1
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Panda S, Rout M, Mishra S, Turuk J, Pati S, Dehury B. Molecular docking and MD simulations reveal protease inhibitors block the catalytic residues in Prp8 intein of Aspergillus fumigatus: a potential target for antimycotics. J Biomol Struct Dyn 2023:1-16. [PMID: 38149850 DOI: 10.1080/07391102.2023.2298735] [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: 10/03/2023] [Accepted: 12/18/2023] [Indexed: 12/28/2023]
Abstract
Resistance to azoles and amphotericin B especially in Aspergillus fumigatus is a growing concern towards the treatment of invasive fungal infection. At this critical juncture, intein splicing would be a productive, and innovative target to establish therapies against resistant strains. Intein splicing is the central event for the activation of host protein, essential for the growth and survival of various microorganisms including A. fumigatus. The splicing process is a four-step protease-like nucleophilic cascade. Thus, we hypothesise that protease inhibitors would successfully halt intein splicing and potentially restrict the growth of the aforementioned pathogen. Using Rosetta Fold and molecular dynamics simulations, we modelled Prp8 intein structure; resembling classic intein fold with horse shoe shaped splicing domain. To fully comprehend the active site of Afu Prp8 intein, C1, T62, H65, H818, N819 from intein sequences and S820, the first C-extein residue are selected. Molecular docking shows that two FDA-approved drugs, i.e. Lufotrelvir and Remdesivir triphosphate efficiently interact with Prp8 intein from the assortment of 212 protease inhibitors. MD simulation portrayed that Prp8 undergoes conformational change upon ligand binding, and inferred the molecular recognition and stability of the docked complexes. Per-residue decomposition analysis confirms the importance of F: block R802, V803, and Q807 binding pocket in intein splicing domain towards recognition of inhibitors, along with active site residues through strong hydrogen bonds and hydrophobic contacts. However, in vitro and in vivo assays are required to confirm the inhibitory action on Prp8 intein splicing; which may pave the way for the development of new antifungals for A. fumigatus.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Sunita Panda
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Madhusmita Rout
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Sarbani Mishra
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Jyotirmayee Turuk
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Sanghamitra Pati
- Mycology Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
| | - Budheswar Dehury
- Bioinformatics Division, ICMR-Regional Medical Research Centre, Bhubaneswar, India
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2
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Boral S, Sen S, Kushwaha T, Inampudi KK, De S. Extein residues regulate the catalytic function of Spl DnaX intein enzyme by restricting the near-attack conformations of the active-site residues. Protein Sci 2023; 32:e4699. [PMID: 37313648 PMCID: PMC10288555 DOI: 10.1002/pro.4699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 05/30/2023] [Accepted: 06/06/2023] [Indexed: 06/15/2023]
Abstract
Intein enzymes catalyze the splicing of their flanking polypeptide chains and have found tremendous biotechnological applications. Their terminal residues form the catalytic core and participate in the splicing reaction. Hence, the neighboring N- and C-terminal extein residues influence the catalytic rate. As these extein residues vary depending on the substrate identity, we tested the influence of 20 amino acids at these sites in the Spl DnaX intein and observed significant variation of spliced product as well as N- and C-terminus cleavage product formation. We investigated the dependence of these reactions on the extein residues by molecular dynamics (MD) simulations on eight extein variants, and found that the conformational sampling of the active-site residues of the intein enzyme differed among these extein variants. We found that the extein variants that sample higher population of near-attack conformers (NACs) of the active-site residues undergo higher product formation in our activity assays. Ground state conformers that closely resemble the transition state are referred to as NACs. Very good correlation was observed between the NAC populations from the MD simulations of eight extein variants and the corresponding product formation from our activity assays. Furthermore, this molecular detail enabled us to elucidate the mechanistic roles of several conserved active-site residues in the splicing reaction. Overall, this study shows that the catalytic power of Spl DnaX intein enzyme, and most likely other inteins, depends on the efficiency of formation of NACs in the ground state, which is further modulated by the extein residues.
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Affiliation(s)
- Soumendu Boral
- School of BioscienceIndian Institute of Technology KharagpurKharagpurIndia
| | - Srijon Sen
- School of BioscienceIndian Institute of Technology KharagpurKharagpurIndia
| | - Tushar Kushwaha
- Department of BiophysicsAll India Institute of Medical SciencesNew DelhiIndia
| | - Krishna K. Inampudi
- Department of BiophysicsAll India Institute of Medical SciencesNew DelhiIndia
| | - Soumya De
- School of BioscienceIndian Institute of Technology KharagpurKharagpurIndia
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3
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Voice AT, Tresadern G, Twidale RM, van Vlijmen H, Mulholland AJ. Mechanism of covalent binding of ibrutinib to Bruton's tyrosine kinase revealed by QM/MM calculations. Chem Sci 2021; 12:5511-5516. [PMID: 33995994 PMCID: PMC8097726 DOI: 10.1039/d0sc06122k] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Ibrutinib is the first covalent inhibitor of Bruton's tyrosine kinase (BTK) to be used in the treatment of B-cell cancers. Understanding the mechanism of covalent inhibition will aid in the design of safer and more selective covalent inhibitors that target BTK. The mechanism of covalent inhibition in BTK has been uncertain because there is no appropriate residue nearby that can act as a base to deprotonate the cysteine thiol prior to covalent bond formation. We investigate several mechanisms of covalent modification of C481 in BTK by ibrutinib using combined quantum mechanics/molecular mechanics (QM/MM) molecular dynamics reaction simulations. The lowest energy pathway involves direct proton transfer from C481 to the acrylamide warhead in ibrutinib, followed by covalent bond formation to form an enol intermediate. There is a subsequent rate-limiting keto-enol tautomerisation step (ΔG ‡ = 10.5 kcal mol-1) to reach the inactivated BTK/ibrutinib complex. Our results represent the first mechanistic study of BTK inactivation by ibrutinib to consider multiple mechanistic pathways. These findings should aid in the design of covalent drugs that target BTK and other similar targets.
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Affiliation(s)
- Angus T Voice
- Centre for Computational Chemistry, School of Chemistry, University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Gary Tresadern
- Computational Chemistry, Janssen Research & Development, Janssen Pharmaceutica N. V. Turnhoutseweg 30 B-2340 Beerse Belgium
| | - Rebecca M Twidale
- Centre for Computational Chemistry, School of Chemistry, University of Bristol Cantock's Close Bristol BS8 1TS UK
| | - Herman van Vlijmen
- Computational Chemistry, Janssen Research & Development, Janssen Pharmaceutica N. V. Turnhoutseweg 30 B-2340 Beerse Belgium
| | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol Cantock's Close Bristol BS8 1TS UK
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4
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Hassanzadeh P. Towards the quantum-enabled technologies for development of drugs or delivery systems. J Control Release 2020; 324:260-279. [DOI: 10.1016/j.jconrel.2020.04.050] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 04/28/2020] [Accepted: 04/29/2020] [Indexed: 12/20/2022]
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5
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Chen X, Chen HY, Chen ZD, Gong JN, Chen CYC. A novel artificial intelligence protocol for finding potential inhibitors of acute myeloid leukemia. J Mater Chem B 2020; 8:2063-2081. [PMID: 32068215 DOI: 10.1039/d0tb00061b] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
There is currently no effective treatment for acute myeloid leukemia, and surgery is also ineffective as an important treatment for most tumors. Rapidly developing artificial intelligence technology can be applied to different aspects of drug development, and it plays a key role in drug discovery. Based on network pharmacology and virtual screening, candidates were selected from the molecular database. Nine artificial intelligence algorithm models were used to further verify the candidates' potential. The 350 training results of the deep learning model showed higher credibility, and the R-square of the training set and test set of the optimal model reached 0.89 and 0.84, respectively. The random forest model has an R-square of 0.91 and a mean square error of only 0.003. The R-square of the Adaptive Boosting model and the Bagging model reached 0.92 and 0.88, respectively. Molecular dynamics simulation evaluated the stability of the ligand-protein complex and achieved good results. Artificial intelligence models had unearthed the promising candidates for STAT3 inhibitors, and the good performance of most models showed that they still had practical value on small data sets.
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Affiliation(s)
- Xu Chen
- Artificial Intelligence Medical Center, School of Intelligent Systems Engineering, Sun Yat-sen University, Shenzhen, 510275, China. and School of Pharmaceutical Sciences, Sun Yat-sen University, Shenzhen, 510275, China
| | - Hsin-Yi Chen
- Artificial Intelligence Medical Center, School of Intelligent Systems Engineering, Sun Yat-sen University, Shenzhen, 510275, China.
| | - Zhi-Dong Chen
- Artificial Intelligence Medical Center, School of Intelligent Systems Engineering, Sun Yat-sen University, Shenzhen, 510275, China. and School of Pharmaceutical Sciences, Sun Yat-sen University, Shenzhen, 510275, China
| | - Jia-Ning Gong
- Artificial Intelligence Medical Center, School of Intelligent Systems Engineering, Sun Yat-sen University, Shenzhen, 510275, China. and School of Pharmaceutical Sciences, Sun Yat-sen University, Shenzhen, 510275, China
| | - Calvin Yu-Chian Chen
- Artificial Intelligence Medical Center, School of Intelligent Systems Engineering, Sun Yat-sen University, Shenzhen, 510275, China. and Department of Medical Research, China Medical University Hospital, Taichung 40447, Taiwan and Department of Bioinformatics and Medical Engineering, Asia University, Taichung 41354, Taiwan
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6
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Ainsley J, Lodola A, Mulholland AJ, Christov CZ, Karabencheva-Christova TG. Combined Quantum Mechanics and Molecular Mechanics Studies of Enzymatic Reaction Mechanisms. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2018; 113:1-32. [PMID: 30149903 DOI: 10.1016/bs.apcsb.2018.07.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The combined quantum mechanics/molecular mechanics (QM/MM) methods have become a valuable tool in computational biochemistry and received versatile applications for studying the reaction mechanisms of enzymes. The approach combines the calculations of the electronic structure of the active site by QM, with modeling of the protein environment using MM force field, which allows the long-range electrostatics and steric effects on the enzyme reactivity to be accounted for. In this review, we review some key theoretical and computational aspects of the method and we also present some applications to particular enzymatic reactions such as tryptophan-7-halogenase, cyclooxygenase-1, and the epidermal growth factor receptor.
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Affiliation(s)
- Jon Ainsley
- Department of Applied Sciences, Faculty of Health and Life Sciences, Northumbria University, Newcastle upon Tyne, United Kingdom
| | | | - Adrian J Mulholland
- Centre for Computational Chemistry, School of Chemistry, University of Bristol, Bristol, United Kingdom
| | - Christo Z Christov
- Department of Chemistry, Michigan Technological University, Houghton, MI, United States.
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7
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Mujika JI, Lopez X. Unveiling the Catalytic Role of B-Block Histidine in the N–S Acyl Shift Step of Protein Splicing. J Phys Chem B 2017; 121:7786-7796. [DOI: 10.1021/acs.jpcb.7b04276] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. I. Mujika
- Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU) and Donostia International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi Spain
| | - X. Lopez
- Kimika Fakultatea, Euskal Herriko Unibertsitatea (UPV/EHU) and Donostia International Physics Center (DIPC), P.K. 1072, 20080 Donostia, Euskadi Spain
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8
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Ramsoomair CK, Yakely AE, Urbanski LM, Karanja K, Giaccone ZT, Siegart NM, Wang C, Gomez AV, Reitter JN, Mills KV. Coordination of the third step of protein splicing in two cyanobacterial inteins. FEBS Lett 2017. [PMID: 28649707 DOI: 10.1002/1873-3468.12730] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The third step of protein splicing is cyclization of Asn coupled to peptide bond cleavage. In two related cyanobacterial inteins, this step is facilitated by Asn or Gln. For a Synechococcus sp. PCC7002 intein, the isolated third step of protein splicing is more efficient with its native Asn than with substitution to Gln. For a Trichodesmium erythraeum intein, its native Gln facilitates the third step as efficiently as with Asn. Despite these differences, the yield of splicing is not affected, suggesting that the third step is influenced by mechanism-linked conformational changes. A conserved catalytic His and the penultimate residue also play roles in promoting side-chain cyclization.
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Affiliation(s)
| | - Anthony E Yakely
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Laura M Urbanski
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Kevin Karanja
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | | | - Nicolle M Siegart
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Chunyu Wang
- Department of Chemistry and Chemical Biology, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA.,Department of Biological Sciences, Center for Biotechnology and Interdisciplinary Studies, Rensselaer Polytechnic Institute, Troy, NY, USA
| | - Alvin V Gomez
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Julie N Reitter
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
| | - Kenneth V Mills
- Department of Chemistry, College of the Holy Cross, Worcester, MA, USA
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9
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Shi S, Chen H, Jiang H, Xie Y, Zhang L, Li N, Zhu C, Chen J, Luo H, Wang J, Feng L, Lu H, Zhu J. A novel self-cleavable tag Zbasic–∆I-CM and its application in the soluble expression of recombinant human interleukin-15 in Escherichia coli. Appl Microbiol Biotechnol 2016; 101:1133-1142. [DOI: 10.1007/s00253-016-7848-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2016] [Revised: 08/25/2016] [Accepted: 09/08/2016] [Indexed: 01/11/2023]
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10
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Capoferri L, Lodola A, Rivara S, Mor M. Quantum mechanics/molecular mechanics modeling of covalent addition between EGFR-cysteine 797 and N-(4-anilinoquinazolin-6-yl) acrylamide. J Chem Inf Model 2015; 55:589-99. [PMID: 25658136 DOI: 10.1021/ci500720e] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Irreversible epidermal growth factor receptor (EGFR) inhibitors can circumvent resistance to first-generation ATP-competitive inhibitors in the treatment of nonsmall-cell lung cancer. They covalently bind a noncatalytic cysteine (Cys797) at the surface of EGFR active site by an acrylamide warhead. Herein, we used a hybrid quantum mechanics/molecular mechanics (QM/MM) potential in combination with umbrella sampling in the path-collective variable space to investigate the mechanism of alkylation of Cys797 by the prototypical covalent inhibitor N-(4-anilinoquinazolin-6-yl) acrylamide. Calculations show that Cys797 reacts with the acrylamide group of the inhibitor through a direct addition mechanism, with Asp800 acting as a general base/general acid in distinct steps of the reaction. The obtained reaction free energy is negative (ΔA = -12 kcal/mol) consistent with the spontaneous and irreversible alkylation of Cys797 by N-(4-anilinoquinazolin-6-yl) acrylamide. Our calculations identify desolvation of Cys797 thiolate anion as a key step of the alkylation process, indicating that changes in the intrinsic reactivity of the acrylamide would have only a minor impact on the inhibitor potency.
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Affiliation(s)
- Luigi Capoferri
- Dipartimento di Farmacia, Università degli Studi di Parma, Viale delle Scienze 27/A, I-43124, Parma, Italy
| | - Alessio Lodola
- Dipartimento di Farmacia, Università degli Studi di Parma, Viale delle Scienze 27/A, I-43124, Parma, Italy
| | - Silvia Rivara
- Dipartimento di Farmacia, Università degli Studi di Parma, Viale delle Scienze 27/A, I-43124, Parma, Italy
| | - Marco Mor
- Dipartimento di Farmacia, Università degli Studi di Parma, Viale delle Scienze 27/A, I-43124, Parma, Italy
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11
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Cronin M, Coolbaugh MJ, Nellis D, Zhu J, Wood DW, Nussinov R, Ma B. Dynamics differentiate between active and inactive inteins. Eur J Med Chem 2015; 91:51-62. [PMID: 25087201 PMCID: PMC4308580 DOI: 10.1016/j.ejmech.2014.07.094] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 07/21/2014] [Accepted: 07/25/2014] [Indexed: 11/29/2022]
Abstract
The balance between stability and dynamics for active enzymes can be somewhat quantified by studies of intein splicing and cleaving reactions. Inteins catalyze the ligation of flanking host exteins while excising themselves. The potential for applications led to engineering of a mini-intein splicing domain, where the homing endonuclease domain of the Mycobacterium tuberculosis RecA (Mtu recA) intein was removed. The remaining domains were linked by several short peptides, but splicing activity in all was substantially lower than the full-length intein. Native splicing activity was restored in some cases by a V67L mutation. Using computations and experiments, we examine the impact of this mutation on the stability and conformational dynamics of the mini-intein splicing domain. Molecular dynamics simulations were used to delineate the factors that determine the active state, including the V67L mini-intein mutant, and peptide linker. We found that (1) the V67L mutation lowers the global fluctuations in all modeled mini-inteins, stabilizing the mini-intein constructs; (2) the connecting linker length affects intein dynamics; and (3) the flexibilities of the linker and intein core are higher in the active structure. We have observed that the interaction of the linker region and a turn region around residues 35-41 provides the pathway for the allostery interaction. Our experiments reveal that intein catalysis is characterized by non-linear Arrhenius plot, confirming the significant contribution of protein conformational dynamics to intein function. We conclude that while the V67L mutation stabilizes the global structure, cooperative dynamics of all intein regions appear more important for intein function than high stability. Our studies suggest that effectively quenching the conformational dynamics of an intein through engineered allosteric interactions could deactivate intein splicing or cleaving.
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Affiliation(s)
- Melissa Cronin
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA
| | - Michael J Coolbaugh
- Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, OH 43210, USA
| | - David Nellis
- Biopharmaceutical Development Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Jianwei Zhu
- School of Pharmacy, Shanghai Jiao Tong University, 800 DongChuan Road, Shanghai 200240, China
| | - David W Wood
- Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, OH 43210, USA
| | - Ruth Nussinov
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA; Sackler Inst. of Molecular Medicine, Department of Human Genetics and Molecular Medicine, Sackler School of Medicine, Tel Aviv University, Tel Aviv 69978, Israel
| | - Buyong Ma
- Basic Science Program, Leidos Biomedical Research, Inc., Cancer and Inflammation Program, National Cancer Institute, Frederick, MD 21702, USA.
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Comparative Analysis of the Effectiveness of C-terminal Cleavage Intein-Based Constructs in Producing a Recombinant Analog of Anophelin, an Anticoagulant from Anopheles albimanus. Appl Biochem Biotechnol 2014; 175:2468-88. [DOI: 10.1007/s12010-014-1400-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 11/12/2014] [Indexed: 11/27/2022]
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Abstract
Nicotinamidase (Pnc1) is a member of Zn-dependent amidohydrolases that hydrolyzes nicotinamide (NAM) to nicotinic acid (NA), which is a key step in the salvage pathway of NAD(+) biosynthesis. In this paper, the catalytic mechanism of Pnc1 has been investigated by using a combined quantum-mechanical/molecular-mechanical (QM/MM) approach based on the recently obtained crystal structure of Pnc1. The reaction pathway, the detail of each elementary step, the energetics of the whole catalytic cycle, and the roles of key residues and Zn-binding site are illuminated. Our calculation results indicate that the catalytic water molecule comes from the bulk solvent, which is then deprotonated by residue D8. D8 functions as a proton transfer station between C167 and NAM, while the activated C167 serves as the nucleophile. The residue K122 only plays a role in stabilizing intermediates and transition states. The oxyanion hole formed by the amide backbone nitrogen atoms of A163 and C167 has the function to stabilize the hydroxyl anion of nicotinamide. The Zn-binding site rather than a single Zn(2+) ion acts as a Lewis acid to influence the reaction. Two elementary steps, the activation of C167 in the deamination process and the decomposition of catalytic water in the hydrolysis process, correspond to the large energy barriers of 25.7 and 28.1 kcal mol(-1), respectively, meaning that both of them contribute a lot to the overall reaction barrier. Our results may provide useful information for the design of novel and efficient Pnc1 inhibitors and related biocatalytic applications.
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Affiliation(s)
- Xiang Sheng
- School of Chemistry and Chemical Engineering, Shandong University, Jinan, Shandong 250100, China
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Abstract
The first crystal trans-structure of a naturally occurring split intein has been determined for the Npu (Nostoc punctiforme PCC73102) DnaE split intein. Guided by this structure, the residues NArg50 and CSer35, well conserved in DnaE split inteins, are identified to be critical in the trans-splicing of Npu DnaE split intein. An in vitro splicing assay demonstrates that NArg50 and CSer35 play synergistic roles in modulating its intein activity. The C-terminal CAsn36 exhibits two orientations of its side chain and interacts with both NArg50 and CSer35 through hydrogen bonding. These interactions likely facilitate the cyclization of asparagine in the course of protein splicing. The mutation of either residue reduces intein activity, and correlates with the low activity of the Ssp (Cyanobacterium synechocystis sp. strain PCC6803) DnaE split intein. On the other hand, NArg50 also forms a hydrogen bond with the highly conserved F-block CAsp17, thus influencing the N-S acyl shift during N-terminal cleavage. Sequence alignments show that residues NArg50 and CSer35 are rather conserved in those split inteins that lack a penultimate histidine residue. The conserved non-catalytic residues of split inteins modulate the efficiency of protein trans-splicing by hydrogen-bond interactions with the catalytic residues at the splice junction.
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15
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Jitonnom J, Limb MAL, Mulholland AJ. QM/MM free-energy simulations of reaction in Serratia marcescens Chitinase B reveal the protonation state of Asp142 and the critical role of Tyr214. J Phys Chem B 2014; 118:4771-83. [PMID: 24730355 DOI: 10.1021/jp500652x] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Serratia marcescens Chitinase B (ChiB), belonging to the glycosidase family 18 (GH18), catalyzes the hydrolysis of β-1,4-glycosidic bond, with retention of configuration, via an unusual substrate-assisted mechanism, in which the substrate itself acts as an intramolecular nucleophile. Here, both elementary steps (glycosylation and deglycosylation) of the ChiB-catalyzed reaction are investigated by means of combined quantum mechanics/molecular mechanics (QM/MM) umbrella sampling molecular dynamics (MD) simulations at the SCC-DFTB/CHARMM22 level of theory. We examine the influence of the Asp142 protonation state on the reaction and the role that this residue performs in the reaction. Our simulations show that reaction with a neutral Asp142 is preferred and demonstrate that this residue provides electrostatic stabilization of the oxazolinium ion intermediate formed in the reaction. Insight into the conformational itinerary ((1,4)B↔(4)H5↔(4)C1) adopted by the substrate (bound in subsite -1) along the preferred reaction pathway is also provided by the simulations. The relative energies of the stationary points found along the reaction pathway calculated with SCC-DFTB and B3LYP were compared. The results suggest that SCC-DFTB is an accurate method for estimating the relative barriers for both steps of the reaction; however, it was found to overestimate the relative energy of an intermediate formed in the reaction when compared with the higher level of theory. Glycosylation is suggested to be a rate-determining step in the reaction with calculated overall reaction free-energy barrier of 20.5 kcal/mol, in a reasonable agreement with the 16.1 kcal/mol barrier derived from the experiment. The role of Tyr214 in catalysis was also investigated with the results, indicating that the residue plays a critical role in the deglycosylation step of the reaction. Simulations of the enzyme-product complex were also performed with an unbinding event suggested to have been observed, affording potential new mechanistic insight into the release of the product of ChiB.
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Affiliation(s)
- Jitrayut Jitonnom
- Division of Chemistry, School of Science, University of Phayao , Phayao 56000, Thailand
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16
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Abstract
Inteins are nature's escape artists; they facilitate their excision from flanking polypeptides (exteins) concomitant with extein ligation to produce a mature host protein. Splicing requires sequential nucleophilic displacement reactions catalyzed by strategies similar to proteases and asparagine lyases. Inteins require precise reaction coordination rather than rapid turnover or tight substrate binding because they are single turnover enzymes with covalently linked substrates. This has allowed inteins to explore alternative mechanisms with different steps or to use different methods for activation and coordination of the steps. Pressing issues include understanding the underlying details of catalysis and how the splicing steps are controlled.
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Affiliation(s)
- Kenneth V Mills
- From the Department of Chemistry, College of the Holy Cross, Worcester, Massachusetts 01610
| | - Margaret A Johnson
- the Department of Chemistry, University of Alabama at Birmingham, Birmingham, Alabama 35294, and
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17
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Basu A, Mishra B, Dey S, Leong SSJ. Intein based bioprocess for production of a synthetic antimicrobial peptide: an alternative route to solid phase peptide synthesis. RSC Adv 2014. [DOI: 10.1039/c4ra04056b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Intein based bioprocessing strategy for producing antimicrobial peptide candidate was found to be more sustainable compared to solid phase peptide synthesis strategy (SPPS).
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Affiliation(s)
- Anindya Basu
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- , Singapore
| | - Biswajit Mishra
- School of Chemical and Biomedical Engineering
- Nanyang Technological University
- , Singapore
| | - Sharmistha Dey
- Department of Biophysics
- All India Institute of Medical Sciences
- New Delhi, India
| | - Susanna Su Jan Leong
- Singapore Institute of Technology
- , Singapore
- Department of Biochemistry
- Yong Loo Lin School of Medicine
- National University of Singapore
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Enhanced Sampling in Molecular Dynamics Using Metadynamics, Replica-Exchange, and Temperature-Acceleration. ENTROPY 2013. [DOI: 10.3390/e16010163] [Citation(s) in RCA: 282] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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19
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Hoffmann T, Müller S, Nadmid S, Garcia R, Müller R. Microsclerodermins from Terrestrial Myxobacteria: An Intriguing Biosynthesis Likely Connected to a Sponge Symbiont. J Am Chem Soc 2013; 135:16904-11. [DOI: 10.1021/ja4054509] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Affiliation(s)
- Thomas Hoffmann
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz
Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Building C 2.3, D-66123 Saarbrücken, Germany
| | - Stefan Müller
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz
Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Building C 2.3, D-66123 Saarbrücken, Germany
| | - Suvd Nadmid
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz
Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Building C 2.3, D-66123 Saarbrücken, Germany
| | - Ronald Garcia
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz
Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Building C 2.3, D-66123 Saarbrücken, Germany
| | - Rolf Müller
- Helmholtz Institute for Pharmaceutical Research Saarland, Helmholtz
Centre for Infection Research and Department of Pharmaceutical Biotechnology, Saarland University, Building C 2.3, D-66123 Saarbrücken, Germany
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Duarte F, Amrein BA, Kamerlin SCL. Modeling catalytic promiscuity in the alkaline phosphatase superfamily. Phys Chem Chem Phys 2013; 15:11160-77. [PMID: 23728154 PMCID: PMC3693508 DOI: 10.1039/c3cp51179k] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2013] [Accepted: 05/02/2013] [Indexed: 12/19/2022]
Abstract
In recent years, it has become increasingly clear that promiscuity plays a key role in the evolution of new enzyme function. This finding has helped to elucidate fundamental aspects of molecular evolution. While there has been extensive experimental work on enzyme promiscuity, computational modeling of the chemical details of such promiscuity has traditionally fallen behind the advances in experimental studies, not least due to the nearly prohibitive computational cost involved in examining multiple substrates with multiple potential mechanisms and binding modes in atomic detail with a reasonable degree of accuracy. However, recent advances in both computational methodologies and power have allowed us to reach a stage in the field where we can start to overcome this problem, and molecular simulations can now provide accurate and efficient descriptions of complex biological systems with substantially less computational cost. This has led to significant advances in our understanding of enzyme function and evolution in a broader sense. Here, we will discuss currently available computational approaches that can allow us to probe the underlying molecular basis for enzyme specificity and selectivity, discussing the inherent strengths and weaknesses of each approach. As a case study, we will discuss recent computational work on different members of the alkaline phosphatase superfamily (AP) using a range of different approaches, showing the complementary insights they have provided. We have selected this particular superfamily, as it poses a number of significant challenges for theory, ranging from the complexity of the actual reaction mechanisms involved to the reliable modeling of the catalytic metal centers, as well as the very large system sizes. We will demonstrate that, through current advances in methodologies, computational tools can provide significant insight into the molecular basis for catalytic promiscuity, and, therefore, in turn, the mechanisms of protein functional evolution.
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Affiliation(s)
- Fernanda Duarte
- Uppsala University, Science for Life Laboratory (SciLifeLab), Cell and Molecular Biology, Uppsala, Sweden. ; ;
| | - Beat Anton Amrein
- Uppsala University, Science for Life Laboratory (SciLifeLab), Cell and Molecular Biology, Uppsala, Sweden. ; ;
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21
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Lodola A, Capoferri L, Rivara S, Tarzia G, Piomelli D, Mulholland A, Mor M. Quantum mechanics/molecular mechanics modeling of fatty acid amide hydrolase reactivation distinguishes substrate from irreversible covalent inhibitors. J Med Chem 2013; 56:2500-12. [PMID: 23425199 DOI: 10.1021/jm301867x] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Carbamate and urea derivatives are important classes of fatty acid amide hydrolase (FAAH) inhibitors that carbamoylate the active-site nucleophile Ser241. In the present work, the reactivation mechanism of carbamoylated FAAH is investigated by means of a quantum mechanics/molecular mechanics (QM/MM) approach. The potential energy surfaces for decarbamoylation of FAAH covalent adducts, derived from the O-aryl carbamate URB597 and from the N-piperazinylurea JNJ1661610, were calculated and compared to that for deacylation of FAAH acylated by the substrate oleamide. Calculations show that a carbamic group bound to Ser241 prevents efficient stabilization of transition states of hydrolysis, leading to large increments in the activation barrier. Moreover, the energy barrier for the piperazine carboxylate was significantly lower than that for the cyclohexyl carbamate derived from URB597. This is consistent with experimental data showing slowly reversible FAAH inhibition for the N-piperazinylurea inhibitor and irreversible inhibition for URB597.
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Affiliation(s)
- Alessio Lodola
- Dipartimento di Farmacia, Università degli Studi di Parma, I-43124 Parma, Italy
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22
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Roca M, Aranda J, Moliner V, Tuñón I. Modeling methods for studying post-translational and transcriptional modifying enzymes. Curr Opin Chem Biol 2012; 16:465-71. [PMID: 23127358 DOI: 10.1016/j.cbpa.2012.10.014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Revised: 09/20/2012] [Accepted: 10/11/2012] [Indexed: 10/27/2022]
Abstract
Biological catalysis is a complex chemical process that involves not only electronic reorganization in the substrate but also the reorganization of the catalyst. This complexity is even larger in the case of post-transcriptional and post-translational modifications which may involve the interaction between two biomacromolecules. However, the development over the past decades of new computational methods and strategies is offering a detailed molecular picture of the catalytic event and a deep understanding of the mechanisms of chemical reactions in biological environments. Here we review the efforts made in the last years to model catalysis in post-transcriptional and post-translational processes. We stress on the advantages and problems of the different computational strategies and their applicability in different cases.
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Affiliation(s)
- Maite Roca
- Departamento de Química Física, Universitat de València, 46100 Burjassot, Spain
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23
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Wang S, Orabi EA, Baday S, Bernèche S, Lamoureux G. Ammonium Transporters Achieve Charge Transfer by Fragmenting Their Substrate. J Am Chem Soc 2012; 134:10419-27. [DOI: 10.1021/ja300129x] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Shihao Wang
- Department of Chemistry and
Biochemistry and Centre for Research in Molecular Modeling (CERMM), Concordia University, 7141 Sherbrooke Street West,
Montréal, Québec H4B 1R6, Canada
| | - Esam A. Orabi
- Department of Chemistry and
Biochemistry and Centre for Research in Molecular Modeling (CERMM), Concordia University, 7141 Sherbrooke Street West,
Montréal, Québec H4B 1R6, Canada
| | - Sefer Baday
- Swiss Institute of Bioinformatics
and Biozentrum, University of Basel, Klingelbergstrasse
50/70, CH-4056 Basel, Switzerland
| | - Simon Bernèche
- Swiss Institute of Bioinformatics
and Biozentrum, University of Basel, Klingelbergstrasse
50/70, CH-4056 Basel, Switzerland
| | - Guillaume Lamoureux
- Department of Chemistry and
Biochemistry and Centre for Research in Molecular Modeling (CERMM), Concordia University, 7141 Sherbrooke Street West,
Montréal, Québec H4B 1R6, Canada
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24
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Wallin G, Härd T, Åqvist J. Folding-Reaction Coupling in a Self-Cleaving Protein. J Chem Theory Comput 2012; 8:3871-9. [DOI: 10.1021/ct3001427] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Göran Wallin
- Department of Cell and Molecular
Biology, Uppsala University, Box 596, SE-751 24 Uppsala, Sweden
| | - Torleif Härd
- Department of Molecular Biology,
Swedish University of Agricultural Sciences (SLU), Box 590, SE-751
24 Uppsala, Sweden
| | - Johan Åqvist
- Department of Cell and Molecular
Biology, Uppsala University, Box 596, SE-751 24 Uppsala, Sweden
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25
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Insights into conformational changes of procarboxypeptidase A and B from simulations: a plausible explanation for different intrinsic activity. Theor Chem Acc 2012. [DOI: 10.1007/s00214-012-1224-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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