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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: 13] [Impact Index Per Article: 3.3] [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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Affiliation(s)
- Perry Allen Frey
- From the Department of Biochemistry, University of Wisconsin-Madison, Madison, Wisconsin 53706
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Frey PA. Chiral phosphorothioates: stereochemical analysis of enzymatic substitution at phosphorus. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 62:119-201. [PMID: 2658487 DOI: 10.1002/9780470123089.ch4] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- P A Frey
- Institute for Enzyme Research, Graduate School, College of Agricultural and Life Sciences, University of Wisconsin, Madison 53705
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Newman JA, Das SK, Sedelnikova SE, Rice DW. The crystal structure of an ADP complex of Bacillus subtilis pyridoxal kinase provides evidence for the parallel emergence of enzyme activity during evolution. J Mol Biol 2006; 363:520-30. [PMID: 16978644 DOI: 10.1016/j.jmb.2006.08.013] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 08/04/2006] [Accepted: 08/07/2006] [Indexed: 11/28/2022]
Abstract
Pyridoxal kinase catalyses the phosphorylation of pyridoxal, pyridoxine and pyridoxamine to their 5' phosphates and plays an important role in the pyridoxal 5' phosphate salvage pathway. The crystal structure of a dimeric pyridoxal kinase from Bacillus subtilis has been solved in complex with ADP to 2.8 A resolution. Analysis of the structure suggests that binding of the nucleotide induces the ordering of two loops, which operate independently to close a flap on the active site. Comparisons with other ribokinase superfamily members reveal that B. subtilis pyridoxal kinase is more closely related in both sequence and structure to the family of HMPP kinases than to other pyridoxal kinases, suggesting that this structure represents the first for a novel family of "HMPP kinase-like" pyridoxal kinases. Moreover this further suggests that this enzyme activity has evolved independently on multiple occasions from within the ribokinase superfamily.
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Affiliation(s)
- Joseph A Newman
- Krebs Institute for Biomolecular Research, Department of Molecular Biology and Biotechnology, The University of Sheffield, Sheffield S10 2TN, UK
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Datta R, Das I, Sen B, Chakraborty A, Adak S, Mandal C, Datta A. Mutational analysis of the active-site residues crucial for catalytic activity of adenosine kinase from Leishmania donovani. Biochem J 2006; 387:591-600. [PMID: 15606359 PMCID: PMC1134988 DOI: 10.1042/bj20041733] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Leishmania donovani adenosine kinase (LdAdK) plays a pivotal role in scavenging of purines from the host. Exploiting interspecies homology and structural co-ordinates of the enzyme from other sources, we generated a model of LdAdK that led us to target several amino acid residues (namely Gly-62, Arg-69, Arg-131 and Asp-299). Replacement of Gly-62 with aspartate caused a drastic reduction in catalytic activity, with decreased affinity for either substrate. Asp-299 was found to be catalytically indispensable. Mutation of either Arg-131 or Arg-69 caused a significant reduction in kcat. R69A (Arg-69-->Ala) and R131A mutants exhibited unaltered K(m) for either substrate, whereas ATP K(m) for R69K increased 6-fold. Importance of both of the arginine residues was reaffirmed by the R69K/R131A double mutant, which exhibited approx. 0.5% residual activity with a large increase in ATP K(m). Phenylglyoxal, which inhibits the wild-type enzyme, also inactivated the arginine mutants to different extents. Adenosine protected both of the Arg-69 mutants, but not the R131A variant, from inactivation. Binding experiments revealed that the AMP-binding property of R69K or R69A and D299A mutants remained largely unaltered, but R131A and R69K/R131A mutants lost their AMP binding ability significantly. The G62D mutant did not bind AMP at all. Free energy calculations indicated that Arg-69 and Arg-131 are functionally independent. Thus, apart from the mandatory requirement of flexibility around the diglycyl (Gly-61-Gly-62) motif, our results identified Asp-299 and Arg-131 as key catalytic residues, with the former functioning as the proton abstractor from the 5'-OH of adenosine, while the latter acts as a bidentate electrophile to stabilize the negative charge on the leaving group during the phosphate transfer. Moreover, the positive charge distribution of Arg-69 probably helps in maintaining the flexibility of the alpha-3 helix needed for proper domain movement. These findings provide the first comprehensive biochemical evidence implicating the mechanistic roles of the functionally important residues of this chemotherapeutically exploitable enzyme.
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Affiliation(s)
- Rupak Datta
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Ishita Das
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Banibrata Sen
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Anutosh Chakraborty
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Subrata Adak
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Chhabinath Mandal
- †Division of Drug Design, Development and Molecular Modelling, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
| | - Alok K. Datta
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4, Raja S.C. Mullick Road, Kolkata 700 032, India
- To whom correspondence should be addressed (email )
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Datta R, Das I, Sen B, Chakraborty A, Adak S, Mandal C, Datta A. Homology-model-guided site-specific mutagenesis reveals the mechanisms of substrate binding and product-regulation of adenosine kinase from Leishmania donovani. Biochem J 2006; 394:35-42. [PMID: 16271040 PMCID: PMC1386000 DOI: 10.1042/bj20051513] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Despite designating catalytic roles of Asp299 and Arg131 during the transfer of gamma-phosphate from ATP to Ado (adenosine) [R. Datta, Das, Sen, Chakraborty, Adak, Mandal and A. K. Datta (2005) Biochem. J. 387, 591-600], the mechanisms that determine binding of substrate and cause product inhibition of adenosine kinase from Leishmania donovani remained unclear. In the present study, employing homology-model-guided site-specific protein mutagenesis, we show that Asp16 is indispensable, since its replacement with either valine or arginine resulted in a >200-fold increase in K(m) (Ado) with a 1000-fold decrease in k(cat)/K(m), implying its critical importance in Ado binding. Even glutamate replacement was not tolerated, indicating the essentiality of Asp16 in the maintenance of steric complementarity of the binding pocket. Use of 2'or 3'-deoxygenated Ado as substrates indicated that, although both the hydroxy groups play important roles in the formation of the enzyme-Ado complex, the binding energy (DeltaDeltaG(B)) contribution of the former was greater than the latter, suggesting possible formation of a bidentate hydrogen bond between Asp16 and the adenosyl ribose. Interestingly, AMP-inhibition and AMP-binding studies revealed that, unlike the R131A mutant, which showed abrogated AMP-binding and insensitivity towards AMP inhibition despite its unaltered K(m) (Ado), all the Asp16 mutants bound AMP efficiently and displayed AMP-sensitive catalytic activity, suggesting disparate mechanisms of binding of Ado and AMP. Molecular docking revealed that, although both Ado and AMP apparently occupied the same binding pocket, Ado binds in a manner that is subtly different from AMP binding, which relies heavily on hydrogen-bonding with Arg131 and thus creates an appropriate environment for competition with Ado. Hence, besides its role in catalysis, an additional novel function of the Arg131 residue as an effector of product-mediated enzyme regulation is proposed.
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Affiliation(s)
- Rupak Datta
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India
| | - Ishita Das
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India
| | - Banibrata Sen
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India
| | - Anutosh Chakraborty
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India
| | - Subrata Adak
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India
| | - Chhabinath Mandal
- †Division of Drug Design, Development and Molecular Modeling, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India
| | - Alok K. Datta
- *Division of Infectious Diseases, Leishmania Group, Indian Institute of Chemical Biology, 4 Raja S.C. Mullick Road, Kolkata 700032, India
- To whom correspondence should be addressed (email )
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Eckstein F. Phosphorothioatanaloga von Nucleotiden - Werkzeuge zur Untersuchung biochemischer Prozesse. Angew Chem Int Ed Engl 2006. [DOI: 10.1002/ange.19830950603] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Koziołkiewicz M, Owczarek A, Wójcik M, Domański K, Guga P, Stec WJ. Retention of configuration in the action of human plasma 3'-exonuclease on oligo(deoxynucleoside phosphorothioate). A new method for assignment of absolute configuration at phosphorus in isotopomeric deoxyadenosine 5'-O-[(18)O]phosphorothioate. J Am Chem Soc 2002; 124:4623-7. [PMID: 11971710 DOI: 10.1021/ja017187u] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A new method of analysis has allowed the exonucleolytic cleavage by human 3'-exonuclease to be determined. Hydrolysis by human plasma 3'-exonuclease proceeds with retention of configuration at phosphorus. The new method determines the sense of chirality at phosphorus in isotopomeric adenosine 5'-O-[(18)O]phosphorothioates. This is based on stereospecific two-step conversion of the mono-thionucleotide into the corresponding deoxyadenosine 5'-O-alpha-[(18)O]thiotriphosphate, followed by the use of terminal deoxyribonucleotidyl transferase and MALDI TOF mass spectrometry of the resulting elongated primer. Retention of configuration in the reaction of plasma 3'-exonuclease implies a two-step mechanism with two displacements on phosphorus. Inversion at each step leads to overall retention.
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Affiliation(s)
- Maria Koziołkiewicz
- Department of Bioorganic Chemistry, Centre of Molecular and Macromolecular Studies, Polish Academy of Sciences, Sienkiewicza 112, 90-363 Łódź, Poland
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Cheng G, Bennett EM, Begley TP, Ealick SE. Crystal structure of 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate kinase from Salmonella typhimurium at 2.3 A resolution. Structure 2002; 10:225-35. [PMID: 11839308 DOI: 10.1016/s0969-2126(02)00708-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The crystal structures of Salmonella typhimurium 4-amino-5-hydroxymethyl-2-methylpyrimidine phosphate kinase (HMPP kinase) and its complex with substrate HMP have been determined. HMPP kinase catalyzes two separate ATP-dependent phosphorylation reactions and is an essential enzyme in the thiamin biosynthetic pathway. HMPP kinase is a homodimer with one active site per monomer and is structurally homologous to members of the ribokinase family. A comparison of the structure of HMPP kinase with other members of the ribokinase family suggests an evolutionary progression. Modeling studies suggest that HMPP kinase catalyzes both of its phosphorylation reactions using in-line displacement mechanisms. We propose that the active site accommodates the two separate reactions by providing two different binding modes for the phosphate group of HMP phosphate.
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Affiliation(s)
- Gong Cheng
- Department of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853, USA
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Maj MC, Gupta RS. The effect of inorganic phosphate on the activity of bacterial ribokinase. JOURNAL OF PROTEIN CHEMISTRY 2001; 20:139-44. [PMID: 11563694 DOI: 10.1023/a:1011081508171] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Ribokinase and adenosine kinase are both members of the PfkB family of carbohydrate kinases. The activity of mammalian adenosine kinase was previously shown to be affected by pentavalent ions (PVI). We now present evidence that the catalytic activity of E. coli ribokinase is also affected by PVI, increasing both the velocity and affinity of the enzyme for D-ribose. The Km, for ribose decreased from 0.61 mM to 0.21, 0.25, and 0.33 mM in the presence of 20 mM phosphate, arsenate, and vanadate, respectively. The activity of ribokinase was stimulated in a hyperbolic fashion, with the maximum velocity increasing 23-fold, 13-fold, and 11-fold under the same conditions, respectively. Activity was also affected upon the addition of phosphoenolpyruvate, suggesting that phosphorylated metabolites could be involved in enzymatic control. The similar effect of PVI on distantly related enzymes suggests that a common mechanism for activity is shared among PfkB family members.
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Affiliation(s)
- M C Maj
- Department of Biochemistry, McMaster University, Hamilton, Ontario, Canada
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Maj MC, Singh B, Gupta RS. Structure-activity studies on mammalian adenosine kinase. Biochem Biophys Res Commun 2000; 275:386-93. [PMID: 10964675 DOI: 10.1006/bbrc.2000.3307] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The structure-activity relationship for Chinese hamster adenosine kinase (AK) was examined by making systematic deletions from the N- and C-terminal ends. The first 16 a.a. residues from the N-terminal end, which likely form a random coil, can be deleted without any effect on AK activity or stability. The successive removal of the next 11 residues, which stabilize the first beta structure of the protein, leads to a progressive loss of AK activity from 100 to about 3%. The loss in activity is accompanied by increasing thermal instability and a slight increase in the K(m) for adenosine. All deletions beyond residue M28, which should cause disruption of the tertiary structure, are devoid of AK activity. The residues at the C-terminal end form a substructure involved in the stability of the "adenosine 2 binding site" and removal of any residues results in significant loss of activity. Successive removal of the first 10 residues from this end causes progressive decrease in AK activity to about the 2% level, accompanied by a five-fold increase in the K(m) for ATP, supporting the view that the adenosine 2 binding site located near the C-terminal end is the ATP binding site. All deletions beyond residue R348, which forms two salt bridges with the ATP binding site, are inactive. Site-directed replacement of an aspartic acid residue (D316), which is postulated to function in the transfer of phosphate from ATP to adenosine by either asparagine or glutamic acid, leads to complete loss of activity, supporting the proposed role of D316 as the catalytic base.
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Affiliation(s)
- M C Maj
- Department of Biochemistry, McMaster University, Hamilton, Ontario, L8N 3Z5, Canada
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Stec WJ, Woźniak LA, Pyzowski J, Niewiarowski W. Novel cost-effective methanephosphonoanilidothioate approach to the stereoselective synthesis of dinucleoside (3',5')-methanephosphonates. ANTISENSE & NUCLEIC ACID DRUG DEVELOPMENT 1997; 7:381-95. [PMID: 9303190 DOI: 10.1089/oli.1.1997.7.381] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A new method of stereoselective preparation of di(2'-deoxy or 2'-OMe)ribonucleoside (3',5')-methanephosphonate 5 is presented. The DBU/LiCl-assisted reaction of 5'-O-DMT-(2'-deoxy or 2'-OMe)ribonucleoside 3'-O-(S-alkyl methanephosphonothioate) 9 with 5'-OH nucleosides proceeds with full stereospecificity, giving 5 in moderate to good yield. The conversion of 5'-O-DMT-(2'-deoxy or 2'-OMe) ribonucleoside 3'-methanephosphonoanilidothioates 8 and 3'-O-methanephosphonoanilidates 10 by means of NaH/CX2 (X = O,S) followed by S-alkylation leads to monomers 9, with the possibility of use of both separated diastereomers of 8 for the preparation of one selected diastereomer of 5. The relative configuration at the P atom in 2'-OMe and deoxynucleoside derivatives of compounds 9 was established by means of stereoselective degradation of nucleoside 3'-O-methanephosphonothioates 11 (precursors of 9) with nuclease P1.
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Affiliation(s)
- W J Stec
- Department of Bioorganic Chemistry, Polish Academy of Sciences, Lódź, Poland
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Eckstein F. Phosphorothioate Analogues of Nucleotides?Tools for the Investigation of Biochemical Processes. ACTA ACUST UNITED AC 1983. [DOI: 10.1002/anie.198304233] [Citation(s) in RCA: 162] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Eckstein F, Romaniuk PJ, Connolly BA. Stereochemistry of enzymic phosphoryl and nucleotidyl transfer. Methods Enzymol 1982; 87:197-212. [PMID: 6294448 DOI: 10.1016/s0076-6879(82)87015-8] [Citation(s) in RCA: 38] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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17
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Frey PA, Richard JP, Ho HT, Brody RS, Sammons RD, Sheu KF. Stereochemistry of selected phosphotransferases and nucleotidyltransferases. Methods Enzymol 1982; 87:213-35. [PMID: 6294450 DOI: 10.1016/s0076-6879(82)87016-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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18
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Frey PA. Chapter 5 Stereochemistry of enzymatic substitution at phosphorus. ACTA ACUST UNITED AC 1982. [DOI: 10.1016/s0167-7306(08)60396-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/10/2023]
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