1
|
Jiang YY, Li Y, Chen C, Xin YX. Computational Study on Flavin-Catalyzed Aerobic Dioxygenation of Alkenyl Thioesters: Decomposition of Anionic Peroxides. J Org Chem 2024. [PMID: 39276183 DOI: 10.1021/acs.joc.4c01346] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/16/2024]
Abstract
Flavin-dependent catalysts are widely applied to aerobic monooxygenation/oxidation reactions. In contrast, flavin-catalyzed aerobic dioxygenation reactions exhibit higher atomic economy but are less reported, not to mention the relevant mechanistic studies. Herein, a density functional theory study on flavin-catalyzed aerobic epoxidation-oxygenolysis of alkenyl thioesters was performed for the first time. Different from the previous mechanistic proposal, a pathway featuring two catalytic stages, monoanionic flavin-C(4a)-peroxide/oxide intermediates, and a reverse reaction sequence (epoxidation goes prior to oxygenolysis) was revealed. In comparison, the pathways involving dianionic flavin catalysts, monoanionic flavin-N(5)-(hydro)peroxide/C(10a)-peroxide, or neutral flavin-C(4a)-hydroperoxide/hydroxide/N(5)-oxide, and the pathways where oxygenolysis goes prior to epoxidation are less favored. Epoxidation goes through intramolecular substitution of the O-O bond of anionic flavin-C(4a)-peroxide by β-carbon, while the resulting flavin-C(4a)-oxide accomplishes the oxygenolysis. Furthermore, two other reaction modes, i.e., concerted O-O cleavage/1,2-shift of α-substituents and dyotropic rearrangement were discovered for the decomposition of other anionic peroxides, and preliminary rules were summarized for understanding the chemoselectivity for this process. This study sheds light on the different reaction features of numerous flavin-dioxygen derivatives, providing deeper insights into flavin-catalyzed dioxygenation reactions, and is expected to inspire experimental design based on unconventional anionic peroxides.
Collapse
Affiliation(s)
- Yuan-Ye Jiang
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Yu Li
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Chao Chen
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| | - Yi-Xuan Xin
- School of Chemistry and Chemical Engineering, Qufu Normal University, Qufu 273165, P. R. China
| |
Collapse
|
2
|
Fındık V, Varınca Gerçik BT, Sinek Ö, Erdem SS, Ruiz-López MF. Mechanistic Investigation of Lysine-Targeted Covalent Inhibition of PI3Kδ via ONIOM QM:QM Computations. J Chem Inf Model 2022; 62:6775-6787. [PMID: 35980989 DOI: 10.1021/acs.jcim.2c00569] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Phosphoinositide 3-kinase (PI3K) enzymes are important drug targets, especially in oncology, and several inhibitors are currently under investigation in clinical trials for the treatment of lymphocytic leukemia, follicular lymphoma, breast, thyroid, colorectal, and lung cancer. Targeted covalent inhibitors hold significant promise for drug discovery research especially for kinases. Targeting the lysine residues attracts attention as a new strategy in designing targeted covalent inhibitors, since the lysine residue provides several advantages over the traditional cysteine residue. Recently, new highly selective covalent inhibitors of PI3Kδ with activated ester warheads, targeting the conserved Lys779 residue, were reported. Based on the observed kinetics, a covalent inhibition mechanism was proposed, but the atomistic details of the reaction are still not understood. Therefore, in the present work, we have conducted quantum chemical ONIOM M06-2X/6-31+G(d,p):PM6 calculations on the active site cluster structure of PI3Kδ to elucidate the microscopic details of the mechanism of the aminolysis reaction between Lys779 and the ester inhibitors. Our calculations clearly discriminate the noncovalent methyl ester inhibitor and the covalent inhibitors with activated phenolic esters. For the representative p-NO2, p-F, p-H, and p-OCH3 phenolic esters, the Gibbs free energy profiles of alternative mechanistic paths through either Asp782 or Asp911 demonstrate the modulatory role of active site aspartate residues. The most plausible path alters depending on the electron-withdrawing/donating nature of the p-substituted phenolate leaving group. Inhibitors with sufficiently strong electron-withdrawing group prefer direct dissociation of the leaving group from the tetrahedral zwitterion intermediate, while the ones with electron-donating group favor the formation of a neutral tetrahedral intermediate prior to the dissociation. The relative Gibbs free energy barriers of p-NO2 < p-F < p-H < p-OCH3 substituted phenyl esters display the same qualitative trend as the experimentally measured kinact/KI values. Our results provide in depth insight into the mechanism, which can pave the way for optimizing the inhibitor efficiency.
Collapse
Affiliation(s)
- Volkan Fındık
- LPCT, UMR 7019, University of Lorraine, CNRS, 54000, Nancy, France.,Department of Chemistry, Faculty of Arts and Sciences, Marmara University, 34722, Istanbul, Turkey
| | | | - Öykü Sinek
- Department of Chemistry, Faculty of Arts and Sciences, Marmara University, 34722, Istanbul, Turkey
| | - Safiye Sağ Erdem
- Department of Chemistry, Faculty of Arts and Sciences, Marmara University, 34722, Istanbul, Turkey
| | | |
Collapse
|
3
|
Yang Y, Luo X, Xie Y, Li X, Liu S, Liu N, Chen X. Regulation of different protonated states of two intimate histidine residues on the reductive half-reaction of glucose oxidase. Phys Chem Chem Phys 2022; 24:25788-25800. [PMID: 36263785 DOI: 10.1039/d2cp03502b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Glucose oxidase (GOx) can catalyze the oxidation of β-D-glucose under mild conditions to directly convert biological energy into electrical energy, which has great potential for applications in the fields of enzyme biofuel cells and glucose biosensors. In enzymatic biofuel cells, GOx is often used as an anodic catalyst to improve the performance. The important role of two intimate histidine residues, His505 and His548 (PDB code 4YNU), in the GOx active center has been highlighted in the catalytic oxidation of β-D-glucose, but there is still a lack of systematic examination on the influence of different protonated states of His505 and His548 on the catalytic oxidation of β-D-glucose in GOx. Therefore, in the present work, the GOx active center under the possible protonated states of His548 and His505 is systematically examined by using ONIOM calculations, as well as the influence of remote Arg210 is considered. The calculations reveal that the intimate His505 and His548 can modulate the interaction of the β-D-glucose substrate with isoalloxazine and then control the deprotonization of the hydroxyl group bound to the anomeric carbon of β-D-glucose like controllers. The remote Arg210 provides the driving force for the transfer of two electrons from β-D-glucose to isoalloxazine of FAD via the long-range electrostatic attraction like a horse. Specially, the protonated His505 can serve as a good helper of Arg210 to promote the occurring of the two-proton-coupled two-electron transfer from β-D-glucose to isoalloxazine and His548 in the active center of GOx. These findings provide much insight into the catalytic reactions of GOx in a low pH environment, which may be beneficial to expand the applications of GOx.
Collapse
Affiliation(s)
- Yuning Yang
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China.
| | - Xin Luo
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China.
| | - Yuxin Xie
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China.
| | - Xin Li
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China.
| | - Sijun Liu
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China.
| | - Nian Liu
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China.
| | - Xiaohua Chen
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, P. R. China.
| |
Collapse
|
4
|
Qin X, Chen X. Remote Water-Mediated Proton Transfer Triggers Inter-Cu Electron Transfer: Nitrite Reduction Activation in Copper-Containing Nitrite Reductase. Chembiochem 2021; 22:1405-1414. [PMID: 33295048 DOI: 10.1002/cbic.202000644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 12/07/2020] [Indexed: 11/05/2022]
Abstract
The copper-containing nitrite reductase (CuNiR) catalyzes the biological conversion of nitrite to nitric oxide; key long-range electron/proton transfers are involved in the catalysis. However, the details of the electron-/proton-transfer mechanism are still unknown. In particular, the driving force of the electron transfer from the type-1 copper (T1Cu) site to the type-2 copper (T2Cu) site is ambiguous. Here, we explored the two possible proton-transfer channels, the high-pH proton channel and the primary proton channel, by using two-layered ONIOM calculations. Our calculation results reveal that the driving force for electron transfer from T1Cu to T2Cu comes from a remote water-mediated triple-proton-coupled electron-transfer mechanism. In the high-pH proton channel, the water-mediated triple-proton transfer occurs from Glu113 to an intermediate water molecule, whereas in the primary channel, the transfer is from Lys128 to His260. Subsequently, the two channels employ another two or three distinct proton-transfer steps to deliver the proton to the nitrite substrate at the T2Cu site. These findings explain the detailed proton-/electron-transfer mechanisms of copper-containing nitrite reductase and could extend our understanding of the diverse proton-coupled electron-transfer mechanisms in complicated proteins.
Collapse
Affiliation(s)
- Xin Qin
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, 55 University City South Road, Shapingba District, Chongqing, 401331, P. R. China.,National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, Chongqing University, Chongqing, 401331, P. R. China
| | - Xiaohua Chen
- Chongqing Key Laboratory of Theoretical and Computational Chemistry, School of Chemistry and Chemical Engineering, Chongqing University, 55 University City South Road, Shapingba District, Chongqing, 401331, P. R. China.,National-Municipal Joint Engineering Laboratory for Chemical Process Intensification and Reaction, Chongqing University, Chongqing, 401331, P. R. China
| |
Collapse
|
5
|
Sriwaiyaphram K, Punthong P, Sucharitakul J, Wongnate T. Structure and function relationships of sugar oxidases and their potential use in biocatalysis. Enzymes 2020; 47:193-230. [PMID: 32951824 DOI: 10.1016/bs.enz.2020.05.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Several sugar oxidases that catalyze the oxidation of sugars have been isolated and characterized. These enzymes can be classified as flavoenzyme due to the presence of flavin adenine dinucleotide (FAD) as a cofactor. Sugar oxidases have been proposed to be the key biocatalyst in biotransformation of carbohydrates which can potentially convert sugars to provide a pool of intermediates for synthesis of rare sugars, fine chemicals and drugs. Moreover, sugar oxidases have been applied in biosensing of various biomolecules in food industries, diagnosis of diseases and environmental pollutant detection. This review provides the discussions on general properties, current mechanistic understanding, structural determination, biocatalytic application, and biosensor integration of representative sugar oxidase enzymes, namely pyranose 2-oxidase (P2O), glucose oxidase (GO), hexose oxidase (HO), and oligosaccharide oxidase. The information regarding the relationship between structure and function of these sugar oxidases points out the key properties of this particular group of enzymes that can be modified by engineering, which had resulted in a remarkable economic importance.
Collapse
Affiliation(s)
- Kanokkan Sriwaiyaphram
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | - Pangrum Punthong
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand
| | - Jeerus Sucharitakul
- Department of Biochemistry, Faculty of Dentistry, Chulalongkorn University, Bangkok, Thailand
| | - Thanyaporn Wongnate
- School of Biomolecular Science and Engineering, Vidyasirimedhi Institute of Science and Technology (VISTEC), Rayong, Thailand.
| |
Collapse
|
6
|
Engineering glucose oxidase for bioelectrochemical applications. Bioelectrochemistry 2019; 128:218-240. [DOI: 10.1016/j.bioelechem.2019.04.015] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 04/16/2019] [Accepted: 04/16/2019] [Indexed: 01/18/2023]
|