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Domínguez-Pérez I, Téllez-Sanz R, Leal I, Ruíz-Pérez LM, González-Pacanowska D, García-Fuentes L. Calorimetric determination of thermodynamic parameters of 2'-dUMP binding to Leishmania major dUTPase. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2004; 1702:33-40. [PMID: 15450848 DOI: 10.1016/j.bbapap.2004.07.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/11/2004] [Revised: 06/29/2004] [Accepted: 07/22/2004] [Indexed: 11/25/2022]
Abstract
We have investigated the binding of 2'-deoxyuridine 5'-monophosphate (2'-dUMP) to Leishmania major deoxyuridine 5'-triphosphate nucleotide hydrolase (dUTPase) by isothermal titration microcalorimetry under different experimental conditions. Binding to dimeric L. major dUTPase is a non-cooperative process, with a stoichiometry of 1 molecule of 2'-dUMP per subunit. The utilization of buffers with different ionization enthalpies has allowed us to conclude that the formation of the 2'-dUMP-dUTPase complex, at pH 7.5 and 30 degrees C, is accompanied by the uptake of 0.33 +/- 0.05 protons per dUTPase subunit from the buffer media. Moreover, 2'-dUMP shows a moderate affinity for the enzyme, and binding is enthalpically driven across the temperature range studied. Besides, whereas DeltaG degrees remains practically invariant as a function of temperature, both DeltaH and DeltaS degrees decrease with increasing temperature. The TS and TH were 23.4 and 13.6 degrees C, respectively. The temperature dependence of the enthalpy change yields a heat capacity change of DeltaCp degrees = -618.1 +/- 126.4 cal x mol(-1) x K(-1), a value low enough to discard major conformational changes, in agreement with the fitting model. An interpretation of this value in terms of solvent-accessible surface areas is provided.
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Affiliation(s)
- Irene Domínguez-Pérez
- Dpto. de Química Física, Bioquímica y Q. Inorgánica, Facultad de Ciencias Experimentales, Universidad de Almería, La Cañada de San Urbano, 04120 Almería, Spain
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Garcia-Fuentes L, Reche P, Lopez-Mayorga O, Santi DV, Gonzalez-Pacanowska D, Baron C. Thermodynamic Analysis of the Binding of 5-fluoro-2'-deoxyuridine 5'-monophosphate to Thymidylate Synthase Over a Range of Temperatures. ACTA ACUST UNITED AC 1995. [DOI: 10.1111/j.1432-1033.1995.641zz.x] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Cieśla J, Gołos B, Dzik JM, Pawełczak K, Kempny M, Makowski M, Bretner M, Kulikowski T, Machnicka B, Rzeszotarska B. Thymidylate synthases from Hymenolepis diminuta and regenerating rat liver: purification, properties, and inhibition by substrate and cofactor analogues. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1249:127-36. [PMID: 7599165 DOI: 10.1016/0167-4838(95)00032-p] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Comparative studies of thymidylate synthases, isolated from the tapeworm, Hymenolepis diminuta, and regenerating liver of its host, rat, aimed at a possibility of specific inhibition of the helminthic enzyme, are presented. While similar in structure (dimers with monomer molecular masses of 33.7 kDa and 34.9 kDa, respectively) and parameters describing interactions with substrates and products, the tapeworm and rat enzymes differed in the dependences of reaction velocity on temperature (Arrhenius plots biphasic and linear, respectively). The tapeworm, compared with the host, enzyme was less sensitive to the competitive slow-binding inhibition by 5-fluoro-dUMP and its 2-thio congener, but equally sensitive to inhibition by 4-thio-5-fluoro-dUMP, N4-hydroxy-dCMP and N4-hydroxy-5-fluoro-dCMP, the latter being more potent inhibitor of the parasite enzyme than 5-fluoro-dUMP. alpha-Anomer of 5-fluoro-dUMP behaved as a very weak competitive slow-binding inhibitor of both enzymes. Both enzymes differed markedly in sensitivity to inhibition by 10-propargyl-5,8-dideazafolate and its di- and triglutamates (pddPteGlu1-3), with pddPteGlu1 being stronger inhibitor of the mammalian enzyme, but pddPteGlu3 showing opposite specificity. Sulfonamidobenzoylglutamate analogue of pddPteGlu (pddPteSO2Glu) and 2-desamino-2-methyl derivative of this analogue (CH3pddPteSO2Glu) were weaker inhibitors of both enzymes than the parent compound. Substitution of the glutamyl residue in CH3pddPteSO2Glu with either norvaline or alanine increased inhibition potency, whereas similar substitutions with glycine, valine or phenylglycine were without a distinct effect with the host enzyme but weakened inhibition of the tapeworm enzyme.
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Affiliation(s)
- J Cieśla
- Nencki Institute of Experimental Biology, Warsaw, Poland
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4
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Mode of binding of folate analogs to thymidylate synthase. Evidence for two asymmetric but interactive substrate binding sites. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)42108-9] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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5
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Thorndike J, Kisliuk RL, Gaumont Y, Piper JR, Nair MG. Tetrahydrohomofolate polyglutamates as inhibitors of thymidylate synthase and glycinamide ribonucleotide formyltransferase in Lactobacillus casei. Arch Biochem Biophys 1990; 277:334-41. [PMID: 2106831 DOI: 10.1016/0003-9861(90)90588-p] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
In order to determine the mechanism for the effects of homofolates on growth of Lactobacillus casei, polyglutamated derivatives of homofolate (HPteGlu), dihydrohomofolate and tetrahydrohomofolate (H4HPteGlu) were synthesized and tested as inhibitors of folate-requiring enzymes. The following L. casei enzymes were examined: thymidylate synthase (TS), glycinamide ribonucleotide formyltransferase (GARFT), aminoimidazolecarboxamide ribonucleotide formyltransferase, serine hydroxymethyltransferase and dihydrofolate reductase. Polyglutamates of (6R,S)-H4HPteGlu are potent inhibitors of TS and GARFT. For example, the IC50 values of (6R,S)-H4HPteGlu6 are 0.7 microM for TS and 0.3 microM for GARFT. By contrast, the value for HPteGlu6 is greater than 10 microM for both TS and GARFT. Inhibition of TS and GARFT by (6R,S)-H4HPteGlu derivatives increases with polyglutamate chain length. For TS, the Glu5 and Glu6 derivatives of (6R,S)-H4HPteGlu are 20 and 30 times more potent than the monoglutamate, respectively. For GARFT, the Glu2-6 derivatives are 2-3 times more potent than Glu1. Inhibition of TS and GARFT by (6R,S)-H4HPteGlu polyglutamates is almost entirely due to the unnatural (6R) diastereomer at C-6. Homofolate derivatives are only weak inhibitors of aminoimidazolecarboxamide ribonucleotide formyltransferase, serine hydroxymethyltransferase, and dihydrofolate reductase. We conclude that both TS and GARFT are potential targets of (6R)-H4HPteGlu polyglutamates.
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Affiliation(s)
- J Thorndike
- Department of Biochemistry, Tufts University, Boston, Massachusetts 02111
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Affiliation(s)
- K T Douglas
- Department of Pharmacy, University of Manchester, United Kingdom
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Garvey EP, Santi DV. A stable binary complex between Leishmania major thymidylate synthase and the substrate deoxyuridylate. A slow-binding interaction. J Biol Chem 1987. [DOI: 10.1016/s0021-9258(18)48048-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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8
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Mittelstaedt DM, Schimerlik MI. Stopped-flow studies of 2'-deoxynucleotide binding to thymidylate synthase. Arch Biochem Biophys 1986; 245:417-25. [PMID: 3082285 DOI: 10.1016/0003-9861(86)90233-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The mechanism of 2'-deoxynucleotide binding to Lactobacillus casei thymidylate synthase was studied using stopped-flow kinetic techniques to monitor the decrease in intrinsic protein fluorescence upon complex formation. The data were consistent with a two-step mechanism involving a rapid preequilibrium step to form the enzyme-2'-deoxynucleotide complex followed by a slow isomerization step. Rate and equilibrium constants were determined for the three 2'-deoxynucleotides (2'-deoxyuridylate, 2'-deoxythymidylate, and 5-fluoro-2'-deoxyuridylate) as a function of temperature. Similar free energy changes were found for all 2'-deoxynucleotides; however, the enthalpy and entropy changes for each step of the reaction differed for each 2'-deoxynucleotide. The thermodynamic profiles indicated that the isomerization step stabilized the enzyme-2'-deoxynucleotide complex by an additional 1500 cal/mol.
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Ahmed F, Moore MA, Dunlap RB. A nitrocellulose-filter assay for the binary complex of 5-fluorodeoxyuridylate and Lactobacillus casei thymidylate synthetase. Anal Biochem 1985; 145:151-9. [PMID: 3923859 DOI: 10.1016/0003-2697(85)90341-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The interaction of 5-fluorodeoxyuridylate (FdUMP) with thymidylate synthetase to form a binary complex has been widely reported, yet previous attempts to detect this complex by nitrocellulose filtration have failed. In contrast, a nitrocellulose-filter-binding assay utilizing [6-3H]FdUMP which measures the interaction of the enzyme with the nucleotide is reported. Extensive washing of the nitrocellulose-filtered complex between FdUMP and the enzyme resulted in no loss of bound ligand. Following denaturation with trichloroacetic acid, intact complex was detected by nitrocellulose filtration. No binding was observed between 5-fluorodeoxyuridine and the enzyme or between FdUMP and the N-ethylmaleimide-modified enzyme. As measured by the nitrocellulose filtration method, at least a 600-fold excess of FdUMP to enzyme was required to achieve saturation. The stoichiometry of FdUMP bound to the enzyme detected at saturation was 0.5-0.6 for native samples. When identical samples were subjected to denaturation prior to filtration, the stoichiometry of nucleotide binding was 0.3-0.4.
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Cipollo KL, Lewis CA, Ellis PD, Dunlap RB. Carbon 13 nuclear magnetic resonance studies of Lactobacillus casei thymidylate synthetase containing biosynthetically incorporated [guanidino-13C]arginine. J Biol Chem 1982. [DOI: 10.1016/s0021-9258(18)34736-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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11
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Lewis C, Hopper W, Wheeler M, Dunlap R. Light spectroscopic studies of the binary complex of Lactobacillus casei thymidylate synthetase and 5-fluoro-2'-deoxyuridylate. J Biol Chem 1981. [DOI: 10.1016/s0021-9258(19)68969-6] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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Danenberg PV, Lockshin A. Fluorinated pyrimidines as tight-binding inhibitors of thymidylate synthetase. Pharmacol Ther 1981; 13:69-90. [PMID: 6455671 DOI: 10.1016/0163-7258(81)90068-1] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
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13
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Beckage MJ, Blumenstein M, Kisliuk RL. 19F NMR studies of the binding of 5-fluoro-2'-deoxyuridylate to thymidylate synthase. Mol Cell Biochem 1980; 32:45-8. [PMID: 7442655 DOI: 10.1007/bf00421294] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
In the presence of thymidylate synthase, the 19F signal of 5-fluoro-2'-deoxyuridylate is shifted upfield 0.6 ppm or 4.5 ppm depending on the enzyme preparation used. The bands of these positions represent different species of binary complex. When either binary complex is reacted with methylenetetrahydrofolate a ternary complex is formed with a 19F signal shifted 12.5 ppm upfield and broadened to 120 Hz. Substitution of the hydrogen atoms of the methylene group of methylenetetrahydrofolate with deuterium atoms results in line-narrowing of the spectrum of the ternary complex from 120 to 80 Hz indicating the close proximity of the methylene group to the fluorine atom in the ternary complex. A model compound, 5-fluoro-6-hydroxy-5-methyl-5, 6-dihydrouracil, gives a chemical shift in the same direction and of similar magnitude to that seen with the ternary complex.
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Beaudette NV, Langerman N, Kisliuk RL. A calorimetric study of the binding of 2'-deoxyuridine-5'-phosphate and its analogs to thymidylate synthetase. Arch Biochem Biophys 1980; 200:410-7. [PMID: 7436411 DOI: 10.1016/0003-9861(80)90371-9] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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15
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Beaudette NV, Langerman N. The thermodynamics of nucleotide binding to proteins. CRC CRITICAL REVIEWS IN BIOCHEMISTRY 1980; 9:145-70. [PMID: 6108194 DOI: 10.3109/10409238009105433] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Models describing the interaction of a small molecule with a protein are typically couched in terms of the stoichiometry, cooperativity, and binding free-energy change. These parameters are readily available from equilibrium dialysis experiments (or appropriate variations). With the recent advent of extremely sensitive calorimeters, it is possible to obtain thermal data for the binding reaction and, thus, the entire set of thermodynamic parameters, delta G', delta H', delta S', delta C', become readily available. This review is limited to the binding of nucleotides and nucleotide analogs to proteins for which complete thermal data are available. While the majority of such systems have been characterized by calorimetry, we have not excluded, per se, van't Hoff enthalpy determinations. The systems we have considered include, but are not limited to, thymidylate synthetase, phosphorylase, several dehydrogenases, aldolase, glutamine synthetase, hemoglobin, asparate transcarbamylase, and ribonuclease. A variety of forces contribute to the total free-energy change upon ligand binding. These forces include ionic, van der Waals, hydrogen bond, and hydrophobic. In several cases, properly designed experiments have allowed a partial resolution of the individual contributions of these various forces. Variation of easily accessible conditions such as temperature, pH, ionic strength, or solvent third component produce changes in the set of thermodynamic parameters which lead to the resolution of the forces. The generality of heat effects makes this method very useful for studying the involvement of protons in binding reactions. The variation in the magnitude and direction (release or uptake) of the proton flux is readily studied by determining the apparent heat of reaction at constant pH, ionic strength, and temperature in two or more buffers of differing heat of ionization. This application has been exploited in several cases and is examined in great detail. An overview of the results in these systems to date suggests that several trends observed in the thermodynamic parameters need to be confirmed by further experimentation and, if they hold, an appropriate theoretical basis must be developed to aid in their interpretation.
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Thymidylate synthetase and 2'-deoxyuridylate form a tight complex in the presence of pteroyltriglutamate. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(19)86309-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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17
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Beckage MJ, Blumenstein M, Kisliuk RL. 31P NMR studies on the interaction of deoxyuridylate with thymidylate synthase. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 571:157-61. [PMID: 40612 DOI: 10.1016/0005-2744(79)90236-5] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The 31P nuclear magnetic resonance signal of deoxyuridylate was studied in the presence and absence of thymidlate synthase. In the absence of enzyme the chemical shift of deoxyuridylate is pH dependent with a pKa of 6.25. In the presence of enzyme, a peak corresponding to the dianioinc form of deoxyuridylate is observed which is independent of pH between pH 5.7 and pH 7.4. The pKa of the phosphate in the deoxyuridylate-thymidylate synthase complex is therefore less than 5. The release of inorganic phosphate from deoxyuridylate catalyzed by contaminating phosphatase was also observed.
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18
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Danenberg K, Danenberg P. Evidence for a sequential interaction of the subunits of thymidylate synthetase. J Biol Chem 1979. [DOI: 10.1016/s0021-9258(17)30013-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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19
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Plese PC, Dunlap RB. The effect of thiols on the sulfhydryl content and nucleotide binding of thymidylate synthetase. Biochem Biophys Res Commun 1978; 85:92-8. [PMID: 743294 DOI: 10.1016/s0006-291x(78)80015-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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20
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Lewis CA, Ellis PD, Dunlap RB. 19F NMR of the 5-fluorodeoxyuridylate-thymidylate synthetase binary complex. Biochem Biophys Res Commun 1978; 83:1509-17. [PMID: 100115 DOI: 10.1016/0006-291x(78)91392-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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22
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Plante LT, Gaumont Y, Kisliuk RL. Nalpha-(pteroyltetra (gamma-glutamyl))-lysine as a ligand for the purification of thymidylate synthetase by affinity chromatography. PREPARATIVE BIOCHEMISTRY 1978; 8:91-8. [PMID: 714878 DOI: 10.1080/00327487808069051] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Nalpha-(pteroyltetra (gamma-glutamyl))-lysine Sepharose was synthesized and shown to be a stable high capacity affinity matrix capable of bringing about the purification of Lactobacillus casei thymidylate synthetase to maximum specific activity from crude extracts in high yield. Under conditions optimal for binding of thymidylate synthetase, dihydrofolate reductase was not bound.
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Galivan J, Noonan J, Maley F. Studies on the reactivity of the essential cysteine of thymidylate synthetase. Arch Biochem Biophys 1977; 184:336-45. [PMID: 413488 DOI: 10.1016/0003-9861(77)90360-5] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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24
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Galivan J, Maley F, Baugh CM. Protective effect of the pteroylpolyglutamates and phosphate on the proteolytic inactivation of thymidylate synthetase. Arch Biochem Biophys 1977; 184:346-54. [PMID: 413489 DOI: 10.1016/0003-9861(77)90361-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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