1
|
Thiele I, Yehia H, Krausch N, Birkholz M, Cruz Bournazou MN, Sitanggang AB, Kraume M, Neubauer P, Kurreck A. Production of Modified Nucleosides in a Continuous Enzyme Membrane Reactor. Int J Mol Sci 2023; 24:ijms24076081. [PMID: 37047056 PMCID: PMC10094030 DOI: 10.3390/ijms24076081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 03/18/2023] [Accepted: 03/22/2023] [Indexed: 04/03/2023] Open
Abstract
Nucleoside analogues are important compounds for the treatment of viral infections or cancers. While (chemo-)enzymatic synthesis is a valuable alternative to traditional chemical methods, the feasibility of such processes is lowered by the high production cost of the biocatalyst. As continuous enzyme membrane reactors (EMR) allow the use of biocatalysts until their full inactivation, they offer a valuable alternative to batch enzymatic reactions with freely dissolved enzymes. In EMRs, the enzymes are retained in the reactor by a suitable membrane. Immobilization on carrier materials, and the associated losses in enzyme activity, can thus be avoided. Therefore, we validated the applicability of EMRs for the synthesis of natural and dihalogenated nucleosides, using one-pot transglycosylation reactions. Over a period of 55 days, 2′-deoxyadenosine was produced continuously, with a product yield >90%. The dihalogenated nucleoside analogues 2,6-dichloropurine-2′-deoxyribonucleoside and 6-chloro-2-fluoro-2′-deoxyribonucleoside were also produced, with high conversion, but for shorter operation times, of 14 and 5.5 days, respectively. The EMR performed with specific productivities comparable to batch reactions. However, in the EMR, 220, 40, and 9 times more product per enzymatic unit was produced, for 2′-deoxyadenosine, 2,6-dichloropurine-2′-deoxyribonucleoside, and 6-chloro-2-fluoro-2′-deoxyribonucleoside, respectively. The application of the EMR using freely dissolved enzymes, facilitates a continuous process with integrated biocatalyst separation, which reduces the overall cost of the biocatalyst and enhances the downstream processing of nucleoside production.
Collapse
|
2
|
Il’icheva IA, Polyakov KM, Mikhailov SN. Strained Conformations of Nucleosides in Active Sites of Nucleoside Phosphorylases. Biomolecules 2020; 10:E552. [PMID: 32260512 PMCID: PMC7226091 DOI: 10.3390/biom10040552] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Revised: 03/26/2020] [Accepted: 04/01/2020] [Indexed: 11/28/2022] Open
Abstract
Nucleoside phosphorylases catalyze the reversible phosphorolysis of nucleosides to heterocyclic bases, giving α-d-ribose-1-phosphate or α-d-2-deoxyribose-1-phosphate. These enzymes are involved in salvage pathways of nucleoside biosynthesis. The level of these enzymes is often elevated in tumors, which can be used as a marker for cancer diagnosis. This review presents the analysis of conformations of nucleosides and their analogues in complexes with nucleoside phosphorylases of the first (NP-1) family, which includes hexameric and trimeric purine nucleoside phosphorylases (EC 2.4.2.1), hexameric and trimeric 5'-deoxy-5'-methylthioadenosine phosphorylases (EC 2.4.2.28), and uridine phosphorylases (EC 2.4.2.3). Nucleosides adopt similar conformations in complexes, with these conformations being significantly different from those of free nucleosides. In complexes, pentofuranose rings of all nucleosides are at the W region of the pseudorotation cycle that corresponds to the energy barrier to the N↔S interconversion. In most of the complexes, the orientation of the bases with respect to the ribose is in the high-syn region in the immediate vicinity of the barrier to syn ↔ anti transitions. Such conformations of nucleosides in complexes are unfavorable when compared to free nucleosides and they are stabilized by interactions with the enzyme. The sulfate (or phosphate) ion in the active site of the complexes influences the conformation of the furanose ring. The binding of nucleosides in strained conformations is a characteristic feature of the enzyme-substrate complex formation for this enzyme group.
Collapse
Affiliation(s)
| | | | - Sergey N. Mikhailov
- Engelhardt Institute of Molecular Biology, Russian Academy of Sciences, Vavilov Str. 32, 119991 Moscow, Russia; (I.A.I.); (K.M.P.)
| |
Collapse
|
3
|
Timofeev VI, Zhukhlistova NE, Abramchik YA, Muravieva TI, Esipov RS, Kuranova IP. Crystal structure of Escherichia coli purine nucleoside phosphorylase complexed with acyclovir. Acta Crystallogr F Struct Biol Commun 2018; 74:402-409. [PMID: 29969103 PMCID: PMC6038453 DOI: 10.1107/s2053230x18008087] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 05/31/2018] [Indexed: 11/10/2022] Open
Abstract
Escherichia coli purine nucleoside phosphorylase (PNP), which catalyzes the reversible phosphorolysis of purine ribonucleosides, belongs to the family I hexameric PNPs. Owing to their key role in the purine salvage pathway, PNPs are attractive targets for drug design against some pathogens. Acyclovir (ACV) is an acyclic derivative of the PNP substrate guanosine and is used as an antiviral drug for the treatment of some human viral infections. The crystalline complex of E. coli PNP with acyclovir was prepared by co-crystallization in microgravity using counter-diffusion through a gel layer in a capillary. The structure of the E. coli PNP-ACV complex was solved at 2.32 Å resolution using the molecular-replacement method. The ACV molecule is observed in two conformations and sulfate ions were located in both the nucleoside-binding and phosphate-binding pockets of the enzyme. A comparison with the complexes of other hexameric and trimeric PNPs with ACV shows the similarity in acyclovir binding by these enzymes.
Collapse
Affiliation(s)
- Vladimir I. Timofeev
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre ‘Crystallography and Photonics’ of Russian Academy of Sciences, Leninsky Prospekt 59, Moscow 119333, Russian Federation
- Kurchatov Complex of NBICS-Technologies, National Research Center ‘Kurchatov Institute’, Akad. Kurchatova Square 1, Moscow 123182, Russian Federation
| | - Nadezhda E. Zhukhlistova
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre ‘Crystallography and Photonics’ of Russian Academy of Sciences, Leninsky Prospekt 59, Moscow 119333, Russian Federation
| | - Yuliya A. Abramchik
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Tatiana I. Muravieva
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Roman S. Esipov
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Inna P. Kuranova
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre ‘Crystallography and Photonics’ of Russian Academy of Sciences, Leninsky Prospekt 59, Moscow 119333, Russian Federation
- Kurchatov Complex of NBICS-Technologies, National Research Center ‘Kurchatov Institute’, Akad. Kurchatova Square 1, Moscow 123182, Russian Federation
| |
Collapse
|
4
|
Timofeev VI, Zhukhlistova NE, Abramchik YA, Fateev II, Kostromina MA, Muravieva TI, Esipov RS, Kuranova IP. Crystal structure of Escherichia coli purine nucleoside phosphorylase in complex with 7-deazahypoxanthine. Acta Crystallogr F Struct Biol Commun 2018; 74:355-362. [PMID: 29870020 PMCID: PMC5987744 DOI: 10.1107/s2053230x18006337] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 04/25/2018] [Indexed: 11/10/2022] Open
Abstract
Purine nucleoside phosphorylases (EC 2.4.2.1; PNPs) reversibly catalyze the phosphorolytic cleavage of glycosidic bonds in purine nucleosides to generate ribose 1-phosphate and a free purine base, and are key enzymes in the salvage pathway of purine biosynthesis. They also catalyze the transfer of pentosyl groups between purine bases (the transglycosylation reaction) and are widely used for the synthesis of biologically important analogues of natural nucleosides, including a number of anticancer and antiviral drugs. Potent inhibitors of PNPs are used in chemotherapeutic applications. The detailed study of the binding of purine bases and their derivatives in the active site of PNPs is of particular interest in order to understand the mechanism of enzyme action and for the development of new enzyme inhibitors. Here, it is shown that 7-deazahypoxanthine (7DHX) is a noncompetitive inhibitor of the phosphorolysis of inosine by recombinant Escherichia coli PNP (EcPNP) with an inhibition constant Ki of 0.13 mM. A crystal of EcPNP in complex with 7DHX was obtained in microgravity by the counter-diffusion technique and the three-dimensional structure of the EcPNP-7DHX complex was solved by molecular replacement at 2.51 Å resolution using an X-ray data set collected at the SPring-8 synchrotron-radiation facility, Japan. The crystals belonged to space group P6122, with unit-cell parameters a = b = 120.370, c = 238.971 Å, and contained three subunits of the hexameric enzyme molecule in the asymmetric unit. The 7DHX molecule was located with full occupancy in the active site of each of the three crystallographically independent enzyme subunits. The position of 7DHX overlapped with the positions occupied by purine bases in similar PNP complexes. However, the orientation of the 7DHX molecule differs from those of other bases: it is rotated by ∼180° relative to other bases. The peculiarities of the arrangement of 7DHX in the EcPNP active site are discussed.
Collapse
Affiliation(s)
- Vladimir I. Timofeev
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre ‘Crystallography and Photonics’ of Russian Academy of Sciences, Leninsky Prospekt 59, Moscow 119333, Russian Federation
- Kurchatov Complex of NBICS-Technologies, National Research Center ‘Kurchatov Institute’, Akad. Kurchatova Square 1, Moscow 123182, Russian Federation
| | - Nadezhda E. Zhukhlistova
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre ‘Crystallography and Photonics’ of Russian Academy of Sciences, Leninsky Prospekt 59, Moscow 119333, Russian Federation
| | - Yuliya A. Abramchik
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Ilya I. Fateev
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Maria A. Kostromina
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Tatiana I. Muravieva
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Roman S. Esipov
- Shemyakin–Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russian Federation
| | - Inna P. Kuranova
- Shubnikov Institute of Crystallography, Federal Scientific Research Centre ‘Crystallography and Photonics’ of Russian Academy of Sciences, Leninsky Prospekt 59, Moscow 119333, Russian Federation
- Kurchatov Complex of NBICS-Technologies, National Research Center ‘Kurchatov Institute’, Akad. Kurchatova Square 1, Moscow 123182, Russian Federation
| |
Collapse
|
5
|
Mordkovich NN, Safonova TN, Antipov AN, Manuvera VA, Polyakov KM, Okorokova NA, Veiko VP. Study of Structural-Functional Organization of Nucleoside Phosphorylases of Gammaproteobacteria. Special Aspects of Functioning of Uridine Phosphorylase Phosphate-Binding Site. APPL BIOCHEM MICRO+ 2018. [DOI: 10.1134/s0003683818010064] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
6
|
Štefanić Z, Mikleušević G, Luić M, Bzowska A, Leščić Ašler I. Structural characterization of purine nucleoside phosphorylase from human pathogen Helicobacter pylori. Int J Biol Macromol 2017; 101:518-526. [PMID: 28336275 DOI: 10.1016/j.ijbiomac.2017.03.101] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Revised: 03/17/2017] [Accepted: 03/18/2017] [Indexed: 10/19/2022]
Abstract
Microaerophilic bacterium Helicobacer pylori is a well known human pathogen involved in the development of many diseases. Due to the evergrowing infection rate and increase of H. pylori antibiotic resistence, it is of utmost importance to find a new way to attack and eradicate H. pylori. The purine metabolism in H. pylori is solely dependant on the salvage pathway and one of the key enzymes in this pathway is purine nucleoside phosphorylase (PNP). In this timely context, we report here the basic biochemical and structural characterization of recombinant PNP from the H. pylori clinical isolate expressed in Escherichia coli. Structure of H. pylori PNP is typical for high molecular mass PNPs. However, its activity towards adenosine is very low, thus resembling more that of low molecular mass PNPs. Understanding the molecular mechanism of this key enzyme may lead to the development of new drug strategies and help in the eradication of H. pylori.
Collapse
Affiliation(s)
- Zoran Štefanić
- Division of Physical Chemistry, Ruđer Bošković Institute, POB 180, Bijenička cesta 54, HR-10002 Zagreb, Croatia
| | - Goran Mikleušević
- Division of Physical Chemistry, Ruđer Bošković Institute, POB 180, Bijenička cesta 54, HR-10002 Zagreb, Croatia
| | - Marija Luić
- Division of Physical Chemistry, Ruđer Bošković Institute, POB 180, Bijenička cesta 54, HR-10002 Zagreb, Croatia
| | - Agnieszka Bzowska
- Division of Biophysics, Institute of Experimental Physics, Faculty of Physics, University of Warsaw, Żwirki i Wigury 93, 02-089 Warsaw, Poland
| | - Ivana Leščić Ašler
- Division of Physical Chemistry, Ruđer Bošković Institute, POB 180, Bijenička cesta 54, HR-10002 Zagreb, Croatia.
| |
Collapse
|
7
|
Timofeev VI, Abramchik YA, Zhukhlistova NE, Muravieva TI, Esipov RS, Kuranova IP. Three-dimensional structure of E. Coli purine nucleoside phosphorylase at 0.99 Å resolution. CRYSTALLOGR REP+ 2016. [DOI: 10.1134/s1063774516020292] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
8
|
Youn HS, Kim TG, Kim MK, Kang GB, Kang JY, Lee JG, An JY, Park KR, Lee Y, Im YJ, Lee JH, Eom SH. Structural Insights into the Quaternary Catalytic Mechanism of Hexameric Human Quinolinate Phosphoribosyltransferase, a Key Enzyme in de novo NAD Biosynthesis. Sci Rep 2016; 6:19681. [PMID: 26805589 PMCID: PMC4726147 DOI: 10.1038/srep19681] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2015] [Accepted: 12/14/2015] [Indexed: 11/09/2022] Open
Abstract
Quinolinate phosphoribosyltransferase (QPRT) catalyses the production of nicotinic
acid mononucleotide, a precursor of de novo biosynthesis of the ubiquitous
coenzyme nicotinamide adenine dinucleotide. QPRT is also essential for maintaining
the homeostasis of quinolinic acid in the brain, a possible neurotoxin causing
various neurodegenerative diseases. Although QPRT has been extensively analysed, the
molecular basis of the reaction catalysed by human QPRT remains unclear. Here, we
present the crystal structures of hexameric human QPRT in the apo form and its
complexes with reactant or product. We found that the interaction between dimeric
subunits was dramatically altered during the reaction process by conformational
changes of two flexible loops in the active site at the dimer-dimer interface. In
addition, the N-terminal short helix α1 was identified as a critical
hexamer stabilizer. The structural features, size distribution, heat aggregation and
ITC studies of the full-length enzyme and the enzyme lacking helix α1
strongly suggest that human QPRT acts as a hexamer for cooperative reactant binding
via three dimeric subunits and maintaining stability. Based on our comparison of
human QPRT structures in the apo and complex forms, we propose a drug design
strategy targeting malignant glioma.
Collapse
Affiliation(s)
- Hyung-Seop Youn
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Tae Gyun Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Mun-Kyoung Kim
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Gil Bu Kang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Jung Youn Kang
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Jung-Gyu Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Jun Yop An
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Kyoung Ryoung Park
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Youngjin Lee
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| | - Young Jun Im
- College of Pharmacy, Chonnam National University, Gwangju 500-757, South Korea
| | - Jun Hyuck Lee
- Division of Polar Life Sciences, Korea Polar Research Institute, Incheon 406-840, South Korea.,Department of Polar Sciences, Korea University of Science and Technology, Incheon 406-840, South Korea
| | - Soo Hyun Eom
- School of Life Sciences, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Steitz Center for Structural Biology, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea.,Department of Chemistry, Gwangju Institute of Science and Technology, Gwangju 500-712, South Korea
| |
Collapse
|
9
|
Giuliani P, Zuccarini M, Buccella S, Rossini M, D'Alimonte I, Ciccarelli R, Marzo M, Marzo A, Di Iorio P, Caciagli F. Development of a new HPLC method using fluorescence detection without derivatization for determining purine nucleoside phosphorylase activity in human plasma. J Chromatogr B Analyt Technol Biomed Life Sci 2015; 1009-1010:114-21. [PMID: 26720700 DOI: 10.1016/j.jchromb.2015.12.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2015] [Revised: 12/02/2015] [Accepted: 12/07/2015] [Indexed: 01/07/2023]
Abstract
Purine nucleoside phosphorylase (PNP) activity is involved in cell survival and function, since PNP is a key enzyme in the purine metabolic pathway where it catalyzes the phosphorolysis of the nucleosides to the corresponding nucleobases. Its dysfunction has been found in relevant pathological conditions (such as inflammation and cancer), so the detection of PNP activity in plasma could represent an attractive marker for early diagnosis or assessment of disease progression. Thus the aim of this study was to develop a simple, fast and sensitive HPLC method for the determination of PNP activity in plasma. The separation was achieved on a Phenomenex Kinetex PFP column using 0.1% formic acid in water and methanol as mobile phases in gradient elution mode at a flow rate of 1ml/min and purine compounds were detected using UV absorption and fluorescence. The analysis was fast since the run was achieved within 13min. This method improved the separation of the different purines, allowing the UV-based quantification of the natural PNP substrates (inosine and guanosine) or products (hypoxanthine and guanine) and its subsequent metabolic products (xanthine and uric acid) with a good precision and accuracy. The most interesting innovation is the simultaneous use of a fluorescence detector (excitation/emission wavelength of 260/375nm) that allowed the quantification of guanosine and guanine without derivatization. Compared with UV, the fluorescence detection improved the sensitivity for guanine detection by about 10-fold and abolished almost completely the baseline noise due to the presence of plasma in the enzymatic reaction mixture. Thus, the validated method allowed an excellent evaluation of PNP activity in plasma which could be useful as an indicator of several pathological conditions.
Collapse
Affiliation(s)
- Patricia Giuliani
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Mariachiara Zuccarini
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Silvana Buccella
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Margherita Rossini
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Iolanda D'Alimonte
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Renata Ciccarelli
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Matteo Marzo
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Antonio Marzo
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Patrizia Di Iorio
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| | - Francesco Caciagli
- Department of Medical, Oral and Biotechnological Sciences, Laboratory of Pharmacology and Toxicology, University of Chieti-Pescara, Via dei Vestini 29, 66013 Chieti, Italy.
| |
Collapse
|
10
|
Purine nucleoside phosphorylase activity decline is linked to the decay of the trimeric form of the enzyme. Arch Biochem Biophys 2014; 549:40-8. [DOI: 10.1016/j.abb.2014.03.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Revised: 03/17/2014] [Accepted: 03/19/2014] [Indexed: 10/25/2022]
|