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Malinowska M, Czerniecka M, Jastrzebska I, Ratkiewicz A, Tylicki A, Wawrusiewicz-Kurylonek N. In Vitro and In Silico Studies on Cytotoxic Properties of Oxythiamine and 2'-Methylthiamine. Int J Mol Sci 2024; 25:4359. [PMID: 38673944 PMCID: PMC11050282 DOI: 10.3390/ijms25084359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 04/06/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
It is important to search for cytostatic compounds in order to fight cancer. One of them could be 2'-methylthiamine, which is a thiamine antimetabolite with an additional methyl group at the C-2 carbon of thiazole. So far, the cytostatic potential of 2'-methylthiamine has not been studied. We have come forward with a simplified method of synthesis using commercially available substrates and presented a comparison of its effects, as boosted by oxythiamine, on normal skin fibroblasts and HeLa cancer cells, having adopted in vitro culture techniques. Oxythiamine has been found to inhibit the growth and metabolism of cancer cells significantly better than 2'-methylthiamine (GI50 36 and 107 µM, respectively), while 2'-methylthiamine is more selective for cancer cells than oxythiamine (SI = 180 and 153, respectively). Docking analyses have revealed that 2'-methylthiamine (ΔG -8.2 kcal/mol) demonstrates a better affinity with thiamine pyrophosphokinase than thiamine (ΔG -7.5 kcal/mol ) and oxythiamine (ΔG -7.0 kcal/mol), which includes 2'-methylthiamine as a potential cytostatic. Our results suggest that the limited effect of 2'-methylthiamine on HeLa arises from the related arduous transport as compared to oxythiamine. Given that 2'-methylthiamine may possibly inhibit thiamine pyrophosphokinase, it could once again be considered a potential cytostatic. Thus, research should be carried out in order to find the best way to improve the transport of 2'-methylthiamine into cells, which may trigger its cytostatic properties.
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Affiliation(s)
- Marta Malinowska
- Faculty of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland; (M.M.); (I.J.)
| | - Magdalena Czerniecka
- Faculty of Biology, University of Bialystok, Ciolkowskiego 1J, 15-245 Bialystok, Poland;
- Laboratory of Tissue Culture, Department of Biology, University of Bialystok, Ciolkowskiego 1J, 15-245 Bialystok, Poland
| | - Izabella Jastrzebska
- Faculty of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland; (M.M.); (I.J.)
| | - Artur Ratkiewicz
- Faculty of Chemistry, University of Bialystok, Ciolkowskiego 1K, 15-245 Bialystok, Poland; (M.M.); (I.J.)
| | - Adam Tylicki
- Faculty of Biology, University of Bialystok, Ciolkowskiego 1J, 15-245 Bialystok, Poland;
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Sambon M, Pavlova O, Alhama-Riba J, Wins P, Brans A, Bettendorff L. Product inhibition of mammalian thiamine pyrophosphokinase is an important mechanism for maintaining thiamine diphosphate homeostasis. Biochim Biophys Acta Gen Subj 2022; 1866:130071. [PMID: 34942318 DOI: 10.1016/j.bbagen.2021.130071] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/04/2021] [Accepted: 12/15/2021] [Indexed: 11/20/2022]
Abstract
BACKGROUND Thiamine diphosphate (ThDP), an indispensable cofactor for oxidative energy metabolism, is synthesized through the reaction thiamine + ATP ⇆ ThDP + AMP, catalyzed by thiamine pyrophosphokinase 1 (TPK1), a cytosolic dimeric enzyme. It was claimed that the equilibrium of the reaction is in favor of the formation of thiamine and ATP, at odds with thermodynamic calculations. Here we show that this discrepancy is due to feedback inhibition by the product ThDP. METHODS We used a purified recombinant mouse TPK1 to study reaction kinetics in the forward (physiological) and for the first time also in the reverse direction. RESULTS Keq values reported previously are strongly underestimated, due to the fact the reaction in the forward direction rapidly slows down and reaches a pseudo-equilibrium as ThDP accumulates. We found that ThDP is a potent non-competitive inhibitor (Ki ≈ 0.4 μM) of the forward reaction. In the reverse direction, a true equilibrium is reached with a Keq of about 2 × 10-5, strongly in favor of ThDP formation. In the reverse direction, we found a very low Km for ThDP (0.05 μM), in agreement with a tight binding of ThDP to the enzyme. GENERAL SIGNIFICANCE Inhibition of TPK1 by ThDP explains why intracellular ThDP levels remain low after administration of even very high doses of thiamine. Understanding the consequences of this feedback inhibition is essential for developing reliable methods for measuring TPK activity in tissue extracts and for optimizing the therapeutic use of thiamine and its prodrugs with higher bioavailability under pathological conditions.
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Affiliation(s)
- Margaux Sambon
- Laboratory of Neurophysiology, GIGA-Neurosciences, University of Liege, Liege, Belgium
| | - Oleksandra Pavlova
- Palladin Institute of Biochemistry, National Academy of Sciences of Ukraine, Kyiv, Ukraine
| | - Judit Alhama-Riba
- Laboratory of Neurophysiology, GIGA-Neurosciences, University of Liege, Liege, Belgium; University of Girona, Faculty of Sciences, Spain
| | - Pierre Wins
- Laboratory of Neurophysiology, GIGA-Neurosciences, University of Liege, Liege, Belgium
| | - Alain Brans
- Protein Factory, Center for Protein Engineering, University of Liege, Liege, Belgium
| | - Lucien Bettendorff
- Laboratory of Neurophysiology, GIGA-Neurosciences, University of Liege, Liege, Belgium.
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Orishaka OV, Vovchuk IL, Petrov SA. [Extracting and study of biochemical properties of thiamine pyrophosphokinase from non-malignant and tumor tissue of myometrium]. BIOMEDITSINSKAIA KHIMIIA 2014; 60:602-607. [PMID: 25386891 DOI: 10.18097/pbmc20146005602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The method of extraction and purification of thiamine pyrophosphokinase from non-malignant and tumor tissue of myometrium has been elaborated. Kinetic characteristics of T-kinase from non-malignant and tumor tissue of women myometrium have been studied. It has been shown, that malignization of myometrium is accompanied by a decrease in affinity of thiamine pyrophosphokinase from tumor to thiamine and by an increase in sensitivity of the enzyme from tumor to thiochrome.
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de Fátima Oliveira-Silva I, Pereira SRC, Fernandes PA, Ribeiro AF, Pires RGW, Ribeiro AM. Mild thiamine deficiency and chronic ethanol consumption modulate acetylcholinesterase activity change and spatial memory performance in a water maze task. J Mol Neurosci 2014; 55:217-226. [PMID: 24770900 DOI: 10.1007/s12031-014-0306-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Accepted: 04/08/2014] [Indexed: 11/25/2022]
Abstract
Chronic thiamine deficiency may be responsible for pathologic changes in the brains of alcoholics, and subclinical episodes of this vitamin deficiency may cause cumulative brain damage. In the present work, the chronic effects of ethanol and its association to a mild thiamine deficiency episode (subclinical model) on neocortical and hippocampal acetylcholinesterase activity were assessed along with their possible association to spatial cognitive dysfunction. The results indicate that in the beginning of the neurodegenerative process, before the appearance of brain lesions, chronic ethanol consumption reverses the effects of mild thiamine deficiency on both spatial cognitive performance and acetylcholinesterase activity without having significant effects on any morphometric parameter.
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Affiliation(s)
- Ieda de Fátima Oliveira-Silva
- Departamento de Análises Clínicas e Toxicológicas - Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Silvia R Castanheira Pereira
- Programa de Pós-graduação em Neurociências, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Paula A Fernandes
- Departamento de Análises Clínicas e Toxicológicas - Faculdade de Farmácia, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Andrea F Ribeiro
- Programa de Pós-graduação em Neurociências, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil
| | - Rita G W Pires
- Departamento de Ciências Fisiológicas/Centro Biomédico-Laboratório de Neurobiologia Molecular e Comportamental, Universidade Federal do Espírito Santo, Vitória, 29043-910, Brazil
| | - Angela Maria Ribeiro
- Programa de Pós-graduação em Neurociências, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil.
- Departamento de Bioquímica e Imunologia, Laboratório de Neurociências Comportamental e Molecular, LaNeC, Faculdade de Filosofia e Ciências Humanas, FaFiCH, Universidade Federal de Minas Gerais, Belo Horizonte, 31270-010, Brazil.
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Krautwald M, Leech D, Horne S, Steele ML, Forbes J, Rahmadi A, Griffith R, Münch G. The Advanced Glycation End Product-Lowering Agent ALT-711 Is a Low-Affinity Inhibitor of Thiamine Diphosphokinase. Rejuvenation Res 2011; 14:383-91. [DOI: 10.1089/rej.2010.1143] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- Martina Krautwald
- Department of Biochemistry and Molecular Biochemistry, School of Pharmacy and Molecular Science, James Cook University, Townsville, Australia
| | - Dale Leech
- Department of Biochemistry and Molecular Biochemistry, School of Pharmacy and Molecular Science, James Cook University, Townsville, Australia
| | - Stacey Horne
- Department of Pharmacology, School of Medicine, University of Western Sydney, Campbelltown, Australia
| | - Megan L. Steele
- JDRF Einstein Centre for Diabetes Complications, Baker IDI Heart and Diabetes Institute, Melbourne, Australia
| | - Josephine Forbes
- Department of Pharmacology, School of Medicine, University of Western Sydney, Campbelltown, Australia
| | - Anton Rahmadi
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Sydney, Australia
| | - Renate Griffith
- Department of Pharmacology, School of Medicine, University of Western Sydney, Campbelltown, Australia
| | - Gerald Münch
- Department of Pharmacology, School of Medicine, University of Western Sydney, Campbelltown, Australia
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Parkhomenko YM, Kudryavtsev PA, Pylypchuk SY, Chekhivska LI, Stepanenko SP, Sergiichuk AA, Bunik VI. Chronic alcoholism in rats induces a compensatory response, preserving brain thiamine diphosphate, but the brain 2-oxo acid dehydrogenases are inactivated despite unchanged coenzyme levels. J Neurochem 2011; 117:1055-65. [DOI: 10.1111/j.1471-4159.2011.07283.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Eschbach ML, Müller IB, Gilberger TW, Walter RD, Wrenger C. The human malaria parasite Plasmodium falciparum expresses an atypical N-terminally extended pyrophosphokinase with specificity for thiamine. Biol Chem 2007; 387:1583-91. [PMID: 17132104 DOI: 10.1515/bc.2006.197] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Vitamin B(1) is an essential cofactor for key enzymes such as 2-oxoglutarate dehydrogenase and pyruvate dehydrogenase. Plants, bacteria and fungi, as well as Plasmodium falciparum, are capable of synthesising vitamin B(1)de novo, whereas mammals have to take up this cofactor from their diet. Thiamine, a B(1) vitamer, has to be pyrophosphorylated by thiamine pyrophosphokinase (TPK) to the active form. The human malaria parasite P. falciparum expresses an N-terminally extended pyrophosphokinase throughout the entire erythrocytic life cycle, which was analysed by Northern and Western blotting. The recombinant enzyme shows a specific activity of 27 nmol min(-1) mg(-1) protein and specificity for thiamine with a K(m) value of 73 microM, while thiamine monophosphate is not accepted. Mutational analysis of the N-terminal extension of the plasmodial TPK showed that it influences thiamine binding as well as metal dependence, which suggests N-terminal participation in the conformation of the active site. Protein sequences of various plasmodial TPKs were analysed for their phylogeny, which classified the Plasmodium TPKs to a group distinct from the mammalian TPKs. To verify the location of the parasite TPK within the cell, immunofluorescence analyses were performed. Co-staining of PfTPK with a GFP marker visualised its cytosolic localisation.
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Sensitivity to Thiamine Deficiency in Cultured Human Cells is Dependent on Cell Type and is Enhanced in Cells From Thiamine-Responsive Megaloblastic Anemia Patients 11This work was supported by Grant AA10433 from the National Institute on Alcohol Abuse and Alcoholism and in part by the Vanderbilt Clinical Research Center (CRR-GCRC 5MO1RR00095) and the John F. Kennedy Center for Research on Human Development through a core grant (P30-HD15052) from NICHHD. J Nutr Biochem 1998. [DOI: 10.1016/s0955-2863(97)00187-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Abstract
We recently showed that thiamine uptake by neuroblastoma cells is mediated by two saturable transport system: the first with high affinity for thiamine (Km = 35 nM) is blocked by veratridine; the other, with low affinity is blocked by Ca2+. The driving force for thiamine uptake is its phosphorylation to thiamine diphosphate (TDP) by thiamine pyrophosphokinase and subsequent binding of this cofactor to apoenzymes. Our results suggest that cells of neuronal origin possess mechanisms regulating the intracellular concentration of thiamine. At low external thiamine, the vitamin is taken up by a high-affinity transporter and pyrophosphorylated in thiamine diphosphate (TDP): this is the TDP pool of slow turnover. An intraover extracellular concentration gradient of free thiamine is observed at low external concentration of the vitamin. At higher external thiamine concentration, TDP accumulation is limited by the binding capacity to the apoenzymes and unbound TDP (i.e. a small pool of fast turnover) is quickly hydrolyzed. Thiamine is slowly released by the cells by at least two different mechanisms. The first, accounting for a maximum of 50% of total thiamine release, is stimulated by external thiamine and is blocked by veratridine, suggesting that it is a self-exchange mechanism catalyzed by the high affinity thiamine transporter. The remaining thiamine efflux is neither sensitive to veratridine nor to Ca2+ and its mechanism is unknown. About 25% of intracellular thiamine is not released, even after treatment of the cells with digitonin, thus maintaining an apparent gradient. This suggests a binding or sequestration in intracellular compartments.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- L Bettendorff
- Laboratory of Neurochemistry, University of Liège, Belgium
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Romanenko AV, Gnatenko VM, Vladimirova IA. Effect of thiamine on neuromuscular transmission in smooth muscles. NEUROPHYSIOLOGY+ 1994. [DOI: 10.1007/bf01053581] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Affiliation(s)
- L Bettendorff
- Laboratory of Neurochemistry, University of Liège, Belgium
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12
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Bettendorff L. The compartmentation of phosphorylated thiamine derivatives in cultured neuroblastoma cells. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1222:7-14. [PMID: 8186267 DOI: 10.1016/0167-4889(94)90019-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Thiamine transport in cultured neuroblastoma cells is mediated by a high-affinity carrier (KM = 40 nM). In contrast, the uptake of the more hydrophobic sulbutiamine (isobutyrylthiamine disulfide) is unsaturable and its initial transport rate is 20-times faster than for thiamine. In the cytoplasm, sulbutiamine is rapidly hydrolyzed and reduced to free thiamine, the overall process resulting in a rapid and concentrative thiamine accumulation. Incorporation of radioactivity from [14C]thiamine or [14C]sulbutiamine into intracellular thiamine diphosphate is slow in both cases. Despite the fact that the diphosphate is probably the direct precursor for both thiamine monophosphate and triphosphate, the specific radioactivity increased much faster for the latter two compounds than for thiamine diphosphate. This suggests the existence of two pools of thiamine diphosphate, the larger one having a very slow turnover (about 17 h); a much smaller, rapidly turning over pool would be the precursor of thiamine mono- and triphosphate. The turnover time for thiamine triphosphate could be estimated to be 1-2 h. When preloading the cells with [14C]sulbutiamine was followed by a chase with the same concentration of the unlabeled compound, the specific radioactivities of thiamine and thiamine monophosphate decreased exponentially as expected, but labeling of the diphosphate continued to increase slowly. Specific radioactivity of thiamine triphosphate increased first, but after 30 min it began to slowly decrease. These results show for the first time the existence of distinct thiamine diphosphate pools in the same homogeneous cell population. They also suggest a complex compartmentation of thiamine metabolism.
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Affiliation(s)
- L Bettendorff
- Laboratory of General and Comparative Biochemistry, University of Liège, Belgium
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Bettendorff L, Wins P. Mechanism of thiamine transport in neuroblastoma cells. Inhibition of a high affinity carrier by sodium channel activators and dependence of thiamine uptake on membrane potential and intracellular ATP. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)36633-4] [Citation(s) in RCA: 23] [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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Abstract
The activities of thiamine diphosphatase (TDPase), thiamine triphosphatase (TTPase), and thiamine pyrophosphokinase and the contents of thiamine and its phosphate esters were determined in rat brain cortex, cerebellum, and liver from birth to adulthood. Microsomal TTPase activity in the cerebral cortex and cerebellum increased from birth to 3 weeks, whereas that in the liver did not change during postnatal development. Microsomal TDPase activity in the cerebral cortex showed a transient increase at 1-2 weeks, but that in the cerebellum did not change during development. In contrast to the activity of the brain enzyme, that of liver microsomal TDPase increased stepwise after birth. Thiamine pyrophosphokinase activity in the cerebellum increased from birth to 3 weeks and then decreased, whereas that in the cerebral cortex and liver showed less change during development. TDP and thiamine monophosphate (TMP) levels increased after birth and plateaued at 3 weeks whereas TTP and thiamine levels showed little change during development in the cerebral cortex and cerebellum. The contents of thiamine and its phosphate esters in the liver showed more complicated changes during development. It is concluded that thiamine metabolism in the brain changes during postnatal development in a different way from that in the liver and that the development of thiamine metabolism differs among brain regions.
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Affiliation(s)
- T Matsuda
- Department of Pharmacology, Faculty of Pharmaceutical Sciences, Osaka University, Japan
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Matsuda T, Yabushita Y, Doi T, Iwata H. Regional distribution of thiamin pyrophosphokinase in rat brain. EXPERIENTIA 1985; 41:924-5. [PMID: 2988999 DOI: 10.1007/bf01970015] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The highest specific activity of thiamin pyrophosphokinase was found in the cerebellum, and lower activity in cerebral cortex and midbrain. The regional difference in the enzyme activity was similar to that in thiamin content and the influx rate in rat brain, suggesting that the enzyme is involved in the thiamin transport.
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Rindi G, Comincioli V, Reggiani C, Patrini C. Nervous tissue thiamine metabolism in vivo. II. Thiamine and its phosphoesters dynamics in different brain regions and sciatic nerve of the rat. Brain Res 1984; 293:329-42. [PMID: 6697224 DOI: 10.1016/0006-8993(84)91240-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Different steps of the metabolism of thiamine (T), thiamine mono- (TMP), pyro- (TPP) and triphosphate (TTP) in the cerebellum, brainstem, cerebral cortex and the sciatic nerve were evaluated in the rat in vivo. The radioactivity of T and its phosphoesters was determined at fixed time intervals (0.5-240 h) after an intraperitoneal injection of [14C]T (30 micrograms:1.25 muCi), under steady state conditions. The dynamics of thiamine compounds was evaluated using a compartmental mathematical model that allowed the fractional rate constants (FRC), turnover rates (TR) and turnover times to be calculated. The phosphorylation of T to TPP and the dephosphorylations of TPP to TMP and TMP to T could be estimated in all the structures investigated. Their turnover rates were found to be ordered in the sequence: cerebellum greater than brainstem greater than cerebral cortex greater than sciatic nerve. The transphosphorylation of TPP to TTP was so small that it could not be determined in a reliable way. Regional differences were found both the rate and in the composition of T and TMP mixture released from nervous structures. The shortest turnover time of TPP was found in the cerebellum, while the sciatic nerve exhibited the fastest renewal of T and TMP. In all the structures investigated TPP had a rather short turnover time, suggesting that its function might be associated to a rapid conversion into chemically different forms. The possible relationships between the rates of turnover of T compounds are the sensitivity of the nervous structures to T deficiency are discussed.
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Gubler CJ, Fleming G, Kuby SA. PURIFICATION AND KINETIC PROPERTlES OF PORCINE THIAMlN PYROPHOSPHOKINASE. Ann N Y Acad Sci 1982. [DOI: 10.1111/j.1749-6632.1982.tb31222.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Basilico V, Ferrari G, Rindi G, D'Andrea G. Thiamine intestinal transport and phosphorylation : a study in vitro of potential inhibitors of small intestinal thiamine-pyrophosphokinase using a crude enzymatic preparation. ARCHIVES INTERNATIONALES DE PHYSIOLOGIE ET DE BIOCHIMIE 1979; 87:981-85. [PMID: 94830 DOI: 10.3109/13813457909070547] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Using as enzymatic source the cytoplasmatic fraction of enterocytes isolated from the rat small intestine, thiamine-pyrophosphokinase activity was studied with a radiometric method using [thiazole-2-(14)C] thiamine. The Km value for thiamine was 2.14 X 10(-6) M and V 0.87 nmol of thiamine pyrophosphate mg-1 protein h-1. Eleven thiamine structural analogs and derivatives were assayed for their inhibitory action on the small intestine thiamine-pyrophosphokinase activity. Their Ki values were : pyrithiamine, 2.25 X 10(-6) M; thiamine monophosphate, 4 X 10(-6) M; 2'-ethylthiamine, 8 X 10(-6) M; 2'-butylthiamine, 6 X 10(-6) M; chloroethylthiamine and dimethalium, 1.5 X 10(-5) M; amprolium, 1.8 X 10(-4) M; L-582571, 1.65 X 10(-4) M; oxythiamine, 4.2 X 10(-3) M. Of the miscellaneous compounds tested (toxopyrimidine, Na-pyrophosphate, choline, L-phenylalanine, ethyl-urethane and 5-fluorouracil), none had any inhibitory action on intestinal thiamine-pyrophosphokinase activity, even if used at concentrations hundred times higher than that of labelled thiamine.
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Matsuda T, Maeda S, Baba A, Iwata H. Existence of ascorbic acid as an activator of thiamine diphosphatase in rat brain. J Neurochem 1979; 32:443-8. [PMID: 762558 DOI: 10.1111/j.1471-4159.1979.tb00369.x] [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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Wakabayashi Y, Iwashima A, Nose Y. Affinity chromatography of thiamine pyrophosphokinase from rat brain on thiamine monophosphate-agarose. Methods Enzymol 1979; 62:105-7. [PMID: 220502 DOI: 10.1016/0076-6879(79)62201-2] [Citation(s) in RCA: 5] [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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21
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Gubler CJ. A radiometric assay for thiamine pyrophosphokinase activity. Methods Enzymol 1979; 62:101-3. [PMID: 220500 DOI: 10.1016/0076-6879(79)62199-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
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Mitsuda H, Takii Y, Iwami K, Yasumoto K, Nakajima K. Enzymatic formation of thiamine pyrophosphate in plants. Methods Enzymol 1979; 62:107-11. [PMID: 220503 DOI: 10.1016/0076-6879(79)62202-4] [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: 12/13/2022]
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23
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Baba A, Matsuda T, Iwata H. Possible regulation of thiamine diphosphatase activity in rat brain microsomes by lipids. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 482:71-8. [PMID: 16655 DOI: 10.1016/0005-2744(77)90355-2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The effects of various treatments, which affect membrane structure, on microsomal thiamine diphosphatase and thiamine triphosphatase activities of rat brain, were examined. The treatment of micorosomes at alkaline pH caused a 2-fold activation of the thiamine diphosphatase, this being related to a change in membrane structure which was evidenced by a decrease of the turbidity of the microsomal suspension. Repeated freezing and thawing after hypo-osmotic treatment also increased the activity of microsomal thiamine diphosphatase. In addition, the thiamine diphosphatase activity was enhanced by treatment of the microsomes with phospholipase C or acetone. This lipid depletion resulted in a marked reduction in the apparent Km value of the thiamine diphosphatase with a corresponding loss in heat stability of the enzyme. We found further that brain thiamine diphosphatase was solubilized by Triton X-100. This decreased the phospholipid content in the preparation, but did not affect the apparent Km value and heat stability of the enzyme. In contrast with thiamine diphosphatase, thiamine triphosphatase was inactivated by treatment at alkaline pH or with acetone. However, treatment with phospholipase C did not affect the activity of thiamine triphosphatase.
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Wakabayashi Y, Iwashima A, Nose Y. Affinity chromatography of thiamin pyrophosphokinase of rat brain. BIOCHIMICA ET BIOPHYSICA ACTA 1976; 429:1085-7. [PMID: 178370 DOI: 10.1016/0005-2744(76)90355-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Affinity column chromatography coupled with thiamin monophosphate absorbs thiamin pyrophosphokinase activity in the crude extract of rat brain, and the enzyme can be eluted from the column by 0.01 mM thiamin with approximately 700-fold purification.
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