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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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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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Hong B, Haddad M, Maley F, Jensen JH, Kohen A. Hydride transfer versus hydrogen radical transfer in thymidylate synthase. J Am Chem Soc 2007; 128:5636-7. [PMID: 16637621 PMCID: PMC3253763 DOI: 10.1021/ja060196o] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The nature of a H-transfer in the thymidylate synthase catalyzed reaction was investigated by comparison of the wild-type enzyme with the W80M mutant. The nature of the H-transfer was not affected, as indicated by intrinsic isotope effects and their temperature dependence. These findings support a single-step hydride transfer instead of a two-step radical transfer.
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Affiliation(s)
- Baoyu Hong
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242-1294
| | - Majd Haddad
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242-1294
| | - Frank Maley
- Wadsworth Center, New York State Dept. Of Health Empire State Plaza, Albany, NY 12201-0509
| | - Jan H. Jensen
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242-1294
| | - Amnon Kohen
- Department of Chemistry, University of Iowa, Iowa City, IA, 52242-1294
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Kuiper GGJM, Klootwijk W, Visser TJ. Substitution of cysteine for a conserved alanine residue in the catalytic center of type II iodothyronine deiodinase alters interaction with reducing cofactor. Endocrinology 2002; 143:1190-8. [PMID: 11897672 DOI: 10.1210/endo.143.4.8738] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
UNLABELLED Human type II iodothyronine deiodinase (D2) catalyzes the activation of T(4) to T(3). The D2 enzyme, like the type I (D1) and type III (D3) deiodinases, contains a selenocysteine (SeC) residue (residue 133 in D2) in the highly conserved catalytic center. Remarkably, all of the D2 proteins cloned so far have an alanine two residue-amino terminal to the SeC, whereas all D1 and D3 proteins contain a cysteine at this position. A cysteine residue in the catalytic center could assist in enzymatic action by providing a nucleophilic sulfide or by participating in redox reactions with a cofactor or enzyme residues. We have investigated whether D2 mutants with a cysteine (A131C) or serine (A131S) two-residue amino terminal to the SeC are enzymatically active and have characterized these mutants with regard to substrate affinity, reducing cofactor interaction and inhibitor profile. COS cells were transfected with expression vectors encoding wild-type (wt) D2, D2 A131C, or D2 A131S proteins. Kinetic analysis was performed on homogenates with dithiothreitol (DTT) as reducing cofactor. The D2 A131C and A131S mutants displayed similar Michaelis-Menten constant values for T(4) (5 nM) and reverse T(3) (9 nM) as the wt D2 enzyme. The limiting Michaelis-Menten constant for DTT of the D2 A131C enzyme was 3-fold lower than that of the wt D2 enzyme. The wt and mutant D2 enzymes are essentially insensitive to propylthiouracil [concentration inhibiting 50% of activity (IC(50)) > 2 mM] in the presence of 20 mM DTT, but when tested in the presence of 0.2 mM DTT the IC(50) value for propylthiouracil is reduced to about 0.1 mM. During incubations of intact COS cells expressing wt D2, D2 A131C, or D2 A131S, addition of increasing amounts of unlabeled T(4) resulted in the saturation of [(125)I]T(4) deiodination, as reflected in a decrease of [(125)I]T(3) release into the medium. Saturation first appeared at medium T(4) concentrations between 1 and 10 nM. IN CONCLUSION substitution of cysteine for a conserved alanine residue in the catalytic center of the D2 protein does not inactivate the enzyme in vitro and in situ, but rather improves the interaction with the reducing cofactor DTT in vitro.
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Affiliation(s)
- George G J M Kuiper
- Department of Internal Medicine, Erasmus University Medical Center, 3000 DR Rotterdam, The Netherlands
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Barrett JE, Maltby DA, Santi DV, Schultz PG. Trapping of the C5 Methylene Intermediate in Thymidylate Synthase. J Am Chem Soc 1998. [DOI: 10.1021/ja973210t] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- J. E. Barrett
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 Departments of Pharmaceutical Chemistry and Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
| | - D. A. Maltby
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 Departments of Pharmaceutical Chemistry and Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
| | - D. V. Santi
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 Departments of Pharmaceutical Chemistry and Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
| | - P. G. Schultz
- Department of Chemistry, University of California at Berkeley, Berkeley, California 94720 Departments of Pharmaceutical Chemistry and Biochemistry and Biophysics, University of California at San Francisco, San Francisco, California 94143
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Abstract
Thymidylate synthase (TS) is a very interesting target in antiproliferative diseases. Its inhibition causes thimineless death of the cells and compounds inhibiting TS are widely used in anticancer therapy. The classical antifolate TS inhibitors are structural analogs of the folate cofactor; they often share the same metabolic pathways and this causes the development of resistance inside the cells. A detailed analysis of the available x-ray crystal structures of the complexes of the enzyme with different substrates and inhibitors support the finding of a structural basis of their biological activity. TS inhibitors nonstructural analog of folate, non-analog antifolate inhibitors (NAAI), are welcome as a new interesting research topic. Among the most recent and interesting ones, compounds from Agouron related to the indole structure, are independent on the folate metabolism, highly active and specific for human TS. Other compounds, phthalein derivatives, can inhibit TS enzymes from various sources and show an interesting biological activity profile: they inhibit better bacterial and fungal TS than human TS. The x-ray crystal structures of some of these inhibitors with TS show that they bind in a different binding site from that of the classical folate TS inhibitors. This indicates a potential allosteric binding site useful for future drug discovery studies.
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Affiliation(s)
- M P Costi
- Dipartimento di Scienze Farmaceutiche, Universitá di Modena, Italy
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