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Prokopowicz M, Jarmuła A, Casamayou-Boucau Y, Gordon F, Ryder A, Sobich J, Maj P, Cieśla J, Zieliński Z, Fita P, Rode W. Advanced Spectroscopy and APBS Modeling for Determination of the Role of His190 and Trp103 in Mouse Thymidylate Synthase Interaction with Selected dUMP Analogues. Int J Mol Sci 2021; 22:2661. [PMID: 33800923 PMCID: PMC7962005 DOI: 10.3390/ijms22052661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 02/26/2021] [Accepted: 03/02/2021] [Indexed: 11/18/2022] Open
Abstract
A homo-dimeric enzyme, thymidylate synthase (TS), has been a long-standing molecular target in chemotherapy. To further elucidate properties and interactions with ligands of wild-type mouse thymidylate synthase (mTS) and its two single mutants, H190A and W103G, spectroscopic and theoretical investigations have been employed. In these mutants, histidine at position 190 and tryptophan at position 103 are substituted with alanine and glycine, respectively. Several emission-based spectroscopy methods used in the paper demonstrate an especially important role for Trp 103 in TS ligands binding. In addition, the Advanced Poisson-Boltzmann Solver (APBS) results show considerable differences in the distribution of electrostatic potential around Trp 103, as compared to distributions observed for all remaining Trp residues in the mTS family of structures. Together, spectroscopic and APBS results reveal a possible interplay between Trp 103 and His190, which contributes to a reduction in enzymatic activity in the case of H190A mutation. Comparison of electrostatic potential for mTS complexes, and their mutants, with the substrate, dUMP, and inhibitors, FdUMP and N4-OH-dCMP, suggests its weaker influence on the enzyme-ligand interactions in N4OH-dCMP-mTS compared to dUMP-mTS and FdUMP-mTS complexes. This difference may be crucial for the explanation of the "abortive reaction" inhibitory mechanism of N4OH-dCMP towards TS. In addition, based on structural analyses and the H190A mutant capacity to form a denaturation-resistant complex with N4-OH-dCMP in the mTHF-dependent reaction, His190 is apparently responsible for a strong preference of the enzyme active center for the anti rotamer of the imino inhibitor form.
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Affiliation(s)
- Małgorzata Prokopowicz
- Inter-Faculty Interdisciplinary Doctoral Studies in Natural Sciences and Mathematics, MISMaP College, University of Warsaw, ul. Banacha 2C, 02-097 Warsaw, Poland
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland;
- Nencki Institute of Experimental Biology, ul. Pasteura 3, 02-093 Warsaw, Poland; (A.J.); (J.S.); (P.M.); (Z.Z.)
| | - Adam Jarmuła
- Nencki Institute of Experimental Biology, ul. Pasteura 3, 02-093 Warsaw, Poland; (A.J.); (J.S.); (P.M.); (Z.Z.)
| | - Yannick Casamayou-Boucau
- Nanoscale BioPhotonics Laboratory, School of Chemistry, National University of Ireland, University Road, H91 TK33 Galway, Ireland; (Y.C.-B.); (F.G.); (A.R.)
| | - Fiona Gordon
- Nanoscale BioPhotonics Laboratory, School of Chemistry, National University of Ireland, University Road, H91 TK33 Galway, Ireland; (Y.C.-B.); (F.G.); (A.R.)
| | - Alan Ryder
- Nanoscale BioPhotonics Laboratory, School of Chemistry, National University of Ireland, University Road, H91 TK33 Galway, Ireland; (Y.C.-B.); (F.G.); (A.R.)
| | - Justyna Sobich
- Nencki Institute of Experimental Biology, ul. Pasteura 3, 02-093 Warsaw, Poland; (A.J.); (J.S.); (P.M.); (Z.Z.)
| | - Piotr Maj
- Nencki Institute of Experimental Biology, ul. Pasteura 3, 02-093 Warsaw, Poland; (A.J.); (J.S.); (P.M.); (Z.Z.)
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, UK
| | - Joanna Cieśla
- Faculty of Chemistry, Warsaw University of Technology, ul Noakowskiego 3, 00-664 Warsaw, Poland;
| | - Zbigniew Zieliński
- Nencki Institute of Experimental Biology, ul. Pasteura 3, 02-093 Warsaw, Poland; (A.J.); (J.S.); (P.M.); (Z.Z.)
| | - Piotr Fita
- Institute of Experimental Physics, Faculty of Physics, University of Warsaw, ul. Pasteura 5, 02-093 Warsaw, Poland;
| | - Wojciech Rode
- Nencki Institute of Experimental Biology, ul. Pasteura 3, 02-093 Warsaw, Poland; (A.J.); (J.S.); (P.M.); (Z.Z.)
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Landau MJ, Sharma H, Anderson KS. Selective peptide inhibitors of bifunctional thymidylate synthase-dihydrofolate reductase from Toxoplasma gondii provide insights into domain-domain communication and allosteric regulation. Protein Sci 2013; 22:1161-73. [PMID: 23813474 DOI: 10.1002/pro.2300] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2013] [Revised: 06/14/2013] [Accepted: 06/17/2013] [Indexed: 11/05/2022]
Abstract
The bifunctional enzyme thymidylate synthase-dihydrofolate reductase (TS-DHFR) plays an essential role in DNA synthesis and is unique to several species of pathogenic protozoans, including the parasite Toxoplasma gondii. Infection by T. gondii causes the prevalent disease toxoplasmosis, for which TS-DHFR is a major therapeutic target. Here, we design peptides that target the dimer interface between the TS domains of bifunctional T. gondii TS-DHFR by mimicking β-strands at the interface, revealing a previously unknown allosteric target. The current study shows that these β-strand mimetic peptides bind to the apo-enzyme in a species-selective manner to inhibit both the TS and distal DHFR. Fluorescence spectroscopy was used to monitor conformational switching of the TS domain and demonstrate that these peptides induce a conformational change in the enzyme. Using structure-guided mutagenesis, nonconserved residues in the linker between TS and DHFR were identified that play a key role in domain-domain communication and in peptide inhibition of the DHFR domain. These studies validate allosteric inhibition of apo-TS, specifically at the TS-TS interface, as a potential target for novel, species-specific therapeutics for treating T. gondii parasitic infections and overcoming drug resistance.
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Affiliation(s)
- Mark J Landau
- Department of Pharmacology, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut, 06510; Department of Molecular Biophysics and Biochemistry, Yale University School of Medicine, 333 Cedar Street, New Haven, Connecticut, 06510
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Arvizu-Flores AA, Aispuro-Hernandez E, Garcia-Orozco KD, Varela-Romero A, Valenzuela-Soto E, Velazquez-Contreras EF, Rojo-Domínguez A, Yepiz-Plascencia G, Maley F, Sotelo-Mundo RR. Functional identity of the active sites of crustacean and viral thymidylate synthases. Comp Biochem Physiol C Toxicol Pharmacol 2009; 150:406-13. [PMID: 19559812 DOI: 10.1016/j.cbpc.2009.06.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2009] [Revised: 06/15/2009] [Accepted: 06/16/2009] [Indexed: 12/01/2022]
Abstract
Thymidylate synthase (TS) catalyzes the synthesis of deoxythymidine monophosphate (dTMP), which is an essential precursor for DNA synthesis. The rationale underlying drug design is to identify compounds that differentially inhibit a viral or parasite enzyme vs. the host homologue. We studied the TS of the white spot syndrome virus (WSSV TS) and the corresponding TS from the host, the marine invertebrate shrimp Litopenaeus vannamei. TS is the only de novo source of dTMP and is essential for host and viral DNA replication. To establish proof of principle, we cloned a full-length TS cDNA from the white shrimp L. vannamei (shrimp TS) that corresponds to a deduced sequence of 289 amino acids and over-expressed it to study inhibition of both shrimp and viral TSs. Steady-state kinetic parameters for both TSs are similar, and dissociation (K(d)) or half maximal inhibitory concentration constants (IC(50)) did not show differential inhibition between the folate analogues. Differences in their amino acid sequence are not reflected in theoretical molecular models of both TSs, since both appear to have identical active sites. These results suggest that the eukaryotic TS active site is very constrained into the functional residues involved in reductive methylation of 2'-deoxyuridine-5'-monophosphate (dUMP).
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Affiliation(s)
- Aldo A Arvizu-Flores
- Centro de Investigación en Alimentación y Desarrollo (CIAD), Hermosillo, Sonora, Mexico
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Arvizu-Flores AA, Sugich-Miranda R, Arreola R, Garcia-Orozco KD, Velazquez-Contreras EF, Montfort WR, Maley F, Sotelo-Mundo RR. Role of an invariant lysine residue in folate binding on Escherichia coli thymidylate synthase: calorimetric and crystallographic analysis of the K48Q mutant. Int J Biochem Cell Biol 2008; 40:2206-17. [PMID: 18403248 PMCID: PMC2533807 DOI: 10.1016/j.biocel.2008.02.025] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2007] [Revised: 02/20/2008] [Accepted: 02/27/2008] [Indexed: 11/25/2022]
Abstract
Thymidylate synthase (TS) catalyzes the reductive methylation of deoxyuridine monophosphate (dUMP) using methylene tetrahydrofolate (CH(2)THF) as cofactor, the glutamate tail of which forms a water-mediated hydrogen bond with an invariant lysine residue of this enzyme. To understand the role of this interaction, we studied the K48Q mutant of Escherichia coli TS using structural and biophysical methods. The k(cat) of the K48Q mutant was 430-fold lower than wild-type TS in activity, while the K(m) for the (R)-stereoisomer of CH(2)THF was 300 microM, about 30-fold larger than K(m) from the wild-type TS. Affinity constants were determined using isothermal titration calorimetry, which showed that binding was reduced by one order of magnitude for folate-like TS inhibitors, such as propargyl-dideazafolate (PDDF) or compounds that distort the TS active site like BW1843U89 (U89). The crystal structure of the K48Q-dUMP complex revealed that dUMP binding is not impaired in the mutant, and that U89 in a ternary complex of K48Q-nucleotide-U89 was bound in the active site with subtle differences relative to comparable wild-type complexes. PDDF failed to form ternary complexes with K48Q and dUMP. Thermodynamic data correlated with the structural determinations, since PDDF binding was dominated by enthalpic effects while U89 had an important entropic component. In conclusion, K48 is critical for catalysis since it leads to a productive CH(2)THF binding, while mutation at this residue does not affect much the binding of inhibitors that do not make contact with this group.
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Affiliation(s)
- Aldo A. Arvizu-Flores
- Aquatic Molecular Biology Laboratory, Centro de Investigación en Alimentación y Desarrollo, A.C. Hermosillo, Sonora, México 83000
| | - Rocio Sugich-Miranda
- Departamento de Investigación en Polímeros y Materiales, Universidad de Sonora, Hermosillo, Sonora, México
| | - Rodrigo Arreola
- Departamento de Bioquímica, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, México DF 04510
| | - Karina D. Garcia-Orozco
- Aquatic Molecular Biology Laboratory, Centro de Investigación en Alimentación y Desarrollo, A.C. Hermosillo, Sonora, México 83000
| | | | - William R. Montfort
- Department of Biochemistry and Molecular Biophysics, The University of Arizona, Tucson, Arizona 85721, USA
| | - Frank Maley
- Wadsworth Center, New York State Department of Health, Albany, New York, 12201, USA
| | - Rogerio R. Sotelo-Mundo
- Aquatic Molecular Biology Laboratory, Centro de Investigación en Alimentación y Desarrollo, A.C. Hermosillo, Sonora, México 83000
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Lovelace LL, Gibson LM, Lebioda L. Cooperative inhibition of human thymidylate synthase by mixtures of active site binding and allosteric inhibitors. Biochemistry 2007; 46:2823-30. [PMID: 17297914 PMCID: PMC2516748 DOI: 10.1021/bi061309j] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Thymidylate synthase (TS) is a target in the chemotherapy of colorectal cancer and some other neoplasms. It catalyzes the transfer of a methyl group from methylenetetrahydrofolate to dUMP to form dTMP. On the basis of structural considerations, we have introduced 1,3-propanediphosphonic acid (PDPA) as an allosteric inhibitor of human TS (hTS); it is proposed that PDPA acts by stabilizing an inactive conformer of loop 181-197. Kinetic studies showed that PDPA is a mixed (noncompetitive) inhibitor versus dUMP. In contrast, versus methylenetrahydrofolate at concentrations lower than 0.25 microM, PDPA is an uncompetitive inhibitor, while at PDPA concentrations higher than 1 microM the inhibiton is noncompetive, as expected. At the concentrations corresponding to uncompetitive inhibition, PDPA shows positive cooperativity with an antifolate inhibitor, ZD9331, which binds to the active conformer. PDPA binding leads to the formation of hTS tetramers, but not higher oligomers. These data are consistent with a model in which hTS exists preferably as an asymmetric dimer with one subunit in the active conformation of loop 181-197 and the other in the inactive conformation.
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Affiliation(s)
- Leslie L. Lovelace
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Lydia M. Gibson
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
| | - Lukasz Lebioda
- Department of Chemistry and Biochemistry, University of South Carolina, Columbia, South Carolina 29208
- Center for Colon Cancer Research, University of South Carolina, Columbia, South Carolina 29208
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Jarmuła A, Cieplak P, Leś A, Rode W. Relative free energies of binding to thymidylate synthase of 2- and/or 4-thio and/or 5-fluoro analogues of dUMP. J Comput Aided Mol Des 2004; 17:699-710. [PMID: 15068368 DOI: 10.1023/b:jcam.0000017377.07094.2e] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Free energy perturbation calculations have been applied to evaluate the relative free energies of binding of 2'-deoxyuridine-5'-monophosphate (dUMP) and its 2- and/or 4-thio and/or 5-fluoro analogues to the wild-type E. coli thymidylate synthase (ecTS). The results accurately reproduce experimentally measured differences in the free energy of binding of dUMP versus 5-fluoro-dUMP to thymidylate synthase. They indicate that preferred binding of dUMP compared to 5-fluoro-dUMP in the binary complex is equally related to (i) more favorable electrostatic interactions of the dUMP molecule in the enzyme active site, and (ii) its less favorable solvation in the aqueous solution. The relative free energies of binding in the binary complex show moderate and qualitatively indistinguishable discrimination among the studied fluorinated and non-fluorinated 2- and/or 4-thio analogues of dUMP. The binding free energies of monothio analogues of dUMP and 5-fluoro-dUMP correspond quite well with experimentally measured activities of these nucleotides in the thymidylate synthase reaction. On the other hand, the binding free energies of both dithio analogues, 2,4-dithio-dUMP and 2,4-dithio-FdUMP, show lack of such correlation. The latter suggests that very low activities of the dithio analogues of dUMP and 5-fluoro-dUMP may relate more to the covalent reaction of these nucleotides within the ternary complex with TS and 5,10-methylenetetrahydrofolate, than to their pre-covalent binding. We speculate that a lack of substrate activity of 2,4-dithio-dUMP is related to the high aromaticity of its pyrimidine ring that prevents the Michael addition of the active site cysteine thiol to the pyrimidine C6 atom. A stronger affinity of the fluorinated analogues of dUMP to thymidylate synthase, compared to the non-fluorinated congeners, results from the fluorine substituent producing a local strain in the C6 region in the pyrimidine ring, thus sensitizing C6 to the Michael addition of the cysteine thiol.
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Affiliation(s)
- Adam Jarmuła
- Nencki Institute of Experimental Biology, Polish Academy of Sciences, 3 Pasteur St., 02-093 Warszawa, Poland.
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Ackland SP, Beale P, Peters GJ. Thymidylate synthase inhibitors. CANCER CHEMOTHERAPY AND BIOLOGICAL RESPONSE MODIFIERS 2003; 21:1-28. [PMID: 15338738 DOI: 10.1016/s0921-4410(03)21001-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Stephen P Ackland
- Department of Medical Oncology, Newcastle Mater Misericordiae Hospital, NSW, Australia.
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