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Nascimento JF, Souza ROO, Alencar MB, Marsiccobetre S, Murillo AM, Damasceno FS, Girard RBMM, Marchese L, Luévano-Martinez LA, Achjian RW, Haanstra JR, Michels PAM, Silber AM. How much (ATP) does it cost to build a trypanosome? A theoretical study on the quantity of ATP needed to maintain and duplicate a bloodstream-form Trypanosoma brucei cell. PLoS Pathog 2023; 19:e1011522. [PMID: 37498954 PMCID: PMC10409291 DOI: 10.1371/journal.ppat.1011522] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 08/08/2023] [Accepted: 06/29/2023] [Indexed: 07/29/2023] Open
Abstract
ATP hydrolysis is required for the synthesis, transport and polymerization of monomers for macromolecules as well as for the assembly of the latter into cellular structures. Other cellular processes not directly related to synthesis of biomass, such as maintenance of membrane potential and cellular shape, also require ATP. The unicellular flagellated parasite Trypanosoma brucei has a complex digenetic life cycle. The primary energy source for this parasite in its bloodstream form (BSF) is glucose, which is abundant in the host's bloodstream. Here, we made a detailed estimation of the energy budget during the BSF cell cycle. As glycolysis is the source of most produced ATP, we calculated that a single parasite produces 6.0 x 1011 molecules of ATP/cell cycle. Total biomass production (which involves biomass maintenance and duplication) accounts for ~63% of the total energy budget, while the total biomass duplication accounts for the remaining ~37% of the ATP consumption, with in both cases translation being the most expensive process. These values allowed us to estimate a theoretical YATP of 10.1 (g biomass)/mole ATP and a theoretical [Formula: see text] of 28.6 (g biomass)/mole ATP. Flagellar motility, variant surface glycoprotein recycling, transport and maintenance of transmembrane potential account for less than 30% of the consumed ATP. Finally, there is still ~5.5% available in the budget that is being used for other cellular processes of as yet unknown cost. These data put a new perspective on the assumptions about the relative energetic weight of the processes a BSF trypanosome undergoes during its cell cycle.
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Affiliation(s)
- Janaina F. Nascimento
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Rodolpho O. O. Souza
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Mayke B. Alencar
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Sabrina Marsiccobetre
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Ana M. Murillo
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Flávia S. Damasceno
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Richard B. M. M. Girard
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Letícia Marchese
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Luis A. Luévano-Martinez
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Renan W. Achjian
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
| | - Jurgen R. Haanstra
- Systems Biology Lab, Amsterdam Institute of Molecular and Life Sciences (AIMMS), Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Paul A. M. Michels
- School of Biological Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Ariel M. Silber
- Laboratory of Biochemistry of Tryps–LaBTryps, Department of Parasitology, Institute of Biomedical Sciences, University of São Paulo–São Paulo, Brazil
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Qureshi IA, Saini M, Are S. Pyridoxal Kinase of Disease-causing Human Parasites: Structural and
Functional Insights to Understand its Role in Drug Discovery. Curr Protein Pept Sci 2022; 23:271-289. [DOI: 10.2174/1389203723666220519155025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Revised: 03/14/2022] [Accepted: 04/06/2022] [Indexed: 11/22/2022]
Abstract
Abstract:
Human parasites cause several diseased conditions with high morbidity and mortality in a
large section of the population residing in various geographical areas. Nearly three billion people suffer
from either one or many parasitic infections globally, with almost one million deaths annually. In spite
of extensive research and advancement in the medical field, no effective vaccine is available against
prominent human parasitic diseases that necessitate identification of novel targets for designing specific
inhibitors. Vitamin B6 is an important ubiquitous co-enzyme that participates in several biological processes
and plays an important role in scavenging ROS (reactive oxygen species) along with providing
resistance to oxidative stress. Moreover, the absence of the de novo vitamin B6 biosynthetic pathway in
human parasites makes this pathway indispensable for the survival of these pathogens. Pyridoxal kinase
(PdxK) is a crucial enzyme for vitamin B6 salvage pathway and participates in the process of vitamers
B6 phosphorylation. Since the parasites are dependent on pyridoxal kinase for their survival and infectivity
to the respective hosts, it is considered a promising candidate for drug discovery. The detailed
structural analysis of PdxK from disease-causing parasites has provided insights into the catalytic
mechanism of this enzyme as well as significant differences from their human counterpart. Simultaneously,
structure-based studies have identified small lead molecules that can be exploited for drug discovery
against protozoan parasites. The present review provides structural and functional highlights of
pyridoxal kinase for its implication in developing novel and potent therapeutics to combat fatal parasitic
diseases.
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Affiliation(s)
- Insaf Ahmed Qureshi
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao
Road, Hyderabad 500046, India
| | - Mayank Saini
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao
Road, Hyderabad 500046, India
| | - Sayanna Are
- Department of Biotechnology & Bioinformatics, School of Life Sciences, University of Hyderabad, Prof. C.R. Rao
Road, Hyderabad 500046, India
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Are S, Gatreddi S, Jakkula P, Qureshi IA. Structural attributes and substrate specificity of pyridoxal kinase from Leishmania donovani. Int J Biol Macromol 2020; 152:812-827. [PMID: 32105687 DOI: 10.1016/j.ijbiomac.2020.02.257] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 02/22/2020] [Accepted: 02/23/2020] [Indexed: 11/26/2022]
Abstract
The enzyme pyridoxal kinase (PdxK) catalyzes the conversion of pyridoxal to pyridoxal-5'-phosphate (PLP) using ATP as the co-factor. The product pyridoxal-5'-phosphate plays a key role in several biological processes such as transamination, decarboxylation and deamination. In the present study, full-length ORF of PdxK from Leishmania donovani (LdPdxK) was cloned and then purified using affinity chromatography. LdPdxK exists as a homo-dimer in solution and shows more activity at near to physiological pH. Biochemical analysis of LdPdxK with pyridoxal, pyridoxamine, pyridoxine and ginkgotoxin revealed its affinity preference towards different substrates. The secondary structure analysis using circular dichroism spectroscopy showed LdPdxK to be predominantly α-helical in organization which tends to decline at lower and higher pH. Simultaneously, LdPdxK was crystallized and its three-dimensional structure in complex with ADP and different substrates were determined. Crystal structure of LdPdxK delineated that it has a central core of β-sheets surrounded by α-helices with a conserved GTGD ribokinase motif. The structures of LdPdxK disclosed no major structural changes between ADP and ADP- substrate bound structures. In addition, comparative structural analysis highlighted the key differences between the active site pockets of leishmanial and human PdxK, rendering LdPdxK an attractive candidate for the designing of novel and specific inhibitors.
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Affiliation(s)
- Sayanna Are
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500 046, Telangana, India
| | - Santhosh Gatreddi
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500 046, Telangana, India
| | - Pranay Jakkula
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500 046, Telangana, India
| | - Insaf Ahmed Qureshi
- Department of Biotechnology and Bioinformatics, School of Life Sciences, University of Hyderabad, Hyderabad 500 046, Telangana, India.
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Jones DC, Alphey MS, Wyllie S, Fairlamb AH. Chemical, genetic and structural assessment of pyridoxal kinase as a drug target in the African trypanosome. Mol Microbiol 2012; 86:51-64. [PMID: 22857512 PMCID: PMC3470933 DOI: 10.1111/j.1365-2958.2012.08189.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Pyridoxal-5′-phosphate (vitamin B6) is an essential cofactor for many important enzymatic reactions such as transamination and decarboxylation. African trypanosomes are unable to synthesise vitamin B6de novo and rely on uptake of B6 vitamers such as pyridoxal and pyridoxamine from their hosts, which are subsequently phosphorylated by pyridoxal kinase (PdxK). A conditional null mutant of PdxK was generated in Trypanosoma brucei bloodstream forms showing that this enzyme is essential for growth of the parasite in vitro and for infectivity in mice. Activity of recombinant T. brucei PdxK was comparable to previously published work having a specific activity of 327 ± 13 mU mg−1 and a Kmapp with respect to pyridoxal of 29.6 ± 3.9 µM. A coupled assay was developed demonstrating that the enzyme has equivalent catalytic efficiency with pyridoxal, pyridoxamine and pyridoxine, and that ginkgotoxin is an effective pseudo substrate. A high resolution structure of PdxK in complex with ATP revealed important structural differences with the human enzyme. These findings suggest that pyridoxal kinase is an essential and druggable target that could lead to much needed alternative treatments for this devastating disease.
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Affiliation(s)
- Deuan C Jones
- Division of Biological Chemistry & Drug Discovery, College of Life Sciences, University of Dundee, Dundee, UK
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Stoffel SA, Rodenko B, Schweingruber AM, Mäser P, de Koning HP, Schweingruber ME. Biosynthesis and uptake of thiamine (vitamin B1) in bloodstream form Trypanosoma brucei brucei and interference of the vitamin with melarsen oxide activity. Int J Parasitol 2005; 36:229-36. [PMID: 16375907 DOI: 10.1016/j.ijpara.2005.10.003] [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] [Received: 07/04/2005] [Revised: 10/11/2005] [Accepted: 10/24/2005] [Indexed: 11/29/2022]
Abstract
Bloodstream forms of Trypanosoma brucei brucei were cultivated in the presence and absence of thiamine (vitamin B1) and pyridoxine (vitamin B6). The vitamins do not change growth behaviour, indicating that Trypanosoma brucei is prototrophic for the two vitamins even though in silico no bona-fide thiamine-biosynthetic genes could be identified in the T. brucei genome. Intracellularly, thiamine is mainly present in its diphosphate form. We were unable to detect significant uptake of [3H]thiamine and structural thiamine analogues such as pyrithiamine, oxithiamine and amprolium were not toxic for the bloodstream forms of T. brucei, indicating that the organism does not have an efficient uptake system for thiamine and its analogues. We have previously shown that, in the fission yeast Saccharomyces pombe, the toxicity of melarsen oxide, the pharmacologically active derivative of the frontline sleeping sickness drug melarsoprol, is abolished by thiamine and the drug is taken up by a thiamine-regulated membrane protein which is responsible for the utilization of thiamine. We show here that thiamine also has weak effects on melarsen oxide-induced growth inhibition and lysis in T. brucei. These effects were consistent with a low affinity of thiamine for the P2 adenosine transporter that is responsible for uptake of melaminophenyl arsenicals in African trypanosomes.
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Affiliation(s)
- Sabine A Stoffel
- Institute of Cell Biology, University of Bern, Baltzerstrasse 4, 3012 Bern, Switzerland
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Scott TC, Phillips MA. Characterization of Trypanosoma brucei pyridoxal kinase: purification, gene isolation and expression in Escherichia coli. Mol Biochem Parasitol 1997; 88:1-11. [PMID: 9274862 DOI: 10.1016/s0166-6851(97)00077-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Pyridoxal kinase catalyzes the ATP-dependent phosphorylation of vitamin B6, generating pyridoxal-5'-phosphate, an important cofactor for many enzymatic reactions. Pyridoxal kinase was purified 4300-fold to homogeneity from Trypanosoma brucei and peptides generated by proteolysis were subjected to amino acid sequence analysis. The peptide sequence information was used to generate a partial clone of T. brucei pyridoxal kinase by polymerase chain reaction (PCR), which in turn was used to screen a T. brucei genomic library for a full length clone. The 903-bp gene was sequenced and found to encode a 300-amino acid protein. The deduced amino acid sequence contains all of the peptide sequences obtained from the proteolytic cleavage of the native enzyme and shares 28% sequence identity with a putative Escherichia coli pyridoxal kinase, identified for its ability to compliment pyridoxal kinase deficient cells. The T. brucei pyridoxal kinase gene was expressed in E. coli and the purified enzyme was found to have pyridoxal kinase activity, confirming that this gene encodes the functional T. brucei enzyme. Native and recombinant pyridoxal kinase have a monomer molecular weight of 37 kDa by SDS-polyacrylamide gel electrophoresis (SDS-PAGE) and are dimers in solution. Native T. brucei pyridoxal kinase catalyzes the phosphorylation of pyridoxal with a specific activity of 990 nmol min(-1) per mg and apparent Km values for pyridoxal and ATP of 22 and 9 microM. respectively. Substrate inhibition is observed for pyridoxal. Similar results were obtained for the recombinant enzyme.
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Affiliation(s)
- T C Scott
- Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas 75235-9041, USA
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