechnology (WSSB), Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany.
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Fort J, Nicolàs-Aragó A, Palacín M. The Ectodomains of rBAT and 4F2hc Are Fake or Orphan α-Glucosidases. Molecules 2021; 26:6231. [PMID: 34684812 PMCID: PMC8537225 DOI: 10.3390/molecules26206231] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/11/2021] [Accepted: 10/12/2021] [Indexed: 11/22/2022] Open
Abstract
It is known that 4F2hc and rBAT are the heavy subunits of the heteromeric amino acid transporters (HATs). These heavy subunits are N-glycosylated proteins, with an N-terminal domain, one transmembrane domain and a bulky extracellular domain (ectodomain) that belongs to the α-amylase family. The heavy subunits are covalently linked to a light subunit from the SLC7 family, which is responsible for the amino acid transport activity, forming a heterodimer. The functions of 4F2hc and rBAT are related mainly to the stability and trafficking of the HATs in the plasma membrane of vertebrates, where they exert the transport activity. Moreover, 4F2hc is a modulator of integrin signaling, has a role in cell fusion and it is overexpressed in some types of cancers. On the other hand, some mutations in rBAT are found to cause the malfunctioning of the b0,+ transport system, leading to cystinuria. The ectodomains of 4F2hc and rBAT share both sequence and structure homology with α-amylase family members. Very recently, cryo-EM has revealed the structure of several HATs, including the ectodomains of rBAT and 4F2hc. Here, we analyze available data on the ectodomains of rBAT and 4Fhc and their relationship with the α-amylase family. The physiological relevance of this relationship remains largely unknown.
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Affiliation(s)
- Joana Fort
- Laboratory of Amino Acid Transporters and Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain; (A.N.-A.); (M.P.)
- CIBERER (Centro Español en Red de Biomedicina de Enfermedades Raras), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, 08028 Barcelona, Spain
| | - Adrià Nicolàs-Aragó
- Laboratory of Amino Acid Transporters and Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain; (A.N.-A.); (M.P.)
| | - Manuel Palacín
- Laboratory of Amino Acid Transporters and Disease, Institute for Research in Biomedicine (IRB Barcelona), The Barcelona Institute of Science and Technology (BIST), Baldiri Reixac 10, 08028 Barcelona, Spain; (A.N.-A.); (M.P.)
- CIBERER (Centro Español en Red de Biomedicina de Enfermedades Raras), 08028 Barcelona, Spain
- Department of Biochemistry and Molecular Biomedicine, Universitat de Barcelona, 08028 Barcelona, Spain
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Structural Insight into a Yeast Maltase-The BaAG2 from Blastobotrys adeninivorans with Transglycosylating Activity. J Fungi (Basel) 2021; 7:jof7100816. [PMID: 34682239 PMCID: PMC8539097 DOI: 10.3390/jof7100816] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 09/23/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022] Open
Abstract
An early-diverged yeast, Blastobotrys (Arxula) adeninivorans (Ba), has biotechnological potential due to nutritional versatility, temperature tolerance, and production of technologically applicable enzymes. We have biochemically characterized from the Ba type strain (CBS 8244) the GH13-family maltase BaAG2 with efficient transglycosylation activity on maltose. In the current study, transglycosylation of sucrose was studied in detail. The chemical entities of sucrose-derived oligosaccharides were determined using nuclear magnetic resonance. Several potentially prebiotic oligosaccharides with α-1,1, α-1,3, α-1,4, and α-1,6 linkages were disclosed among the products. Trisaccharides isomelezitose, erlose, and theanderose, and disaccharides maltulose and trehalulose were dominant transglycosylation products. To date no structure for yeast maltase has been determined. Structures of the BaAG2 with acarbose and glucose in the active center were solved at 2.12 and 2.13 Å resolution, respectively. BaAG2 exhibited a catalytic domain with a (β/α)8-barrel fold and Asp216, Glu274, and Asp348 as the catalytic triad. The fairly wide active site cleft contained water channels mediating substrate hydrolysis. Next to the substrate-binding pocket an enlarged space for potential binding of transglycosylation acceptors was identified. The involvement of a Glu (Glu309) at subsite +2 and an Arg (Arg233) at subsite +3 in substrate binding was shown for the first time for α-glucosidases.
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Characterization of an α-Glucosidase Enzyme Conserved in Gardnerella spp. Isolated from the Human Vaginal Microbiome. J Bacteriol 2021; 203:e0021321. [PMID: 34124938 DOI: 10.1128/jb.00213-21] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Gardnerella spp. in the vaginal microbiome are associated with bacterial vaginosis, in which a lactobacillus-dominated community is replaced with mixed bacteria, including Gardnerella species. Co-occurrence of multiple Gardnerella species in the vaginal environment is common, but different species are dominant in different women. Competition for nutrients, including glycogen, could play an important role in determining the microbial community structure. Digestion of glycogen into products that can be taken up and further processed by bacteria requires the combined activities of several enzymes collectively known as amylases, which belong to glycoside hydrolase family 13 (GH13) within the CAZy classification system. GH13 is a large and diverse family of proteins, making prediction of their activities challenging. SACCHARIS annotation of the GH13 family in Gardnerella resulted in identification of protein domains belonging to eight subfamilies. Phylogenetic analysis of predicted amylase sequences from 26 genomes demonstrated that a putative α-glucosidase-encoding sequence, CG400_06090, was conserved in all Gardnerella spp. The predicted α-glucosidase enzyme was expressed, purified, and functionally characterized. The enzyme was active on a variety of maltooligosaccharides with maximum activity at pH 7. Km, kcat, and kcat/Km values for the substrate 4-nitrophenyl α-d-glucopyranoside were 8.3 μM, 0.96 min-1, and 0.11 μM-1 min-1, respectively. Glucose was released from maltose, maltotriose, maltotetraose, and maltopentaose, but no products were detected when the enzyme was incubated with glycogen. Our findings show that Gardnerella spp. produce an α-glucosidase enzyme that may contribute to the multistep process of glycogen metabolism by releasing glucose from maltooligosaccharides. IMPORTANCE Increased abundance of Gardnerella spp. is a diagnostic characteristic of bacterial vaginosis, an imbalance in the human vaginal microbiome associated with troubling symptoms, and negative reproductive health outcomes, including increased transmission of sexually transmitted infections and preterm birth. Competition for nutrients is likely an important factor in causing dramatic shifts in the vaginal microbial community but little is known about the contribution of bacterial enzymes to the metabolism of glycogen, a major carbon source available to vaginal bacteria. The significance of our research is characterizing the activity of an enzyme conserved in Gardnerella species that likely contributes to the ability of these bacteria to utilize glycogen.
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Wangpaiboon K, Laohawuttichai P, Kim SY, Mori T, Nakapong S, Pichyangkura R, Pongsawasdi P, Hakoshima T, Krusong K. A GH13 α-glucosidase from Weissella cibaria uncommonly acts on short-chain maltooligosaccharides. ACTA CRYSTALLOGRAPHICA SECTION D-STRUCTURAL BIOLOGY 2021; 77:1064-1076. [PMID: 34342279 DOI: 10.1107/s205979832100677x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/29/2021] [Indexed: 11/10/2022]
Abstract
α-Glucosidase (EC 3.2.1.20) is a carbohydrate-hydrolyzing enzyme which generally cleaves α-1,4-glycosidic bonds of oligosaccharides and starch from the nonreducing ends. In this study, the novel α-glucosidase from Weissella cibaria BBK-1 (WcAG) was biochemically and structurally characterized. WcAG belongs to glycoside hydrolase family 13 (GH13) and to the neopullanase subfamily. It exhibits distinct hydrolytic activity towards the α-1,4 linkages of short-chain oligosaccharides from the reducing end. The enzyme prefers to hydrolyse maltotriose and acarbose, while it cannot hydrolyse cyclic oligosaccharides and polysaccharides. In addition, WcAG can cleave pullulan hydrolysates and strongly exhibits transglycosylation activity in the presence of maltose. Size-exclusion chromatography and X-ray crystal structures revealed that WcAG forms a homodimer in which the N-terminal domain of one monomer is orientated in proximity to the catalytic domain of another, creating the substrate-binding groove. Crystal structures of WcAG in complexes with maltose, maltotriose and acarbose revealed a remarkable enzyme active site with accessible +2, +1 and -1 subsites, along with an Arg-Glu gate (Arg176-Glu296) in front of the active site. The -2 and -3 subsites were blocked by Met119 and Asn120 from the N-terminal domain of a different subunit, resulting in an extremely restricted substrate preference.
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Affiliation(s)
- Karan Wangpaiboon
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Pasunee Laohawuttichai
- Structural and Computational Biology Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Sun Yong Kim
- Structural Biology Laboratory, Nara Institute of Science and Technology, Takayama, Ikoma, Nara 630-0192, Japan
| | - Tomoyuki Mori
- Structural Biology Laboratory, Nara Institute of Science and Technology, Takayama, Ikoma, Nara 630-0192, Japan
| | - Santhana Nakapong
- Department of Chemistry, Faculty of Science, Ramkhamhaeng University, Bangkok 10240, Thailand
| | - Rath Pichyangkura
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Piamsook Pongsawasdi
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Toshio Hakoshima
- Structural Biology Laboratory, Nara Institute of Science and Technology, Takayama, Ikoma, Nara 630-0192, Japan
| | - Kuakarun Krusong
- Structural and Computational Biology Research Unit, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand
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Santana AG, Díaz-Casado L, Montalvillo L, Jiménez-Moreno E, Mann E, Asensio JL. Aromatic interactions in Glycochemistry: from molecular recognition to catalysis. Curr Med Chem 2021; 29:1208-1218. [PMID: 34254906 DOI: 10.2174/0929867328666210709120216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Revised: 05/05/2021] [Accepted: 05/13/2021] [Indexed: 11/22/2022]
Abstract
Aromatic platforms are ubiquitous recognition motifs occurring in protein carbohydrate binding domains (CBDs), RNA receptors and enzymes. They stabilize the glycoside/receptor complexes by participating in stacking CH/π interactions with either the α- or β- face of the corresponding pyranose units. In addition, the role played by aromatic units in the stabilization of glycoside cationic transition states has started being recognized in recent years. Extensive studies carried out during the last decade have allowed to dissect the main contributing forces that stabilize the carbohydrate/aromatic complexes, while helping delineate not only the standing relationship between the glycoside/aromatic chemical structures and the strength of this interaction, but also their potential influence on glycoside reactivity.
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Affiliation(s)
| | | | | | | | - Enrique Mann
- Instituto de Química Orgánica General (IQOG-CSIC), Madrid, Spain
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31
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Solat N, Shafiei M. A novel pH and thermo-tolerant halophilic alpha-amylase from moderate halophile Nesterenkonia sp. strain F: gene analysis, molecular cloning, heterologous expression and biochemical characterization. Arch Microbiol 2021; 203:3641-3655. [PMID: 33993325 DOI: 10.1007/s00203-021-02359-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 04/27/2021] [Accepted: 05/03/2021] [Indexed: 10/21/2022]
Abstract
A novel pH and thermo-tolerate halophilic alpha-amylase from moderately halophilic bacterium, Nesterenkonia sp.strain F was cloned and expressed in Escherichia coli. 16S rRNA sequence of the strain shared 99.46% similarities with closely related type species. Also, the genome sequence shared ANI values below 92% and dDDH values below 52% with the closely related type species. Consequently, it is proposed that strain F represents a novel species. The AmyF gene was 1390 bp long and encodes an alpha-amylase of 463 amino acid residues with pI of 4.62. The deduced AmyF shared very low sequence similarity (< 24%) with functionally characterized recombinant halophilic alpha-amylases. The recombinant alpha-amylase was successfully purified from Ni-NTA columns with a molecular mass of about 52 KDa on sodium dodecyl sulfate polyacrylamide gel electrophoresis. The enzyme was active over a wide range of temperature (25-75 °C) and pH (4-9) with optimum activity at 45 °C and 7.5, respectively. Also, although it was active over a various concentrations of NaCl and KCl (0-4 M), increasing activity of the enzyme was observed with increasing concentration of these salts. Low concentrations of Ca2+ ion had no activating effect, but high concentrations of the ion (40-200 mM) enhanced activity of AmyF. The enzyme activity was increased by increasing concentrations of Mg2+, Zn2+, Hg2+ and Fe3+. However, it was inhibited only at very high concentrations of these metal ions. Cu2+ did not decrease the amylase activity and the highest activity was observed at 100 mM of the ion. These properties indicate wide potential applications of this recombinant enzyme in starch processing industries. This is the first isolation, cloning and characterization of a gene encoding alpha-amylase from Nesternkonia genus.
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Affiliation(s)
- Nastaran Solat
- Department of Genetics, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran.,Biotechnology and Bioscience Research Center, Shahid Chamran University of Ahvaz, Ahvaz, Iran
| | - Mohammad Shafiei
- Department of Genetics, Faculty of Sciences, Shahid Chamran University of Ahvaz, Ahvaz, Iran. .,Biotechnology and Bioscience Research Center, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
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32
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Güzel E, Koçyiğit ÜM, Taslimi P, Erkan S, Taskin OS. Biologically active phthalocyanine metal complexes: Preparation, evaluation of α-glycosidase and anticholinesterase enzyme inhibition activities, and molecular docking studies. J Biochem Mol Toxicol 2021; 35:1-9. [PMID: 33704864 DOI: 10.1002/jbt.22765] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Revised: 02/01/2021] [Accepted: 03/02/2021] [Indexed: 01/04/2023]
Abstract
In this study, preparation, as well as investigation of α-glycosidase and cholinesterase (ChE) enzyme inhibition activities of furan-2-ylmethoxy-substituted compounds 1-7, are reported. Peripherally, tetra-substituted copper and manganese phthalocyanines (5 and 6) were synthesized for the first time. The substitution of furan-2-ylmethoxy groups provides remarkable solubility to the complex and redshift of the phthalocyanines Q-band. Besides, the inhibitory effects of these compounds on acetylcholinesterase (AChE), butyrylcholinesterase (BChE), and α-glycosidase (α-Gly) enzymes have been investigated. The AChE was inhibited by these compounds (1-7) in low micromolar levels, and K i values were recorded between 11.17 ± 1.03 and 83.28 ± 11.08 µM. Against the BChE, the compounds demonstrated K i values from 7.55 ± 0.98 to 81.35 ± 12.80 µM. Also, these compounds (1-7) effectively inhibited α-glycosidase, with K i values in the range of 744.87 ± 67.33 to 1094.38 ± 88.91 µM. For α-glycosidase, the most effective K i values of phthalocyanines 3 and 6 were with K i values of 744.87 ± 67.33 and 880.36 ± 56.77 µM, respectively. Moreover, the studied metal complexes were docked with target proteins PDB ID: 4PQE, 1P0I, and 3WY1. Pharmacokinetic parameters and secondary chemical interactions that play an active role in interaction were predicted with docking simulation results. Overall, furan-2-ylmethoxy-substituted phthalocyanines can be considered as potential agents for the treatment of Alzheimer's diseases and diabetes mellitus.
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Affiliation(s)
- Emre Güzel
- Department of Fundamental Sciences, Sakarya University of Applied Sciences, Sakarya, Turkey
| | - Ümit M Koçyiğit
- Department of Basic Pharmaceutical Sciences, Sivas Cumhuriyet University, Sivas, Turkey
| | - Parham Taslimi
- Department of Biotechnology, Bartın University, Bartın, Turkey
| | - Sultan Erkan
- Department of Chemistry, Sivas Cumhuriyet University, Sivas, Turkey
| | - Omer S Taskin
- Department of Chemical Oceanography, İstanbul University, İstanbul, Turkey
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Zhou P, Yan S, Lu Y, Li XN, Zhang M, Li Q, Chen X, Wang J, Zhu H, Chen C, Zhang Y. Five new secondary metabolites from the fungus Phomopsis asparagi. Fitoterapia 2021; 150:104840. [PMID: 33535108 DOI: 10.1016/j.fitote.2021.104840] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 01/12/2021] [Accepted: 01/16/2021] [Indexed: 10/22/2022]
Abstract
Five new compounds, including a pair of diphenylcyclopentenone enantiomers (±)-phomopsisin A (1), a sesquiterpenoid 15-hydroxylithocarin A (2), a new diketopiperazine alkaloid prenylcyclotryprostatin A (3) and 7-hydroxy-cis-L(-)-3,6-dibenzyl-2,5-dioxopiperazine (6), along with five known compounds were isolated from the fungus Phomopsis asparagi. Their structures were elucidated on the basis of spectroscopic analyses (1D and 2D NMR), theoretical electronic circular dichroism (ECD) calculation, modified Mosher's method, and X-ray crystallography. The racemates of (±)-phomopsisin A showed inhibition on α-glucosidase with IC50 of 30.07 ± 0.75 μM (positive control acarbose, 121 ± 2.7 μM).
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Affiliation(s)
- Peng Zhou
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China
| | - Shan Yan
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China
| | - Yuanyuan Lu
- Maternal and Child Health Hospital of Hubei Province, Tongji Medical College, Huazhong Universty of Science and Technology, Wuhan 430070, Hubei Province, People's Republic of China
| | - Xiao-Nian Li
- State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, Yunnan Province, People's Republic of China
| | - Mi Zhang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China
| | - Qin Li
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China
| | - Xia Chen
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China
| | - Jianping Wang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China
| | - Hucheng Zhu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China
| | - Chunmei Chen
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China.
| | - Yonghui Zhang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, Hubei Province, People's Republic of China.
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Suzuki T, Fukaya M, Takahashi K, Takeuchi M, Hara R, Ogawa J, Ueda M. Cloning and characterization of a recombinant α-glucosidase from Ensifer adhaerens NBRC 100388 and evaluation of its glucosyl transfer activity. BIOCATALYSIS AND AGRICULTURAL BIOTECHNOLOGY 2020. [DOI: 10.1016/j.bcab.2020.101837] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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The effects of bioactive compounds from blueberry and blackcurrant powders on the inhibitory activities of oat bran pastes against α-amylase and α-glucosidase linked to type 2 diabetes. Food Res Int 2020; 138:109756. [PMID: 33292939 DOI: 10.1016/j.foodres.2020.109756] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2020] [Revised: 09/14/2020] [Accepted: 09/25/2020] [Indexed: 12/27/2022]
Abstract
The α-amylase and α-glucosidase inhibitory activities by extracts of oat bran, blueberry and blackcurrant powders, as well as oat bran pastes supplemented 25% of blueberry and blackcurrant powder, were studied by measuring their half inhibitory (IC50) concentrations. Addition of blueberry or blackcurrant powder into oat bran paste increased α-amylase and α-glucosidase inhibitory activities with a decrease in IC50 values. The main anthocyanidin content was measured by pH differential method and the potential inhibitory mechanisms of these extracts were also investigated by detailed inhibition kinetics and docking simulations. The results showed that: (1) cyanidin and delphinidin were the main anthocyanidin profiles in extracts; (2) only blackcurrant powder was a competitive inhibitor, while other extracts were all mixed-type inhibitors against α-amylase; (3) both blueberry- and blackcurrant-enriched pastes were competitive inhibitors, while other extracts were all mixed-type inhibitors towards α-glucosidase; (4) the α-amylase and α-glucosidase inhibitory activities by extracts were potentially driven by hydrogen bonding, cyanidin-3-glucoside and delphinidin-3-glucoside had stronger binding affinity compared to malvidin-3-glucoside and cyanidin-3-rutinside. This study suggested supplementary of blueberry and blackcurrant with oat bran might be a potential source of bioactive products for antidiabetic activity.
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36
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Structure-function analysis of silkworm sucrose hydrolase uncovers the mechanism of substrate specificity in GH13 subfamily 17 exo-α-glucosidases. J Biol Chem 2020; 295:8784-8797. [PMID: 32381508 PMCID: PMC7324511 DOI: 10.1074/jbc.ra120.013595] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2020] [Revised: 05/05/2020] [Indexed: 01/07/2023] Open
Abstract
The domestic silkworm Bombyx mori expresses two sucrose-hydrolyzing enzymes, BmSUH and BmSUC1, belonging to glycoside hydrolase family 13 subfamily 17 (GH13_17) and GH32, respectively. BmSUH has little activity on maltooligosaccharides, whereas other insect GH13_17 α-glucosidases are active on sucrose and maltooligosaccharides. Little is currently known about the structural mechanisms and substrate specificity of GH13_17 enzymes. In this study, we examined the crystal structures of BmSUH without ligands; in complexes with substrates, products, and inhibitors; and complexed with its covalent intermediate at 1.60-1.85 Å resolutions. These structures revealed that the conformations of amino acid residues around subsite -1 are notably different at each step of the hydrolytic reaction. Such changes have not been previously reported among GH13 enzymes, including exo- and endo-acting hydrolases, such as α-glucosidases and α-amylases. Amino acid residues at subsite +1 are not conserved in BmSUH and other GH13_17 α-glucosidases, but subsite -1 residues are absolutely conserved. Substitutions in three subsite +1 residues, Gln191, Tyr251, and Glu440, decreased sucrose hydrolysis and increased maltase activity of BmSUH, indicating that these residues are key for determining its substrate specificity. These results provide detailed insights into structure-function relationships in GH13 enzymes and into the molecular evolution of insect GH13_17 α-glucosidases.
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Crystal structure of α-glucosyl transfer enzyme XgtA from Xanthomonas campestris WU-9701. Biochem Biophys Res Commun 2020; 526:580-585. [PMID: 32247611 DOI: 10.1016/j.bbrc.2020.03.109] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Revised: 03/17/2020] [Accepted: 03/18/2020] [Indexed: 11/24/2022]
Abstract
The α-glucosyl transfer enzyme XgtA is a novel type α-Glucosidase (EC 3.2.1.20) produced by Xanthomonas campestris WU-9701. One of the unique properties of XgtA is that it shows extremely high α-glucosylation activity toward alcoholic and phenolic -OH groups in compounds using maltose as an α-glucosyl donor and allows for the synthesis of various useful α-glucosides with high yields. XgtA shows no hydrolytic activity toward sucrose and no α-glucosylation activity toward saccharides to produce oligosaccharides. In this report, the crystal structure of XgtA was solved at 1.72 Å resolution. The crystal belonged to space group P22121, with unit-cell parameters a = 73.07, b = 83.48, and c = 180.79 Å. The β→α loop 4 of XgtA, which is proximal to the catalytic center, formed a unique structure that is not observed in XgtA homologs. Furthermore, XgtA was found to contain unique amino acid residues around its catalytic center. The unique structure of XgtA provides an insight into the mechanism for the regulation of substrate specificity in this enzyme.
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Punnatin P, Chanchao C, Chunsrivirot S. Molecular dynamics reveals insight into how N226P and H227Y mutations affect maltose binding in the active site of α-glucosidase II from European honeybee, Apis mellifera. PLoS One 2020; 15:e0229734. [PMID: 32126122 PMCID: PMC7053764 DOI: 10.1371/journal.pone.0229734] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Accepted: 02/12/2020] [Indexed: 11/19/2022] Open
Abstract
European honeybee, Apis mellifera, produces α-glucosidase (HBGase) that catalyzes the cleavage of an α-glycosidic bond of the non-reducing end of polysaccharides and has potential applications for malt hydrolysis in brewing industry. Characterized by their substrate specificities, HBGases have three isoforms including HBGase II, which prefers maltose to sucrose as a substrate. Previous study found that the catalytic efficiency of maltose hydrolysis of N226P mutant of HBGase II was higher than that of the wild type (WT), and the catalytic efficiency of maltose hydrolysis of WT was higher than those of H227Y and N226P-H227Y mutants. We hypothesized that N226P mutation probably caused maltose to bind with better affinity and position/orientation for hydrolysis than WT, while H227Y and N226P-H227Y mutations caused maltose to bind with worse affinity and position/orientation for hydrolysis than WT. Using this hypothesis, we performed molecular dynamics on the catalytically competent binding conformations of maltose/WT, maltose/N226P, maltose/H227Y, and maltose/N226P-H227Y complexes to elucidate effects of N226P and H227Y mutations on maltose binding in HBGase II active site. Our results reasonably support this hypothesis because the N226P mutant had better binding affinity, higher number of important binding residues, strong and medium hydrogen bonds as well as shorter distance between atoms necessary for hydrolysis than WT, while the H227Y and N226P-H227Y mutants had worse binding affinities, lower number of important binding residues and strong hydrogen bonds as well as longer distances between atoms necessary for hydrolysis than WT. Moreover, results of binding free energy and hydrogen bond interaction of residue 227 support the role of H227 as a maltose preference residue, as proposed by previous studies. Our study provides important and novel insight into how N226P and H227Y mutations affect maltose binding in HBGase II active site. This knowledge could potentially be used to engineer HBGase II to improve its efficiency.
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Affiliation(s)
- Panachai Punnatin
- Faculty of Science, Department of Biology, Chulalongkorn University, Pathumwan, Bangkok, Thailand
- Faculty of Science, Structural and Computational Biology Research Unit, Department of Biochemistry, Chulalongkorn University, Pathumwan, Bangkok, Thailand
| | - Chanpen Chanchao
- Faculty of Science, Department of Biology, Chulalongkorn University, Pathumwan, Bangkok, Thailand
| | - Surasak Chunsrivirot
- Faculty of Science, Structural and Computational Biology Research Unit, Department of Biochemistry, Chulalongkorn University, Pathumwan, Bangkok, Thailand
- Faculty of Science, Department of Biochemistry, Chulalongkorn University, Pathumwan, Bangkok, Thailand
- * E-mail:
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Cytotoxicity, alpha-glucosidase inhibition and molecular docking studies of hydroxamic acid chromium(III) complexes. J Biol Inorg Chem 2020; 25:239-252. [DOI: 10.1007/s00775-020-01755-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Accepted: 01/09/2020] [Indexed: 12/17/2022]
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Synthesis, biological activity and molecular modeling of a new series of condensed 1,2,4-triazoles. Bioorg Chem 2019; 92:103193. [PMID: 31445196 DOI: 10.1016/j.bioorg.2019.103193] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/10/2019] [Accepted: 08/10/2019] [Indexed: 12/30/2022]
Abstract
A ring transformation of 6-methyl-7H[1,2,4]triazolo [4,3-b][1,2,4] triazepine-8(9H)-ones (thiones) in the presence of acetic anhydride give rise to a new series of 17 condensed 1,2,4-triazole derivatives (1-17). Plausible mechanisms are proposed and show the formation of a beta fused β-lactam moiety. The compounds were tested for their (i) inhibitory potential on digestive enzymes (α-amylase and α-glucosidase), and (ii) antioxidant activity using radical scavenging (DPPH and ABTS radicals) and ferric reducing power assays. The compounds showed interesting and promising antidiabetic activities compared to the reference drug Acarbose. Molecular docking study has been carried out to determine the binding mode interactions between these derivatives and the targeted enzymes. The results showed the strength of intermolecular hydrogen bonding in ligand-receptor complexes as an important descriptor in rationalizing the observed inhibition results. Moreover, molecular dynamics simulations are also performed for the best protein-ligand complex to understand the stability of small molecule in a protein environment. To shed light on the antioxidant activity of the synthesized compounds and the mechanism involved in DPPH free radical, DFT calculations were performed at the B3P86/6-311++G(d,p) level using the polarizable continuum model. The effect of aprotic solvent on bond dissociation enthalpies (BDEs) is investigated by calculating and comparing BDEs of 1 in methanol and dimethylsulfoxide as solvents using PCM. The obtained results show that the mechanism of action depends on the basic skeleton and the presence of substituted functional groups in these derivatives. BDEs are found to be slightly influenced by the aprotic solvent of less than 0.01 kcal/mol compared with those obtained in methanol.
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Patel N, Prajapati A, Jadeja R, Patel R, Patel S, Gupta V, Tripathi I, Dwivedi N. Model investigations for vanadium-protein interactions: Synthesis, characterization and antidiabetic properties. Inorganica Chim Acta 2019. [DOI: 10.1016/j.ica.2019.04.050] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Ernits K, Eek P, Lukk T, Visnapuu T, Alamäe T. First crystal structure of an endo-levanase - the BT1760 from a human gut commensal Bacteroides thetaiotaomicron. Sci Rep 2019; 9:8443. [PMID: 31186460 PMCID: PMC6560043 DOI: 10.1038/s41598-019-44785-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Accepted: 05/24/2019] [Indexed: 01/05/2023] Open
Abstract
The endo-levanase BT1760 of a human gut commensal Bacteroides thetaiotaomicron randomly cuts a β-2,6-linked fructan, levan, into fructo-oligosaccharides providing a prebiotic substrate for gut microbiota. Here we introduce the crystal structure of BT1760 at resolution of 1.65 Å. The fold of the enzyme is typical for GH32 family proteins: a catalytic N-terminal five-bladed β-propeller connected with a C-terminal β-sandwich domain. The levantetraose-bound structure of catalytically inactive mutant E221A at 1.90-Å resolution reveals differences in substrate binding between the endo-acting fructanases. A shallow substrate-binding pocket of the endo-inulinase INU2 of Aspergillus ficuum binds at least three fructose residues at its flat bottom. In the levantetraose-soaked crystal of the endo-levanase E221A mutant the ligand was bent into the pond-like substrate pocket with its fructose residues making contacts at −3, −2, −1 and + 1 subsites residing at several pocket depths. Binding of levantetraose to the β-sandwich domain was not detected. The N- and C-terminal modules of BT1760 did not bind levan if expressed separately, the catalytic domain lost its activity and both modules tended to precipitate. We gather that endo-levanase BT1760 requires both domains for correct folding, solubility and stability of the protein.
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Affiliation(s)
- Karin Ernits
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia
| | - Priit Eek
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Tiit Lukk
- Department of Chemistry and Biotechnology, Tallinn University of Technology, Akadeemia tee 15, 12618, Tallinn, Estonia
| | - Triinu Visnapuu
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia
| | - Tiina Alamäe
- Department of Genetics, Institute of Molecular and Cell Biology, University of Tartu, Riia 23, 51010, Tartu, Estonia.
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Balbaa M, Awad D, Elaal AA, Mahsoub S, Moharram M, Sadek O, Rezki N, Aouad MR, Badawy METI, El Ashry ESH. Action of Thioglycosides of 1,2,4-Triazoles and Imidazoles on the Oxidative Stress and Glycosidases in Mice with Molecular Docking. LETT DRUG DES DISCOV 2019. [DOI: 10.2174/1573413715666181212150955] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Background:
,2,3-Triazoles and imidazoles are important five-membered heterocyclic
scaffolds due to their extensive biological activities. These products have been an area of growing
interest to many researchers around the world because of their enormous pharmaceutical scope.
Methods:
The in vivo and in vitro enzyme inhibition of some thioglycosides encompassing 1,2,4-
triazole N1, N2, and N3 and/or imidazole moieties N4, N5, and N6. The effect on the antioxidant
enzymes (superoxide dismutase, glutathione S-transferase, glutathione peroxidase and catalase) was
investigated as well as their effect on α-glucosidase and β-glucuronidase. Molecular docking studies
were carried out to investigate the mode of the binding interaction of the compounds with α-
glucosidase and β -glucuronidase. In addition, quantitative structure-activity relationship (QSAR)
investigation was applied to find out the correlation between toxicity and physicochemical properties.
Results:
The decrease of the antioxidant status was revealed by the in vivo effect of the tested compounds.
Furthermore, the in vivo and in vitro inhibitory effects of the tested compounds were clearly
pronounced on α-glucosidase, but not β-glucuronidase. The IC50 and Ki values revealed that the thioglycoside
- based 1,2,4-triazole N3 possesses a high inhibitory action. In addition, the in vitro studies
demonstrated that the whole tested 1,2,4-triazole are potent inhibitors with a Ki magnitude of 10-6
and exhibited a competitive type inhibition. On the other hand, the thioglycosides - based imidazole
ring showed an antioxidant activity and exerted a slight in vivo stimulation of α-glucosidase and β-
glucuronidase. Molecular docking proved that the compounds exhibited binding affinity with the
active sites of α -glucosidase and β-glucuronidase (docking score ranged from -2.320 to -4.370
kcal/mol). Furthermore, QSAR study revealed that the HBD and RB were found to have an overall
significant correlation with the toxicity.
Conclusion:
These data suggest that the inhibition of α-glucosidase is accompanied by an oxidative
stress action.
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Affiliation(s)
- Mahmoud Balbaa
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Doaa Awad
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Ahmad Abd Elaal
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Shimaa Mahsoub
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Mayssaa Moharram
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Omayma Sadek
- Department of Biochemistry, Faculty of Science, Alexandria University, Alexandria, Egypt
| | - Nadjet Rezki
- Department of Chemistry, Faculty of Science, Taibah University, Al-Madinah AlMunawarah 30002, Saudi Arabia
| | - Mohamed Reda Aouad
- Department of Chemistry, Faculty of Science, Taibah University, Al-Madinah AlMunawarah 30002, Saudi Arabia
| | - Mohamed El-Taher Ibrahim Badawy
- Department of Pesticide Chemistry and Technology, Faculty of Agriculture, 21545-El-Shatby, Alexandria University, Alexandria, Egypt
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Liu M, Qi C, Sun W, Shen L, Wang J, Liu J, Lai Y, Xue Y, Hu Z, Zhang Y. α-Glucosidase Inhibitors From the Coral-Associated Fungus Aspergillus terreus. Front Chem 2018; 6:422. [PMID: 30271773 PMCID: PMC6146087 DOI: 10.3389/fchem.2018.00422] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2018] [Accepted: 08/24/2018] [Indexed: 12/15/2022] Open
Abstract
Nine novel butenolide derivatives, including four pairs of enantiomers, named (±)-asperteretones A-D (1a/1b-4a/4b), and a racemate, named asperteretone E (5), were isolated and identified from the coral-associated fungus Aspergillus terreus. All the structures were established based on extensive spectroscopic analyses, including HRESIMS and NMR data. The chiral chromatography analyses allowed the separation of (±)-asperteretones A-D, whose absolute configurations were further confirmed by experimental and calculated electronic circular dichroism (ECD) analysis. Structurally, compounds 2-5 represented the first examples of prenylated γ-butenolides bearing 2-phenyl-3-benzyl-4H-furan-1-one motifs, and their crucial biogenetically related metabolite, compound 1, was uniquely defined by an unexpected cleavage of oxygen bridge between C-1 and C-4. Importantly, (±)-asperteretal D and (4S)-4-decarboxylflavipesolide C were revised to (±)-asperteretones B (2a/2b) and D (4), respectively. Additionally, compounds 1a/1b-4a/4b and 5 were evaluated for the α-glucosidase inhibitory activity, and all these compounds exhibited potent inhibitory potency against α-glucosidase, with IC50 values ranging from 15.7 ± 1.1 to 53.1 ± 1.4 μM, which was much lower than that of the positive control acarbose (IC50 = 154.7 ± 8.1 μM), endowing them as promising leading molecules for the discovery of new α-glucosidase inhibitors for type-2 diabetes mellitus treatment.
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Affiliation(s)
- Mengting Liu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Changxing Qi
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Weiguang Sun
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ling Shen
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jianping Wang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Junjun Liu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yongji Lai
- Department of Pharmacy, the Central Hospital of Wuhan, Wuhan, China
| | - Yongbo Xue
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhengxi Hu
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yonghui Zhang
- Hubei Key Laboratory of Natural Medicinal Chemistry and Resource Evaluation, School of Pharmacy, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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Sharma M, Lakshmi A, Gupta GD, Kumar V. Mosquito-larvicidal binary toxin receptor protein (Cqm1): crystallization and X-ray crystallographic analysis. Acta Crystallogr F Struct Biol Commun 2018; 74:571-577. [PMID: 30198890 PMCID: PMC6130429 DOI: 10.1107/s2053230x18010671] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/24/2018] [Indexed: 11/10/2022] Open
Abstract
Cqm1 from Culex quinquefasciatus has been identified as the receptor for Lysinibacillus sphaericus binary toxin (BinAB). It is an amylomaltase that is presented on the epithelial membrane in the larval midgut through a glycosyl-phosphatidylinositol anchor. The active core of this protein (residues 23-560) was overexpressed in Escherichia coli, purified and successfully crystallized by the sitting-drop vapor-diffusion method using D-arabinose and CaCl2 as additives, as identified using high-throughput differential scanning fluorimetry analysis. X-ray diffraction data were collected to a resolution of 2.8 Å using a laboratory X-ray source. The crystals had the symmetry of space group P212121, with unit-cell parameters a = 191.3, b = 205.3, c = 59.0 Å and with four monomers in the asymmetric unit. Structure refinement is in progress. This is the first structure report for a binary toxin receptor and for a member of the GH13_17 subfamily in the CAZy database.
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Affiliation(s)
- Mahima Sharma
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, Maharashtra 400 094, India
| | - Ashwitha Lakshmi
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085, India
| | - Gagan D. Gupta
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, Maharashtra 400 094, India
| | - Vinay Kumar
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai, Maharashtra 400 085, India
- Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai, Maharashtra 400 094, India
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El Bakri Y, Anouar EH, Marmouzi I, Sayah K, Ramli Y, El Abbes Faouzi M, Essassi EM, Mague JT. Potential antidiabetic activity and molecular docking studies of novel synthesized 3.6-dimethyl-5-oxo-pyrido[3,4-f][1,2,4]triazepino[2,3-a]benzimidazole and 10-amino-2-methyl-4-oxo pyrimido[1,2-a]benzimidazole derivatives. J Mol Model 2018; 24:179. [PMID: 29951869 DOI: 10.1007/s00894-018-3705-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2017] [Accepted: 06/06/2018] [Indexed: 11/25/2022]
Abstract
Diabetes affects a large population of the globe and is considered as a leading cause of death. Many synthetic and natural inhibitors have been developed for diabetes treatment. Herein, we report the potential antidiabetic activity of two new heterocyclic systems, namely 3.6-dimethyl-5-oxo-pyrido[3,4f][1,2,4]triazepino[2,3-a]benzimidazole (I) and 10-amino-2-methyl-4-oxo pyrimido[1,2-a]benzimidazole (II) against three related enzymes: α-amylase, α-glucosidase and β-galactosidase. Compounds I and II were synthesized by the action of DMF-DMA and dimethyl sulfate in the presence of water on 2-methyl-3H-benzimidazolo[1,2b][1,2,4]triazepin-4(5H)-one, and are characterized by single X-ray diffraction. The binding interaction modes in the active sites of I and II and targeted enzymes (stable complexes ligand-receptor) are emphasized using the molecular docking approach by applying the Lamarckian genetic algorithm method. Furthermore, plausible mechanisms have been proposed explaining their synthesis. Hirshfeld surface analysis reveals the nature of molecular interactions and fingerprint plots provide information about the percentage contribution from each individual molecular contact to the structure surface. Graphical abstract Left Molecular packing of 1,4-dimethyl-2-oxo-pyrimido[1,2-a]benzimidazole hydrate. Right Docking active site of α-glucosidase.
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Affiliation(s)
- Youness El Bakri
- Laboratoire de Chimie Organique Hétérocyclique, Centre de Recherche des Sciences des Médicaments, Pôle de Compétences Pharmacochimie, URAC 21, Faculté des Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 10014, Rabat, Morocco.
| | - El Hassane Anouar
- Department of Chemistry, College of Science and Humanities, Prince Sattam bin Abdulaziz University, AlKharj, Saudi Arabia.
| | - Ilias Marmouzi
- Faculté de Médicine et de Pharmacie, Laboratoire de Pharmacologie et Toxicologie, équipe de Pharmacocinétique, University Mohammed V in Rabat, BP 6203, Rabat Instituts, Rabat, Morocco
| | - Karima Sayah
- Faculté de Médicine et de Pharmacie, Laboratoire de Pharmacologie et Toxicologie, équipe de Pharmacocinétique, University Mohammed V in Rabat, BP 6203, Rabat Instituts, Rabat, Morocco
| | - Youssef Ramli
- Medicinal Chemistry Laboratory, Faculty of Medicine and Pharmacy, Mohammed V University in Rabat, 10170, Rabat, Morocco
| | - My El Abbes Faouzi
- Faculté de Médicine et de Pharmacie, Laboratoire de Pharmacologie et Toxicologie, équipe de Pharmacocinétique, University Mohammed V in Rabat, BP 6203, Rabat Instituts, Rabat, Morocco
| | - El Mokhtar Essassi
- Laboratoire de Chimie Organique Hétérocyclique, Centre de Recherche des Sciences des Médicaments, Pôle de Compétences Pharmacochimie, URAC 21, Faculté des Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 10014, Rabat, Morocco
| | - Joel T Mague
- Department of Chemistry, Tulane University, New Orleans, LA, 70118, USA
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Auiewiriyanukul W, Saburi W, Kato K, Yao M, Mori H. Function and structure of GH13_31 α-glucosidase with high α-(1→4)-glucosidic linkage specificity and transglucosylation activity. FEBS Lett 2018; 592:2268-2281. [PMID: 29870070 DOI: 10.1002/1873-3468.13126] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 05/11/2018] [Accepted: 05/22/2018] [Indexed: 11/12/2022]
Abstract
α-Glucosidase hydrolyzes α-glucosides and transfers α-glucosyl residues to an acceptor through transglucosylation. In this study, GH13_31 α-glucosidase BspAG13_31A with high transglucosylation activity is reported in Bacillus sp. AHU2216 and biochemically and structurally characterized. This enzyme is specific to α-(1→4)-glucosidic linkage as substrates and transglucosylation products. Maltose is the most preferred substrate. Crystal structures of BspAG13_31A wild-type for the substrate-free form and inactive acid/base mutant E256Q in complexes with maltooligosaccharides were solved at 1.6-2.5 Å resolution. BspAG13_31A has a catalytic domain folded by an (β/α)8 -barrel. In subsite +1, Ala200 and His203 on β→α loop 4 and Asn258 on β→α loop 5 are involved in the recognition of maltooligosaccharides. Structural basis for specificity of GH13_31 enzymes to α-(1→4)-glucosidic linkage is first described.
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Affiliation(s)
| | - Wataru Saburi
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
| | - Koji Kato
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Min Yao
- Faculty of Advanced Life Science, Hokkaido University, Sapporo, Japan
| | - Haruhide Mori
- Research Faculty of Agriculture, Hokkaido University, Sapporo, Japan
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Na Ayutthaya PP, Chanchao C, Chunsrivirot S. Insight into the substrate specificity change caused by the Y227H mutation of α-glucosidase III from the European honeybee (Apis mellifera) through molecular dynamics simulations. PLoS One 2018; 13:e0198484. [PMID: 29864156 PMCID: PMC5986129 DOI: 10.1371/journal.pone.0198484] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Accepted: 05/18/2018] [Indexed: 01/12/2023] Open
Abstract
Honey from the European honeybee, Apis mellifera, is produced by α-glucosidases (HBGases) and is widely used in food, pharmaceutical, and cosmetic industries. Categorized by their substrate specificities, HBGases have three isoforms: HBGase I, II and III. Previous experimental investigations showed that wild-type HBGase III from Apis mellifera (WT) preferred sucrose to maltose as a substrate, while the Y227H mutant (MT) preferred maltose to sucrose. This mutant can potentially be used for malt hydrolysis because it can efficiently hydrolyze maltose. In this work, to elucidate important factors contributing to substrate specificity of this enzyme and gain insight into how the Y227H mutation causes substrate specificity change, WT and MT homology models were constructed, and sucrose/maltose was docked into active sites of the WT and MT. AMBER14 was employed to perform three independent molecular dynamics runs for these four complexes. Based on the relative binding free energies calculated by the MM-GBSA method, sucrose is better than maltose for WT binding, while maltose is better than sucrose for MT binding. These rankings support the experimentally observed substrate specificity that WT preferred sucrose to maltose as a substrate, while MT preferred maltose to sucrose, suggesting the importance of binding affinity for substrate specificity. We also found that the Y227H mutation caused changes in the proximities between the atoms necessary for sucrose/maltose hydrolysis that may affect enzyme efficiency in the hydrolysis of sucrose/maltose. Moreover, the per-residue binding free energy decomposition results show that Y227/H227 may be a key residue for preference binding of sucrose/maltose in the WT/MT active site. Our study provides important and novel insight into the binding of sucrose/maltose in the active site of Apis mellifera HBGase III and into how the Y227H mutation leads to the substrate specificity change at the molecular level. This knowledge could be beneficial in the design of this enzyme for increased production of desired products.
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Affiliation(s)
- Pratchaya Pramoj Na Ayutthaya
- Department of Biology, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, Thailand
- Structural and Computational Biology Research Group, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, Thailand
| | - Chanpen Chanchao
- Department of Biology, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, Thailand
| | - Surasak Chunsrivirot
- Structural and Computational Biology Research Group, Department of Biochemistry, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, Thailand
- Department of Biochemistry, Faculty of Science, Chulalongkorn University, Pathumwan, Bangkok, Thailand
- * E-mail:
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Sharma M, Gupta GD, Kumar V. Receptor protein of Lysinibacillus sphaericus mosquito-larvicidal toxin displays amylomaltase activity. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2018; 93:37-46. [PMID: 29229337 DOI: 10.1016/j.ibmb.2017.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Revised: 10/20/2017] [Accepted: 12/03/2017] [Indexed: 06/07/2023]
Abstract
The activated binary toxin (BinAB) from Lysinibacillus sphaericus binds to surface receptor protein (Cqm1) on the midgut cell membrane and kills Culex quinquefasciatus larvae on internalization. Cqm1 is attached to cells via a glycosyl-phosphatidylinositol (GPI) anchor. It has been classified as a member of glycoside hydrolase family 13 of the CAZy database. Here, we report characterization of the ordered domain (residues 23-560) of Cqm1. Gene expressing Cqm1 of BinAB susceptible mosquito was chemically synthesized and the protein was purified using E. coli expression system. Values for the Michaelis-Menten kinetics parameters towards 4-nitrophenyl α-D-glucopyranoside (α-pNPG) substrate were estimated to be 0.44 mM (Km) and 1.9 s-1 (kcat). Thin layer chromatography experiments established Cqm1 as α-glucosidase competent to cleave α-1,4-glycosidic bonds of maltose and maltotriose with high glycosyltransferase activity to form glucose-oligomers. The observed hydrolysis and synthesis of glucose-oligomers is consistent with open and accessible active-site in the structural model. The protein also hydrolyses glycogen and sucrose. These activities suggest that Cqm1 may be involved in carbohydrate metabolism in mosquitoes. Further, toxic BinA component does not inhibit α-glucosidase activity of Cqm1, while BinB reduced the activity by nearly 50%. The surface plasmon resonance study reveals strong binding of BinB with Cqm1 (Kd, 9.8 nM). BinA interaction with Cqm1 however, is 1000-fold weaker. Notably the estimated Kd values match well with dissociation constants reported earlier with larvae brush border membrane fractions. The Cqm1 protein forms a stable dimer that is consistent with its apical localization in lipid rafts. Its melting temperature (Tm) as observed by thermofluor-shift assay is 51.5 °C and Ca2+ provides structural stability to the protein.
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Affiliation(s)
- Mahima Sharma
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Gagan D Gupta
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India
| | - Vinay Kumar
- Radiation Biology & Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085, India; Homi Bhabha National Institute, Training School Complex, Anushaktinagar, Mumbai 400094, India.
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Chow SY, Wang YL, Hsieh YC, Lee GC, Liaw SH. The N253F mutant structure of trehalose synthase from Deinococcus radioduransreveals an open active-site topology. Acta Crystallogr F Struct Biol Commun 2017; 73:588-594. [DOI: 10.1107/s2053230x17014303] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Accepted: 10/03/2017] [Indexed: 11/11/2022] Open
Abstract
Trehalose synthase (TS) catalyzes the reversible conversion of maltose to trehalose and belongs to glycoside hydrolase family 13 (GH13). Previous mechanistic analysis suggested a rate-limiting protein conformational change, which is probably the opening and closing of the active site. Consistently, crystal structures ofDeinococcus radioduransTS (DrTS) in complex with the inhibitor Tris displayed an enclosed active site for catalysis of the intramoleular isomerization. In this study, the apo structure of the DrTS N253F mutant displays a new open conformation with an empty active site. Analysis of these structures suggests that substrate binding induces a domain rotation to close the active site. Such a substrate-induced domain rotation has also been observed in some other GH13 enzymes.
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