1
|
de Dios SMR, Hass JL, Graham DL, Kumar N, Antony AE, Morton MD, Berkowitz DB. Information-Rich, Dual-Function 13C/ 2H-Isotopic Crosstalk NMR Assay for Human Serine Racemase (hSR) Provides a PLP-Enzyme "Partitioning Fingerprint" and Reveals Disparate Chemotypes for hSR Inhibition. J Am Chem Soc 2023; 145:3158-3174. [PMID: 36696670 PMCID: PMC11103274 DOI: 10.1021/jacs.2c12774] [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] [Indexed: 01/27/2023]
Abstract
The first dual-function assay for human serine racemase (hSR), the only bona fide racemase in human biology, is reported. The hSR racemization function is essential for neuronal signaling, as the product, d-serine (d-Ser), is a potent N-methyl d-aspartate (NMDA) coagonist, important for learning and memory, with dysfunctional d-Ser-signaling being observed in some neuronal disorders. The second hSR function is β-elimination and gives pyruvate; this activity is elevated in colorectal cancer. This new NMR-based assay allows one to monitor both α-proton-exchange chemistry and β-elimination using only the native l-Ser substrate and hSR and is the most sensitive such assay. The assay judiciously employs segregated dual 13C-labeling and 13C/2H crosstalk, exploiting both the splitting and shielding effects of deuterium. The assay is deployed to screen a 1020-compound library and identifies an indolo-chroman-2,4-dione inhibitor family that displays allosteric site binding behavior (noncompetitive inhibition vs l-Ser substrate; competitive inhibition vs adenosine 5'-triphosphate (ATP)). This assay also reveals important mechanistic information for hSR; namely, that H/D exchange is ∼13-fold faster than racemization, implying that K56 protonates the carbanionic intermediate on the si-face much faster than does S84 on the re-face. Moreover, the 13C NMR peak pattern seen is suggestive of internal return, pointing to K56 as the likely enamine-protonating residue for β-elimination. The 13C/2H-isotopic crosstalk assay has also been applied to the enzyme tryptophan synthase and reveals a dramatically different partition ratio in this active site (β-replacement: si-face protonation ∼6:1 vs β-elimination: si-face protonation ∼1:3.6 for hSR), highlighting the value of this approach for fingerprinting the pyridoxal phosphate (PLP) enzyme mechanism.
Collapse
Affiliation(s)
| | | | | | - Nivesh Kumar
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588 USA
| | - Aina E. Antony
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588 USA
| | - Martha D. Morton
- Department of Chemistry, University of Nebraska, Lincoln, NE 68588 USA
| | | |
Collapse
|
2
|
Human Serine Racemase Weakly Binds the Third PDZ Domain of PSD-95. Int J Mol Sci 2022; 23:ijms23094959. [PMID: 35563349 PMCID: PMC9105370 DOI: 10.3390/ijms23094959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 04/13/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022] Open
Abstract
Human serine racemase (hSR) is a pyridoxal-5'-phosphate (PLP)-dependent dimer that catalyzes the formation of D-serine from L-serine, as well as the dehydration of both L- and D-serine to pyruvate and ammonia. As D-serine is a co-agonist of N-methyl-D-aspartate receptors (NMDARs), hSR is a key enzyme in glutamatergic neurotransmission. hSR activity is finely regulated by Mg2+, ATP, post-translational modifications, and the interaction with protein partners. In particular, the C-terminus of murine SR binds the third PDZ domain (PDZ3) of postsynaptic density protein 95 (PSD-95), a member of the membrane-associated guanylate kinase (MAGUK) family involved in the trafficking and localization of glutamate receptors. The structural details of the interaction and the stability of the complex have not been elucidated yet. We evaluated the binding of recombinant human PSD-95 PDZ3 to hSR by glutaraldehyde cross-linking, pull-down assays, isothermal titration calorimetry, nuclear magnetic resonance, and enzymatic assays. Overall, a weak interaction was observed, confirming the binding for the human orthologs but supporting the hypothesis that a third protein partner (i.e., stargazin) is required for the regulation of hSR activity by PSD-95 and to stabilize their interaction.
Collapse
|
3
|
Koulouris CR, Gardiner SE, Harris TK, Elvers KT, Mark Roe S, Gillespie JA, Ward SE, Grubisha O, Nicholls RA, Atack JR, Bax BD. Tyrosine 121 moves revealing a ligandable pocket that couples catalysis to ATP-binding in serine racemase. Commun Biol 2022; 5:346. [PMID: 35410329 PMCID: PMC9001717 DOI: 10.1038/s42003-022-03264-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Accepted: 03/14/2022] [Indexed: 11/23/2022] Open
Abstract
Human serine racemase (hSR) catalyses racemisation of L-serine to D-serine, the latter of which is a co-agonist of the NMDA subtype of glutamate receptors that are important in synaptic plasticity, learning and memory. In a 'closed' hSR structure containing the allosteric activator ATP, the inhibitor malonate is enclosed between the large and small domains while ATP is distal to the active site, residing at the dimer interface with the Tyr121 hydroxyl group contacting the α-phosphate of ATP. In contrast, in 'open' hSR structures, Tyr121 sits in the core of the small domain with its hydroxyl contacting the key catalytic residue Ser84. The ability to regulate SR activity by flipping Tyr121 from the core of the small domain to the dimer interface appears to have evolved in animals with a CNS. Multiple X-ray crystallographic enzyme-fragment structures show Tyr121 flipped out of its pocket in the core of the small domain. Data suggest that this ligandable pocket could be targeted by molecules that inhibit enzyme activity.
Collapse
Affiliation(s)
- Chloe R Koulouris
- Sussex Drug Discovery Centre, University of Sussex, Brighton, BN1 9QG, UK
| | - Sian E Gardiner
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Tessa K Harris
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Karen T Elvers
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - S Mark Roe
- Department of Biochemistry and Biomedicine, University of Sussex, Brighton, BN1 9QJ, UK
| | - Jason A Gillespie
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Simon E Ward
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Olivera Grubisha
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK
| | - Robert A Nicholls
- MRC Laboratory of Molecular Biology, Francis Crick Ave, CB2 0QH, Cambridge, UK
| | - John R Atack
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK.
| | - Benjamin D Bax
- Medicines Discovery Institute, Cardiff University, Cardiff, CF10 3AT, UK.
| |
Collapse
|
4
|
Marchesani F, Gianquinto E, Autiero I, Michielon A, Campanini B, Faggiano S, Bettati S, Mozzarelli A, Spyrakis F, Bruno S. The allosteric interplay between S-nitrosylation and glycine binding controls the activity of human serine racemase. FEBS J 2020; 288:3034-3054. [PMID: 33249721 DOI: 10.1111/febs.15645] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/06/2020] [Accepted: 11/09/2020] [Indexed: 12/15/2022]
Abstract
Human serine racemase (hSR) catalyzes the biosynthesis of D-serine, an obligatory co-agonist of the NMDA receptors. It was previously found that the reversible S-nitrosylation of Cys113 reduces hSR activity. Here, we show by site-directed mutagenesis, fluorescence spectroscopy, mass spectrometry, and molecular dynamics that S-nitrosylation stabilizes an open, less-active conformation of the enzyme. The reaction of hSR with either NO or nitroso donors is conformation-dependent and occurs only in the conformation stabilized by the allosteric effector ATP, in which the ε-amino group of Lys114 acts as a base toward the thiol group of Cys113. In the closed conformation stabilized by glycine-an active-site ligand of hSR-the side chain of Lys114 moves away from that of Cys113, while the carboxyl side-chain group of Asp318 moves significantly closer, increasing the thiol pKa and preventing the reaction. We conclude that ATP binding, glycine binding, and S-nitrosylation constitute a three-way regulation mechanism for the tight control of hSR activity. We also show that Cys113 undergoes H2 O2 -mediated oxidation, with loss of enzyme activity, a reaction also dependent on hSR conformation.
Collapse
Affiliation(s)
- Francesco Marchesani
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Italy
| | - Eleonora Gianquinto
- Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Italy
| | - Ida Autiero
- Molecular Horizon Srl, Bettona, PG, Italy.,Consiglio Nazionale delle Ricerche, Istituto di Biostrutture e Bioimmagini, Napoli, Italy
| | - Annalisa Michielon
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Italy
| | - Barbara Campanini
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Italy
| | - Serena Faggiano
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Italy.,Consiglio Nazionale delle Ricerche, Istituto di Biofisica, Pisa, Italy
| | - Stefano Bettati
- Consiglio Nazionale delle Ricerche, Istituto di Biofisica, Pisa, Italy.,Dipartimento di Medicina e Chirurgia, Parma, Italy
| | - Andrea Mozzarelli
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Italy.,Consiglio Nazionale delle Ricerche, Istituto di Biofisica, Pisa, Italy
| | - Francesca Spyrakis
- Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, Italy
| | - Stefano Bruno
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università degli Studi di Parma, Italy
| |
Collapse
|
5
|
Accelerated identification of serine racemase inhibitor from Centella asiatica. Sci Rep 2020; 10:4640. [PMID: 32170206 PMCID: PMC7070078 DOI: 10.1038/s41598-020-61494-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2017] [Accepted: 02/25/2020] [Indexed: 01/12/2023] Open
Abstract
Serine racemase (SR) converts the free form of L-serine into D-serine (DS) in the mammalian brain. The DS functions as a co-agonist of N-methyl D-aspartate (NMDA) receptor. The over- activation of NMDA receptor leads to many neurological disorders like stroke, amyotrophic lateral sclerosis, Alzheimer’s disease and an effective inhibitor of SR could be a corrective method for the receptor over-activation. We report for the first time here a rapid way of purifying and identifying an inhibitor from medicinal plants known to have the neuro-protective effect. We have purified SR inhibitor from the methanolic extract of Centella asiatica by affinity method. High resolution mass spectrometry and infrared spectroscopy were used to identify the ligand to be madecassoside. We have shown the madecassoside binding in silico and its inhibition of recombinant human serine racemase in vitro and ex vivo.
Collapse
|
6
|
Koulouris CR, Bax BD, Atack JR, Roe SM. Conformational flexibility within the small domain of human serine racemase. Acta Crystallogr F Struct Biol Commun 2020; 76:65-73. [PMID: 32039887 PMCID: PMC7010357 DOI: 10.1107/s2053230x20001193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Accepted: 01/28/2020] [Indexed: 01/28/2023] Open
Abstract
Serine racemase (SR) is a pyridoxal 5'-phosphate (PLP)-containing enzyme that converts L-serine to D-serine, an endogenous co-agonist for the N-methyl-D-aspartate receptor (NMDAR) subtype of glutamate ion channels. SR regulates D-serine levels by the reversible racemization of L-serine to D-serine, as well as the catabolism of serine by α,β-elimination to produce pyruvate. The modulation of SR activity is therefore an attractive therapeutic approach to disorders associated with abnormal glutamatergic signalling since it allows an indirect modulation of NMDAR function. In the present study, a 1.89 Å resolution crystal structure of the human SR holoenzyme (including the PLP cofactor) with four subunits in the asymmetric unit is described. Comparison of this new structure with the crystal structure of human SR with malonate (PDB entry 3l6b) shows an interdomain cleft that is open in the holo structure but which disappears when the inhibitor malonate binds and is enclosed. This is owing to a shift of the small domain (residues 78-155) in human SR similar to that previously described for the rat enzyme. This domain movement is accompanied by changes within the twist of the central four-stranded β-sheet of the small domain, including changes in the φ-ψ angles of all three residues in the C-terminal β-strand (residues 149-151). In the malonate-bound structure, Ser84 (a catalytic residue) points its side chain at the malonate and is preceded by a six-residue β-strand (residues 78-83), but in the holoenzyme the β-strand is only four residues (78-81) and His82 has φ-ψ values in the α-helical region of the Ramachandran plot. These data therefore represent a crystallographic platform that enables the structure-guided design of small-molecule modulators for this important but to date undrugged target.
Collapse
Affiliation(s)
- Chloe R. Koulouris
- Sussex Drug Discovery Centre, University of Sussex, Falmer, Brighton BN1 9QG, England
| | - Benjamin D. Bax
- Medicines Discovery Institute, School of Biosciences, University of Cardiff, Park Place, Cardiff CF10 3AT, Wales
| | - John R. Atack
- Medicines Discovery Institute, School of Biosciences, University of Cardiff, Park Place, Cardiff CF10 3AT, Wales
| | - S. Mark Roe
- Department of Biochemistry and Biomedicine, School of Life Sciences, University of Sussex, Falmer, Brighton BN1 9QJ, England
| |
Collapse
|
7
|
Raboni S, Marchetti M, Faggiano S, Campanini B, Bruno S, Marchesani F, Margiotta M, Mozzarelli A. The Energy Landscape of Human Serine Racemase. Front Mol Biosci 2019; 5:112. [PMID: 30687716 PMCID: PMC6333871 DOI: 10.3389/fmolb.2018.00112] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2018] [Accepted: 11/26/2018] [Indexed: 12/17/2022] Open
Abstract
Human serine racemase is a pyridoxal 5′-phosphate (PLP)-dependent dimeric enzyme that catalyzes the reversible racemization of L-serine and D-serine and their dehydration to pyruvate and ammonia. As D-serine is the co-agonist of the N-methyl-D-aspartate receptors for glutamate, the most abundant excitatory neurotransmitter in the brain, the structure, dynamics, function, regulation and cellular localization of serine racemase have been investigated in detail. Serine racemase belongs to the fold-type II of the PLP-dependent enzyme family and structural models from several orthologs are available. The comparison of structures of serine racemase co-crystallized with or without ligands indicates the presence of at least one open and one closed conformation, suggesting that conformational flexibility plays a relevant role in enzyme regulation. ATP, Mg2+, Ca2+, anions, NADH and protein interactors, as well as the post-translational modifications nitrosylation and phosphorylation, finely tune the racemase and dehydratase activities and their relative reaction rates. Further information on serine racemase structure and dynamics resulted from the search for inhibitors with potential therapeutic applications. The cumulative knowledge on human serine racemase allowed obtaining insights into its conformational landscape and into the mechanisms of cross-talk between the effector binding sites and the active site.
Collapse
Affiliation(s)
- Samanta Raboni
- Department of Food and Drug, University of Parma, Parma, Italy
| | | | - Serena Faggiano
- Department of Food and Drug, University of Parma, Parma, Italy.,Institute of Biophysics, National Research Council, Pisa, Italy
| | | | - Stefano Bruno
- Department of Food and Drug, University of Parma, Parma, Italy
| | | | | | - Andrea Mozzarelli
- Department of Food and Drug, University of Parma, Parma, Italy.,Institute of Biophysics, National Research Council, Pisa, Italy.,National Institute of Biostructures and Biosystems, Rome, Italy
| |
Collapse
|
8
|
Glutamine 89 is a key residue in the allosteric modulation of human serine racemase activity by ATP. Sci Rep 2018; 8:9016. [PMID: 29899358 PMCID: PMC5998037 DOI: 10.1038/s41598-018-27227-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 05/25/2018] [Indexed: 11/17/2022] Open
Abstract
Serine racemase (SR) catalyses two reactions: the reversible racemisation of L-serine and the irreversible dehydration of L- and D-serine to pyruvate and ammonia. SRs are evolutionarily related to serine dehydratases (SDH) and degradative threonine deaminases (TdcB). Most SRs and TdcBs – but not SDHs – are regulated by nucleotides. SR binds ATP cooperatively and the nucleotide allosterically stimulates the serine dehydratase activity of the enzyme. A H-bond network comprising five residues (T52, N86, Q89, E283 and N316) and water molecules connects the active site with the ATP-binding site. Conservation analysis points to Q89 as a key residue for the allosteric communication, since its mutation to either Met or Ala is linked to the loss of control of activity by nucleotides. We verified this hypothesis by introducing the Q89M and Q89A point mutations in the human SR sequence. The allosteric communication between the active site and the allosteric site in both mutants is almost completely abolished. Indeed, the stimulation of the dehydratase activity by ATP is severely diminished and the binding of the nucleotide is no more cooperative. Ancestral state reconstruction suggests that the allosteric control by nucleotides established early in SR evolution and has been maintained in most eukaryotic lineages.
Collapse
|
9
|
Takahara S, Nakagawa K, Uchiyama T, Yoshida T, Matsumoto K, Kawasumi Y, Mizuguchi M, Obita T, Watanabe Y, Hayakawa D, Gouda H, Mori H, Toyooka N. Design, synthesis, and evaluation of novel inhibitors for wild-type human serine racemase. Bioorg Med Chem Lett 2018; 28:441-445. [DOI: 10.1016/j.bmcl.2017.12.021] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Revised: 12/01/2017] [Accepted: 12/10/2017] [Indexed: 01/23/2023]
|
10
|
Marchesani F, Bruno S, Paredi G, Raboni S, Campanini B, Mozzarelli A. Human serine racemase is nitrosylated at multiple sites. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:813-821. [PMID: 29410194 DOI: 10.1016/j.bbapap.2018.01.009] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/30/2017] [Revised: 01/18/2018] [Accepted: 01/29/2018] [Indexed: 11/26/2022]
Abstract
Serine racemase is a pyridoxal 5'‑phosphate dependent enzyme responsible for the synthesis of d‑serine, a neuromodulator of the NMDA receptors. Its activity is modulated by several ligands, including ATP, divalent cations and protein interactors. The murine orthologue is inhibited by S-nitrosylation at Cys113, a residue adjacent to the ATP binding site. We found that the time course of inhibition of human serine racemase by S-nitrosylation is markedly biphasic, with a fast phase associated with the reaction of Cys113. Unlike the murine enzyme, two additional cysteine residues, Cys269, unique to the human orthologue, and Cys128 were also recognized as S-nitrosylation sites through mass spectrometry and site-directed mutagenesis. The effect of S-nitrosylation on the fluorescence of tryptophan residues and on that of the pyridoxal phosphate cofactor indicated that S-nitrosylation produces a partial interruption of the cross-talk between the ATP binding site and the active site. Overall, it appears that the inhibition results from a conformational change rather than the direct displacement of ATP.
Collapse
Affiliation(s)
- Francesco Marchesani
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy
| | - Stefano Bruno
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy.
| | - Gianluca Paredi
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy
| | - Samanta Raboni
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy
| | - Barbara Campanini
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy
| | - Andrea Mozzarelli
- Dipartimento di Scienze degli Alimenti e del Farmaco, Università di Parma, Parma, Italy; Istituto di Biofisica, Consiglio Nazionale delle Ricerche, Pisa, Italy
| |
Collapse
|
11
|
Mori H, Wada R, Takahara S, Horino Y, Izumi H, Ishimoto T, Yoshida T, Mizuguchi M, Obita T, Gouda H, Hirono S, Toyooka N. A novel serine racemase inhibitor suppresses neuronal over-activation in vivo. Bioorg Med Chem 2017; 25:3736-3745. [PMID: 28533113 DOI: 10.1016/j.bmc.2017.05.011] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2017] [Revised: 05/02/2017] [Accepted: 05/05/2017] [Indexed: 12/11/2022]
Abstract
Serine racemase (SRR) is an enzyme that produces d-serine from l-serine. d-Serine acts as an endogenous coagonist of NMDA-type glutamate receptors (NMDARs), which regulate many physiological functions. Over-activation of NMDARs induces excitotoxicity, which is observed in many neurodegenerative disorders and epilepsy states. In our previous works on the generation of SRR gene knockout (Srr-KO) mice and its protective effects against NMDA- and Aβ peptide-induced neurodegeneration, we hypothesized that the regulation of NMDARs' over-activation by inhibition of SRR activity is one such therapeutic strategy to combat these disease states. In the previous study, we performed in silico screening to identify four compounds with inhibitory activities against recombinant SRR. Here, we synthesized 21 derivatives of candidate 1, one of four hit compounds, and performed screening by in vitro evaluations. The derivative 13J showed a significantly lower IC50 value in vitro, and suppressed neuronal over-activation in vivo.
Collapse
Affiliation(s)
- Hisashi Mori
- Graduate School of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan; Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Ryogo Wada
- Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan
| | - Satoyuki Takahara
- Graduate School of Innovative Life Science, University of Toyama, Toyama 930-8555, Japan
| | - Yoshikazu Horino
- Graduate School of Innovative Life Science, University of Toyama, Toyama 930-8555, Japan
| | - Hironori Izumi
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Tetsuya Ishimoto
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Tomoyuki Yoshida
- Graduate School of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan; Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Mineyuki Mizuguchi
- Graduate School of Innovative Life Science, University of Toyama, Toyama 930-0194, Japan; Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Takayuki Obita
- Graduate School of Medicine and Pharmaceutical Sciences, University of Toyama, Toyama 930-0194, Japan
| | - Hiroaki Gouda
- School of Pharmacy, Showa University, Tokyo 142-8555, Japan
| | - Shuichi Hirono
- School of Pharmacy, Kitasato University, Tokyo 108-8641, Japan
| | - Naoki Toyooka
- Graduate School of Science and Engineering, University of Toyama, Toyama 930-8555, Japan; Graduate School of Innovative Life Science, University of Toyama, Toyama 930-8555, Japan.
| |
Collapse
|
12
|
Bruno S, Margiotta M, Marchesani F, Paredi G, Orlandi V, Faggiano S, Ronda L, Campanini B, Mozzarelli A. Magnesium and calcium ions differentially affect human serine racemase activity and modulate its quaternary equilibrium toward a tetrameric form. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2017; 1865:381-387. [PMID: 28089597 DOI: 10.1016/j.bbapap.2017.01.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/09/2016] [Revised: 12/21/2016] [Accepted: 01/05/2017] [Indexed: 11/18/2022]
Abstract
Serine racemase is the pyridoxal 5'-phosphate dependent enzyme that catalyzes both production and catabolism of d-serine, a co-agonist of the NMDA glutamate receptors. Mg2+, or, alternatively, Ca2+, activate human serine racemase by binding both at a specific site and - as ATP-metal complexes - at a distinct ATP binding site. We show that Mg2+ and Ca2+ bind at the metal binding site with a 4.5-fold difference in affinity, producing a similar thermal stabilization and partially shifting the dimer-tetramer equilibrium in favour of the latter. The ATP-Ca2+ complex produces a 2-fold lower maximal activation in comparison to the ATP-Mg2+ complex and exhibits a 3-fold higher EC50. The co-presence of ATP and metals further stabilizes the tetramer. In consideration of the cellular concentrations of Mg2+ and Ca2+, even taking into account the fluctuations of the latter, these results point to Mg2+ as the sole physiologically relevant ligand both at the metal binding site and at the ATP binding site. The stabilization of the tetramer by both metals and ATP-metal complexes suggests a quaternary activation mechanism mediated by 5'-phosphonucleotides similar to that observed in the distantly related prokaryotic threonine deaminases. This allosteric mechanism has never been observed before in mammalian fold type II pyridoxal 5'-phosphate dependent enzymes.
Collapse
Affiliation(s)
| | | | | | - Gianluca Paredi
- Interdepartment Center SITEIA.PARMA, University of Parma, Italy
| | | | | | - Luca Ronda
- Department of Neurosciences, University of Parma, Italy
| | | | - Andrea Mozzarelli
- Department of Pharmacy, University of Parma, Italy; Institute of Biophysics, CNR, Pisa, Italy; National Institute of Biostructures and Biomolecules, Rome, Italy
| |
Collapse
|
13
|
Human serine racemase is allosterically modulated by NADH and reduced nicotinamide derivatives. Biochem J 2016; 473:3505-3516. [PMID: 27493223 DOI: 10.1042/bcj20160566] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/04/2016] [Indexed: 11/17/2022]
Abstract
Serine racemase catalyzes both the synthesis and the degradation of d-serine, an obligatory co-agonist of the glutamatergic NMDA receptors. It is allosterically controlled by adenosine triphosphate (ATP), which increases its activity around 7-fold through a co-operative binding mechanism. Serine racemase has been proposed as a drug target for the treatment of several neuropathologies but, so far, the search has been directed only toward the active site, with the identification of a few, low-affinity inhibitors. Following the recent observation that nicotinamide adenine dinucleotide (reduced form) (NADH) inhibits serine racemase, here we show that the inhibition is partial, with an IC50 of 246 ± 63 μM, several-fold higher than NADH intracellular concentrations. At saturating concentrations of NADH, ATP binds with a 2-fold lower affinity and without co-operativity, suggesting ligand competition. NADH also reduces the weak activity of human serine racemase in the absence of ATP, indicating an additional ATP-independent inhibition mechanism. By dissecting the NADH molecule, we discovered that the inhibitory determinant is the N-substituted 1,4-dihydronicotinamide ring. Particularly, the NADH precursor 1,4-dihydronicotinamide mononucleotide exhibited a partial mixed-type inhibition, with a KI of 18 ± 7 μM. Docking simulations suggested that all 1,4-dihydronicotinamide derivatives bind at the interdimeric interface, with the ring positioned in an unoccupied site next to the ATP-binding site. This newly recognized allosteric site might be exploited for the design of high-affinity serine racemase effectors to finely modulate d-serine homeostasis.
Collapse
|
14
|
Dellafiora L, Marchetti M, Spyrakis F, Orlandi V, Campanini B, Cruciani G, Cozzini P, Mozzarelli A. Expanding the chemical space of human serine racemase inhibitors. Bioorg Med Chem Lett 2015; 25:4297-303. [DOI: 10.1016/j.bmcl.2015.07.081] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2015] [Revised: 07/22/2015] [Accepted: 07/24/2015] [Indexed: 01/17/2023]
|
15
|
Beato C, Pecchini C, Cocconcelli C, Campanini B, Marchetti M, Pieroni M, Mozzarelli A, Costantino G. Cyclopropane derivatives as potential human serine racemase inhibitors: unveiling novel insights into a difficult target. J Enzyme Inhib Med Chem 2015; 31:645-52. [PMID: 26133542 DOI: 10.3109/14756366.2015.1057720] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
d-Serine is the co-agonist of NMDA receptors and binds to the so-called glycine site. d-Serine is synthesized by human serine racemase (SR). Over activation of NMDA receptors is involved in many neurodegenerative diseases and, therefore, the inhibition of SR might represent a novel strategy for the treatment of these pathologies. SR is a very difficult target, with only few compounds so far identified exhibiting weak inhibitory activity. This study was aimed at the identification of novel SR inhibitor by mimicking malonic acid, the best-known SR inhibitor, with a cyclopropane scaffold. We developed, synthesized, and tested a series of cyclopropane dicarboxylic acid derivatives, complementing the synthetic effort with molecular docking. We identified few compounds that bind SR in high micromolar range with a lack of significant correlation between experimental and predicted binding affinities. The thorough analysis of the results can be exploited for the development of more potent SR inhibitors.
Collapse
Affiliation(s)
- Claudia Beato
- a Dipartimento di Farmacia , Università degli studi di Parma , Parma , Italy
| | - Chiara Pecchini
- a Dipartimento di Farmacia , Università degli studi di Parma , Parma , Italy
| | - Chiara Cocconcelli
- a Dipartimento di Farmacia , Università degli studi di Parma , Parma , Italy
| | - Barbara Campanini
- a Dipartimento di Farmacia , Università degli studi di Parma , Parma , Italy
| | | | - Marco Pieroni
- a Dipartimento di Farmacia , Università degli studi di Parma , Parma , Italy
| | - Andrea Mozzarelli
- a Dipartimento di Farmacia , Università degli studi di Parma , Parma , Italy .,b Istituto Nazionale Biostrutture e Biosistemi -- Consorzio Interuniversitario , Roma , Italy , and.,c Istituto di Biofisica, CNR , Pisa , Italy
| | - Gabriele Costantino
- a Dipartimento di Farmacia , Università degli studi di Parma , Parma , Italy
| |
Collapse
|
16
|
Marchetti M, Bruno S, Campanini B, Bettati S, Peracchi A, Mozzarelli A. Regulation of human serine racemase activity and dynamics by halides, ATP and malonate. Amino Acids 2014; 47:163-73. [PMID: 25331425 DOI: 10.1007/s00726-014-1856-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2014] [Accepted: 10/09/2014] [Indexed: 02/03/2023]
Abstract
D-Serine is a non-proteinogenic amino acid that acts as a co-agonist of the NMDA receptors in the central nervous system. D-Serine is produced by human serine racemase (hSR), a homodimeric pyridoxal 5'-phosphate (PLP)-dependent enzyme that also catalyzes the physiologically relevant β-elimination of both L- and D-serine to pyruvate and ammonia. After improving the protein purification yield and stability, which had so far limited the biochemical characterization of hSR, we found that the catalytic activity is affected by halides, in the order fluoride > chloride > bromide. On the contrary, iodide elicited a complete inhibition, accompanied by a modulation of the tautomeric equilibrium of the internal aldimine. We also investigated the reciprocal effects of ATP and malonate, an inhibitor that reversibly binds at the active site, 20 Å away from the ATP-binding site. ATP increased ninefold the affinity of hSR for malonate and malonate increased 100-fold that of ATP, confirming an allosteric interaction between the two binding sites. To further investigate this allosteric communication, we probed the active site accessibility by quenching of the coenzyme fluorescence in the absence and presence of ATP. We found that ATP stabilizes a closed conformation of the external aldimine Schiff base, suggesting a possible mechanism for ATP-induced hSR activation.
Collapse
|
17
|
Mori H, Wada R, Li J, Ishimoto T, Mizuguchi M, Obita T, Gouda H, Hirono S, Toyooka N. In silico and pharmacological screenings identify novel serine racemase inhibitors. Bioorg Med Chem Lett 2014; 24:3732-5. [DOI: 10.1016/j.bmcl.2014.07.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 06/25/2014] [Accepted: 07/01/2014] [Indexed: 11/16/2022]
|
18
|
Inhibition of serine and proline racemases by substrate-product analogues. Bioorg Med Chem Lett 2014; 24:390-3. [DOI: 10.1016/j.bmcl.2013.10.061] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2013] [Revised: 10/28/2013] [Accepted: 10/28/2013] [Indexed: 11/16/2022]
|
19
|
Marchetti M, Bruno S, Campanini B, Peracchi A, Mai N, Mozzarelli A. ATP binding to human serine racemase is cooperative and modulated by glycine. FEBS J 2013; 280:5853-63. [PMID: 23992455 DOI: 10.1111/febs.12510] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2013] [Revised: 08/27/2013] [Accepted: 08/29/2013] [Indexed: 11/26/2022]
Abstract
The N-methyl D-aspartate (NMDA) receptors play a key role in excitatory neurotransmission, and control learning, memory and synaptic plasticity. Their activity is modulated by the agonist glutamate and by the co-agonists d-serine and glycine. In the human brain, d-serine is synthesized from l-serine by the dimeric pyridoxal 5'-phosphate-dependent enzyme serine racemase, which also degrades l- and d-serine to pyruvate and ammonia. The dependence of l- and d-serine β-elimination and l-serine racemization activities on ATP concentration was characterized, and was found to be strongly cooperative, with Hill coefficients close to 2 and apparent ATP dissociation constants ranging from 0.22 to 0.41 mm. ATP binding to the holo-enzyme, monitored by the fluorescence changes of the coenzyme, was also determined to be cooperative, with an apparent dissociation constant of 0.24 mm. Glycine, an active-site ligand, increased the serine racemase affinity for ATP by ~ 22-fold, abolishing cooperativity. Conversely, ATP increased the non-cooperative glycine binding 15-fold. These results indicate cross-talk between allosteric and active sites, leading to the stabilization of two alternative protein conformations with ATP affinities of ~ 10 μM and 1.8 mm, as evaluated within the Monod, Wyman and Changeux model. Therefore, intracellular ATP and glycine control d-serine homeostasis, and, indirectly, NMDA receptor activity. Because hyper- and hypo-activation of NMDA receptors are associated with neuropathologies, the development of allosteric drugs modulating serine racemase activity is a promising therapeutic strategy.
Collapse
|
20
|
Controlling reaction specificity in pyridoxal phosphate enzymes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1407-18. [PMID: 21664990 DOI: 10.1016/j.bbapap.2011.05.019] [Citation(s) in RCA: 125] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/18/2011] [Accepted: 05/25/2011] [Indexed: 11/20/2022]
Abstract
Pyridoxal 5'-phosphate enzymes are ubiquitous in the nitrogen metabolism of all organisms. They catalyze a wide variety of reactions including racemization, transamination, decarboxylation, elimination, retro-aldol cleavage, Claisen condensation, and others on substrates containing an amino group, most commonly α-amino acids. The wide variety of reactions catalyzed by PLP enzymes is enabled by the ability of the covalent aldimine intermediate formed between substrate and PLP to stabilize carbanionic intermediates at Cα of the substrate. This review attempts to summarize the mechanisms by which reaction specificity can be achieved in PLP enzymes by focusing on three aspects of these reactions: stereoelectronic effects, protonation state of the external aldimine intermediate, and interaction of the carbanionic intermediate with the protein side chains present in the active site. This article is part of a Special Issue entitled: Pyridoxal Phosphate Enzymology.
Collapse
|
21
|
Wilson BA, Wang H, Nacev BA, Mease RC, Liu JO, Pomper MG, Isaacs WB. High-throughput screen identifies novel inhibitors of cancer biomarker α-methylacyl coenzyme A racemase (AMACR/P504S). Mol Cancer Ther 2011; 10:825-38. [PMID: 21441411 PMCID: PMC3423201 DOI: 10.1158/1535-7163.mct-10-0902] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
α-methylacyl coenzyme A racemase (AMACR) is a metabolic enzyme whose overexpression has been shown to be a diagnostic indicator of prostatic adenocarcinoma and other solid tumors. Here, we confirm that attenuation of AMACR expression diminishes the growth of prostate cancer cell lines by using stably expressed short-hairpin RNA constructs. This observation strongly suggests that the AMACR enzyme may be a target for therapeutic inhibition in prostate cancer. To this end, we report here a novel assay capable of screening libraries of diverse small molecules for inhibitors of AMACR activity. This assay facilitated the screening of approximately 5,000 unique compounds and the discovery of 7 distinct chemical entities capable of inhibiting AMACR at low micromolar concentrations. The most potent inhibitor discovered is the seleno-organic compound ebselen oxide [inhibitory concentration (IC(50)): 0.80 μmol/L]. The parent compound, ebselen (IC(50): 2.79 μmol/L), is a covalent inactivator of AMACR (K(I)((inact)): 24 μmol/L). Two of the AMACR inhibitors are selectively toxic to prostate cancer cell lines (LAPC4/LNCaP/PC3) that express AMACR compared to a normal prostate fibroblast cell line (WPMY1) that does not express the protein. This report shows the first high-throughput screen for the discovery of novel AMACR inhibitors, characterizes the first nonsubstrate-based inhibitors, and validates that AMACR is a viable chemotherapeutic target in vitro.
Collapse
Affiliation(s)
- Brice A.P. Wilson
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
- James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Haofan Wang
- Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Benjamin A. Nacev
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Ronnie C. Mease
- Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Jun O. Liu
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - Martin G. Pomper
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
- Department of Radiology and Radiological Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
| | - William B. Isaacs
- Department of Pharmacology and Molecular Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD
- James Buchanan Brady Urological Institute, The Johns Hopkins University School of Medicine, Baltimore, MD
| |
Collapse
|
22
|
Wolosker H. Serine racemase and the serine shuttle between neurons and astrocytes. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2011; 1814:1558-66. [PMID: 21224019 DOI: 10.1016/j.bbapap.2011.01.001] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/28/2010] [Revised: 01/02/2011] [Accepted: 01/04/2011] [Indexed: 11/24/2022]
Abstract
d-Serine is a brain-enriched d-amino acid that works as a transmitter-like molecule by physiologically activating NMDA receptors. Synthesis of d-serine is carried out by serine racemase (SR), a pyridoxal 5'-phosphate-dependent enzyme. In addition to carry out racemization, SR α,β-eliminates water from l- or d-serine, generating pyruvate and NH(4)(+). Here I review the main mechanisms regulating SR activity and d-serine dynamics in the brain. I propose a role for SR in a novel form of astrocyte-neuron communication-the "serine shuttle", whereby astrocytes synthesize and export l-serine required for the synthesis of d-serine by the predominantly neuronal SR. d-Serine synthesized and released by neurons can be further taken up by astrocytes for storage and activity-dependent release. I discuss how SR α,β-elimination with d-serine itself may limit the achievable intracellular d-serine concentration, providing a mechanistic rationale on why neurons do not store as much d-serine as astrocytes. The higher content of d-serine in astrocytes appears to be related to increased d-serine stability, for their low SR expression will prevent substantial d-serine metabolism via α,β-elimination. SR and the serine shuttle pathway are therapeutic targets in neurodegenerative diseases in which NMDA receptor dysfunction plays pathological roles. This article is part of a Special Issue entitled: Pyridoxal Phospate Enzymology.
Collapse
Affiliation(s)
- Herman Wolosker
- Department of Biochemistry, B. Rappaport Faculty of Medicine, Technion-Israel Institute of Technology, Haifa 31096, Israel.
| |
Collapse
|
23
|
Machon U, Büchold C, Stempka M, Schirmeister T, Gelhaus C, Leippe M, Gut J, Rosenthal PJ, Kisker C, Leyh M, Schmuck C. On-bead screening of a combinatorial fumaric acid derived peptide library yields antiplasmodial cysteine protease inhibitors with unusual peptide sequences. J Med Chem 2009; 52:5662-72. [PMID: 19715342 DOI: 10.1021/jm900629w] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
A new class of cysteine protease inhibitors based on fumaric acid derived oligopeptides was successfully identified from a high-throughput screening of a solid-phase bound combinatorial library. As target enzymes falcipain and rhodesain were used, which play important roles in the life cycles of the parasites which cause malaria (Plasmodium falciparum) and African sleeping sickness (Trypanosoma brucei rhodesiense). The best inhibitors with unusual amino acid sequences not reported before for this type of enzyme were also fully analyzed in detail in solution. K(i) values in the lower micromolar and even nanomolar region were found. Some inhibitors are even active against plasmodia and show good selectivity relative to other enzymes. Also the mechanism of action was studied and could be shown to be irreversible inhibition.
Collapse
Affiliation(s)
- Uwe Machon
- Institute of Organic Chemistry, University of Duisburg-Essen, Universitatstrasse 7, 45141 Essen, Germany
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Hoffman HE, Jirásková J, Cígler P, Šanda M, Schraml J, Konvalinka J. Hydroxamic Acids As a Novel Family of Serine Racemase Inhibitors: Mechanistic Analysis Reveals Different Modes of Interaction with the Pyridoxal-5′-phosphate Cofactor. J Med Chem 2009; 52:6032-41. [DOI: 10.1021/jm900775q] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hillary E. Hoffman
- Gilead Sciences and IOCB Research Center, Institute of Organic Chemistry and Biochemistry of the ASCR, v. v. i., Flemingovo n. 2, 166 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, Czech Republic
| | - Jana Jirásková
- Gilead Sciences and IOCB Research Center, Institute of Organic Chemistry and Biochemistry of the ASCR, v. v. i., Flemingovo n. 2, 166 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, Czech Republic
| | - Petr Cígler
- Gilead Sciences and IOCB Research Center, Institute of Organic Chemistry and Biochemistry of the ASCR, v. v. i., Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Miloslav Šanda
- Gilead Sciences and IOCB Research Center, Institute of Organic Chemistry and Biochemistry of the ASCR, v. v. i., Flemingovo n. 2, 166 10 Prague 6, Czech Republic
| | - Jan Schraml
- Institute of Chemical Process Fundamentals of the ASCR, v. v. i., Rozvojová 135, 165 02 Prague 6, Czech Republic
| | - Jan Konvalinka
- Gilead Sciences and IOCB Research Center, Institute of Organic Chemistry and Biochemistry of the ASCR, v. v. i., Flemingovo n. 2, 166 10 Prague 6, Czech Republic
- Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 2, Czech Republic
| |
Collapse
|
25
|
Hoffman HE, Jirásková J, Ingr M, Zvelebil M, Konvalinka J. Recombinant human serine racemase: Enzymologic characterization and comparison with its mouse ortholog. Protein Expr Purif 2009; 63:62-7. [DOI: 10.1016/j.pep.2008.09.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 08/29/2008] [Accepted: 09/04/2008] [Indexed: 10/21/2022]
|
26
|
Glickman JF, Schmid A, Ferrand S. Scintillation Proximity Assays in High-Throughput Screening. Assay Drug Dev Technol 2008; 6:433-55. [DOI: 10.1089/adt.2008.135] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
| | - Andres Schmid
- Novartis Institutes for BioMedical Research, Basel, Switzerland
| | | |
Collapse
|
27
|
Abstract
Rapid progress in the synthetic application of benzotriazole derivatives in the last 20 years has resulted in over 1000 scientific papers on the subject. This fact is reflected in Section 5.01.7, which involves almost a half of the volume of this chapter. The section is arranged according to hybridization of the C-α atom and atomic numbers of the atoms in positions β and γ to allow an easy access to the material of interest. Recent discovery of copper catalysis in [3+2] cycloadditions of azides to acetylenes, the so-called ‘click chemistry’, which boosted application of the 1,2,3-triazole derivatives, especially in medicinal chemistry, is presented in Section 5.01.9. From the point of view of practical applications, Section 5.01.11 is organized according to the number, position, and combination of the substituents at the aromatic rings. Another novel feature that has no precedence in the previous editions of Comprehensive Heterocyclic Chemistry is an addition of triazole and benzotriazole complexes with various transitions metals to Section 5.01.4.
Collapse
|
28
|
Dolle RE, Le Bourdonnec B, Goodman AJ, Morales GA, Salvino JM, Zhang W. Comprehensive survey of chemical libraries for drug discovery and chemical biology: 2006. ACTA ACUST UNITED AC 2007; 9:855-902. [PMID: 17877417 DOI: 10.1021/cc700111e] [Citation(s) in RCA: 75] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roland E Dolle
- Adolor Corporation, 700 Pennsylvania Drive, Exton, Pennsylvania 19341, USA.
| | | | | | | | | | | |
Collapse
|
29
|
Wolosker H. NMDA Receptor Regulation by D-serine: New Findings and Perspectives. Mol Neurobiol 2007; 36:152-64. [DOI: 10.1007/s12035-007-0038-6] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2006] [Accepted: 02/28/2007] [Indexed: 10/22/2022]
|