Home  |  About JAPTR |  Editorial board  |  Search |  Ahead of print  |  Current issue  |  Archives |  Submit article  |  Instructions  |  Subscribe  |  Advertise  |  Contacts  |Login 
Users Online: 609   Home Print this page Email this page Small font sizeDefault font sizeIncrease font size
     

 Table of Contents  
ORIGINAL ARTICLE
Year : 2022  |  Volume : 13  |  Issue : 3  |  Page : 232-237  

Serine racemase interaction with N-methyl-D-aspartate receptors antagonist reveals potential alternative target of chronic pain treatment: Molecular docking study


1 Department of Anesthesiology and Intensive Therapy, Faculty of Medicine, Brawijaya University/Dr. Saiful Anwar General Hospital, Malang, Indonesia
2 Department of Internal Medicine, Faculty of Medicine, Brawijaya University/Dr Saiful Anwar General Hospital, Malang, Indonesia
3 Department of Cardiology and Vascular Medicine, Faculty of Medicine, Brawijaya University/Dr Saiful Anwar General Hospital, Malang, Indonesia
4 Department of Biology, Faculty of Mathematics and Natural Science, Brawijaya University, Malang, Indonesia
5 Department of Anesthesiology, Intensive Care and Pain Management, Faculty of Medicine, Hasanuddin University, Makassar, Indonesia

Date of Submission17-Mar-2022
Date of Decision04-May-2022
Date of Acceptance24-Jun-2022
Date of Web Publication05-Jul-2022

Correspondence Address:
Dr. Ristiawan Muji Laksono
Department of Anesthesiology and Intensive Therapy, Faculty of Medicine, Brawijaya University/Dr. Saiful Anwar Malang, Jl. Jaksa Agung Suprapto no. 2 Malang, East Java
Indonesia
Login to access the Email id

Source of Support: None, Conflict of Interest: None


DOI: 10.4103/japtr.japtr_72_22

Rights and Permissions
  Abstract 


Serine racemase (SR) catalyzes L-serine racemization to activate the N-methyl-D-aspartate receptor (NMDAR). NMDAR activation is associated with the progression of acute-to-chronic neuropathic pain. This study aimed to investigate NMDAR antagonist interactions with SR to obtain potential chronic pain target therapy. Several NMDAR antagonist drugs were obtained from the drug bank, and malonate was used as a control inhibitor. Ligands were prepared using the open babel feature on PyRx. The SR structure was obtained from Protein data bank (PDB) (3l6B) and then docked with ligands using the AutoDock Vina. Haloperidol had a lower binding affinity than malonate and other ligands. Ethanol had the highest binding affinity than other drugs but could bind to the Adenosine triphosphate (ATP)-binding domain. Haloperidol is bound to reface that function for reprotonation in racemization reaction to produce D-serine. Halothane bond with Arg135 residues aligned negatively charged substrates to be reprotonated properly by reface. Tramadol is bound to amino acid residues in the triple serine loop, which determines the direction of the SR reaction. Several NMDAR antagonists such as haloperidol, halothane, ethanol, and tramadol bind to SR in the specific binding site. It reveals that SR potentially becomes an alternative target for chronic pain treatment.

Keywords: Chronic pain, N-methyl-D-aspartate receptor, serine racemase, treatment


How to cite this article:
Laksono RM, Kalim H, Rohman MS, Widodo N, Ahmad MR. Serine racemase interaction with N-methyl-D-aspartate receptors antagonist reveals potential alternative target of chronic pain treatment: Molecular docking study. J Adv Pharm Technol Res 2022;13:232-7

How to cite this URL:
Laksono RM, Kalim H, Rohman MS, Widodo N, Ahmad MR. Serine racemase interaction with N-methyl-D-aspartate receptors antagonist reveals potential alternative target of chronic pain treatment: Molecular docking study. J Adv Pharm Technol Res [serial online] 2022 [cited 2022 Dec 8];13:232-7. Available from: https://www.japtr.org/text.asp?2022/13/3/232/349845




  Introduction Top


Neuropathic pain is more difficult to treat than other types of chronic pain. This condition can reduce the patient's quality of life by affecting daily activity, loss of ability and productivity to work, and increased costs associated with informal assistance by friends and families, which pose a considerable economic burden.[1],[2] Neuropathic pain symptoms are complex, and it is challenging to determine an adequate treatment. Understanding the pathophysiology of neuropathic pain can help develop appropriate diagnostic and intervention procedures.[3]

Neuropathic pain involves central sensitization caused by the opening N-methyl-D-aspartate receptor (NMDAR), either in the peripheral or central nerves.[4] The NMDAR is activated by glutamate, co-agonists glycine, or D-serine. Glycine or D-serine binds to the GluN1 subunit, the obligatory subunit in NMDAR heteromers.[5] D-serine is more potent in activating NMDAR, ten times stronger than glycine.[6] Since activation of NMDA receptor regulated by binding of glutamate, co-agonist glycine, or D-serine, inhibition of its ligands-receptor binding could lower the activation of NMDAR.[7] This inhibition is used in several drugs that act as a noncompetitive antagonist of NMDAR.

D-serine is a product of L-serine racemization by serine racemase (SR).[8] The reduction of D-serine is associated with a decrease in pain symptoms.[9] Inhibition of SR activity may occur through interaction with noncompetitive antagonists of NMDA.[10] SR is found in astrocytes and fibroblasts, and Schwann cells of the sciatic nerve.[11] This inhibition of this enzyme might also help lower pain originating from the peripheral nerve.

NMDAR hyperactivation due to an excess of D-serine plays a role in the emergence of various diseases, including neuropathic pain.[9] NMDA receptor antagonists are widely used to treat chronic pain.[12] A study reported that NMDA antagonist, i. e., (r, s)-ketamine, could reduce pain and lower D-serine blood concentration immediately after infusion in ketamine responder.[13] R-ketamine lowers the intracellular and extracellular D-serine while S-ketamine decreases only extracellular D-serine. A study by Laurido et al.[14] found that intrathecal injection of L-serine-O-sulfate and L-erythro-3-hydroxyaspartate could reduce D-serine by SR inhibition in mice. However, the study assessing SR as potential chronic pain target therapy is limited. Furthermore, this in silico study aims to investigate the interaction between NMDAR antagonist and SR, which can provide information about SR as potential chronic pain target therapy.


  Material and Methods Top


Ligand and protein data mining

Ligands were searched using a drug bank (www.drugbank.com) with the keyword NMDA receptor antagonist. Ligands 3D structure were downloaded from PubChem including L-serine (CID: 5951), malonate (CID: 9084), agmatine (CID: 199), amantadine (CID: 2130), chloroprocaine (CID: 8612), dextromethorphan (CID: 5360696), felbamate (CID: 3331), ethanol (702), haloperidol (CID: 3559), halothane (CID: 3562), ifenprodil (CID: 3689), ketamine (CID: 3821), methadone (CID: 4095), memantine (CID: 4054), meperidine (4058), methoxetamine (CID: 52911279), orphenadrine (CID: 4601), phencyclidine (CID: 6468), procaine (CID: 4914), and tramadol (CID 33741) [Table 1]. SR was used as a receptor and mined from PDB http//www.rscb.org/pdb with ID 3l6B [Figure 1].
Table 1: Two-dimensional structure of N-methyl-D-aspartate receptor antagonist

Click here to view
Figure 1: Serine racemase (PDB ID 3l6B)

Click here to view


Molecular docking of ligand and receptor

Ligands were prepared using PyRx 0.8 to minimize the binding energy of the ligand, and SR was prepared using Discovery Studio v. 19 software to remove any ligand or water bound to the receptors. The receptors appear in dimers, and both had equivalent structures; thus, the monomeric were used for the calculations. Ligands and enzymes were docked and analyzed using AutoDock Vina. Docking is done by targeting several amino acid residues in SR based on known active sites and important binding domains,[15] including R-135, S-242, S-84, S-83, H-87, D-132, E-136, P-231, K-241, H-82, P-153, D-238, G-239, N-86, N-154, G-85, N-229, S-243, and H-152. Energy calculations are performed with each of these servers. The docking results were visualized using PyMol and Discovery Studio.


  Results Top


Ligand data mining was shown in [Table 1], consisting of compound name, 2D structure, and its function in pain treatment. Protein data mining is shown in [Figure 1].

Based on the docking result, malonate, a potent SR inhibitor, forms 10 hydrogen bonds with SR at the amino acid residue Ser83, Ser84 (3 bonds), Gly65, Asn86, His87, Arg135, Ser242, and Gly239 with a binding energy of –6 kcal/mol [Table 2]. Docking between NMDAR antagonist and SR shows that haloperidol bind to Ser84 residue with the lowest binding energy than other antagonists (–7.3 kcal/mol). Haloperidol forms five bond types: carbon-hydrogen bond, halogen; pi-anion; amide-pi; and pi-alkyl. Ethanol bonds with amino acid residues Ser84, Asn86, and His87 with a binding affinity of –3.3 kcal/mol. Ethanol forms a hydrogen bond and is an unfavorable donor. Felbamate and ifenprodil did not share the same residues with control but had an equal binding affinity with malonate (–6 kcal/mol). Halothane binds to the amino acid residue Arg135 (–4 kcal/mol). Halothane forms three bonds: carbon-hydrogen bond, halogen, and alkyl. Other NMDAR antagonists include ketamine, amantadine, chloroprocaine, dextromethorphan, meperidine, methoxetamine, orphenadrine, phencyclidine, methadone, tramadol, and procaine did not share the same amino acid residue with control. However, tramadol bind to the SR-specific binding site Asn154 [Table 3]. Based on the docking simulation, four NMDAR antagonists are known to form an interaction with SR. The two-dimension docking model is shown in [Figure 2].
Table 2: The binding affinity and amino acid residues of serine racemase and ligands

Click here to view
Table 3: Specific binding site of several compounds in serine racemase

Click here to view
Figure 2: 2D Visualization of molecular docking between (a). Haloperidol and serin racemase, (b). Halothane and serine racemase, (c) ethanol and serine racemase, and (d) Tramadol and serine racemase. The interaction formed showed in colors

Click here to view



  Discussion Top


Neuropathic pain involves a variety of pathological mechanisms in the central and peripheral nervous systems. Peripheral NMDAR interaction with D-serine plays a role in central sensitization, increasing synaptic neurons' excitability and efficacy in spinal pain pathways.[16] D-serine is made in presynaptic neurons and acts as an NMDAR co-agonist by binding to the glycine binding site. Basal D-serine levels are important in synaptic efficiency and long-term potentiation[17] and play a role in central sensitization in the occurrence of pain.[16] D-serine is produced from 3-phosphoglycerate to become L-serine in astroglia, then shuttled to presynaptic neurons containing SR.[18]

SR is allosterically activated by ATP and requires Mg2+ and Mn2+ cations. The amino acid residue Ser84 is a reface of SR. Another active site is on the si face, which is located on Ser56. L-serine that binds to the si face will undergo alpha deprotonation on external aldimine, producing carbanionic or quinonoid intermediate. Further protonation of quinonoid intermediates by reface will produce D-serine (racemization), while expulsion of the β-OH group, possibly followed by protonation, will produce enamine that is eventually released as pyruvate.[19] The β-elimination reaction is four times more favorable than the racemization reaction[20] maintaining the D-serine level in the tissue.

The study showed that haloperidol bind with the Ser84 residue, a reface of the SR, with the strongest binding energy than other compounds. The binding to Ser84 is thought to inhibit the reprotonation process required for the racemization reaction. The study of mutations in the Ser84 residue abolished the racemization process and increased β-elimination products while using L-threo-hydroxyaspartate and L-serine-O-sulfate as substrates.[20],[21] Ethanol also binds to the Ser84 residue, but ethanol has the weakest binding energy among other ligands.

Halothane binds to the Arg135 residue through fluorine which was negatively charged. The negatively charged substrate will bind to the Arg135 residue through a salt bridge to be aligned for deprotonation as in malonate.[20] These amino acid residues are essential for negatively charged substrates to align for deprotonation properly. Mutation of Ser84 to aspartate causes the formation of a salt bridge of Asp84 with Arg135, which prevents negatively charged substrates from being protonated to produce D-serine.[20]

Tramadol can bind to the amino acid residue Asp154, a triple serine loop consisting of residues His152, Pro153, Asn154, and Gln155. The triple serine loop plays a role in determining the direction of the reaction toward racemization or β-elimination. Mutation of amino acid residues in this region can lead to a tendency toward racemization, lowering the β-elimination yield.[22] Ethanol can bind to the Asn86 residue, which is the binding domain of ATP. ATP is essential in increasing the ability of the enzyme as a catalyst.[22] Mutations in the ATP binding domain decrease the catalytic ability of SR.[23] A study on Gln155 mutation to aspartate caused cells to favor racemization of L-ser to D-ser compared to β-elimination reaction.[24] Cell death after nerve injury involving activation of NMDAR and decreased GABA receptors causes the transition to chronic neuropathic pain and becomes difficult to treat.[25] These findings show that SR also potentially become a chronic pain treatment target besides NMDAR inhibition. Based on this study, further studies such as SR antagonists drug synthesis can be established in managing chronic neuropathic pain.


  Conclusion Top


SR potentially becomes an alternative target for neuropathic pain treatment. Some NMDAR antagonist drugs interfere with the SR racemization catalysis, such as haloperidol by binding to the reface, halothane by binding to amino acid residues that direct protonation, ethanol by binding to the ATP binding domain, and tramadol by binding to the “triple serine loop” residue which determines the direction of the reaction.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.



 
  References Top

1.
Liedgens H, Obradovic M, De Courcy J, Holbrook T, Jakubanis R. A burden of illness study for neuropathic pain in Europe. Clinicoecon Outcomes Res 2016;8:113-26.  Back to cited text no. 1
    
2.
McDermott AM, Toelle TR, Rowbotham DJ, Schaefer CP, Dukes EM. The burden of neuropathic pain: Results from a cross-sectional survey. Eur J Pain 2006;10:127-35.  Back to cited text no. 2
    
3.
Colloca L, Ludman T, Bouhassira D, Baron R, Dickenson AH, Yarnitsky D, et al. Neuropathic pain. Nat Rev Dis Primers 2017;3:17002.  Back to cited text no. 3
    
4.
Petrenko AB, Yamakura T, Baba H, Shimoji K. The role of N-methyl-D-aspartate (NMDA) receptors in pain: A review. Anesth Analg 2003;97:1108-16.  Back to cited text no. 4
    
5.
Hansen KB, Yi F, Perszyk RE, Menniti FS, Traynelis SF. NMDA receptors in the central nervous system. Methods Mol Biol 2017;1677:1-80.  Back to cited text no. 5
    
6.
Berger AJ, Dieudonné S, Ascher P. Glycine uptake governs glycine site occupancy at NMDA receptors of excitatory synapses. J Neurophysiol 1998;80:3336-40.  Back to cited text no. 6
    
7.
Acton D, Miles GB. Differential regulation of NMDA receptors by d-serine and glycine in mammalian spinal locomotor networks. J Neurophysiol 2017;117:1877-93.  Back to cited text no. 7
    
8.
Tilley DM, Cedeño DL, Vetri F, Platt DC, Vallejo R. Differential target multiplexed spinal cord stimulation programming modulates proteins involved in ion regulation in an animal model of neuropathic pain. Mol Pain 2022;18:1-14.  Back to cited text no. 8
    
9.
Lefèvre Y, Amadio A, Vincent P, Descheemaeker A, Oliet SH, Dallel R, et al. Neuropathic pain depends upon D-serine co-activation of spinal NMDA receptors in rats. Neurosci Lett 2015;603:42-7.  Back to cited text no. 9
    
10.
Singh NS, Bernier M, Camandola S, Khadeer MA, Moaddel R, Mattson MP, et al. Enantioselective inhibition of D -serine transport by (S)-ketamine: S -Ketamine attenuates ASCT2 transport. Br J Pharmacol 2015;172:4546-59.  Back to cited text no. 10
    
11.
Wu S, Barger SW, Sims TJ. Schwann cell and epineural fibroblast expression of serine racemase. Brain Res 2004;1020:161-6.  Back to cited text no. 11
    
12.
Hewitt DJ. The use of NMDA-receptor antagonists in the treatment of chronic pain. Clin J Pain 2000;16:S73-9.  Back to cited text no. 12
    
13.
Moaddel R, Luckenbaugh DA, Xie Y, Villaseñor A, Brutsche NE, Machado VR. et al. D-serine plasma concentration is a potential biomarker of (R, S)-ketamine antidepressant response in subjects with treatment-resistant depression. Psychopharmacology 2015;232:399-409.  Back to cited text no. 13
    
14.
Laurido C, Hernández A, Pelissier T, Constandil L. Antinociceptive effect of rat D-serine racemase inhibitors, L-serine-O-sulfate, and L-erythro-3-hydroxyaspartate in an arthritic pain model. ScientificWorldJournal 2012;2012:279147.  Back to cited text no. 14
    
15.
Rani K, Tyagi M, Mazumder M, Singh A, Shanmugam A, Dalal K, et al. Accelerated identification of serine racemase inhibitor from Centella asiatica. Sci Rep 2020;10:4640.  Back to cited text no. 15
    
16.
Choi SR, Moon JY, Roh DH, Yoon SY, Kwon SG, Choi HS, et al. Spinal D-serine increases PKC-dependent GluN1 phosphorylation contributing to the sigma-1 receptor-induced development of mechanical allodynia in a mouse model of neuropathic pain. J Pain 2017;18:415-27.  Back to cited text no. 16
    
17.
Panatier A, Theodosis DT, Mothet JP, Touquet B, Pollegioni L, Poulain DA, et al. Glia-derived D-serine controls NMDA receptor activity and synaptic memory. Cell 2006;125:775-84.  Back to cited text no. 17
    
18.
Wolosker H, Balu DT, Coyle JT. The rise and fall of the D-serine-mediated gliotransmission hypothesis. Trends Neurosci 2016;39:712-21.  Back to cited text no. 18
    
19.
Graham DL, Beio ML, Nelson DL, Berkowitz DB. Human serine racemase: Key residues/active site motifs and their relation to enzyme function. Front Mol Biosci 2019;6:8.  Back to cited text no. 19
    
20.
Nelson DL, Applegate GA, Beio ML, Graham DL, Berkowitz DB. Human serine racemase structure/activity relationship studies provide mechanistic insight and point to position 84 as a hot spot for β-elimination function. J Biol Chem 2017;292:13986-4002.  Back to cited text no. 20
    
21.
Strísovský K, Jirásková J, Mikulová A, Rulísek L, Konvalinka J. Dual substrate and reaction specificity in mouse serine racemase: Identification of high-affinity dicarboxylate substrate and inhibitors and analysis of the beta-eliminase activity. Biochemistry 2005;44:13091-100.  Back to cited text no. 21
    
22.
Uda K, Abe K, Dehara Y, Mizobata K, Edashige Y, Nishimura R, et al. Triple serine loop region regulates the aspartate racemase activity of the serine/aspartate racemase family. Amino Acids 2017;49:1743-54.  Back to cited text no. 22
    
23.
Canosa AV, Faggiano S, Marchetti M, Armao S, Bettati S, Bruno S, et al. Glutamine 89 is a key residue in the allosteric modulation of human serine racemase activity by ATP. Sci Rep 2018;8:9016.  Back to cited text no. 23
    
24.
Talukdar G, Inoue R, Yoshida T, Ishimoto T, Yaku K, Nakagawa T, et al. Novel role of serine racemase in anti-apoptosis and metabolism. Biochim Biophys Acta Gen Subj 2017;1861:3378-87.  Back to cited text no. 24
    
25.
Inquimbert P, Moll M, Latremoliere A, Tong CK, Whang J, Sheehan GF, et al. NMDA receptor activation underlies the loss of spinal dorsal horn neurons and the transition to persistent pain after peripheral nerve injury. Cell Rep 2018;23:2678-89.  Back to cited text no. 25
    


    Figures

  [Figure 1], [Figure 2]
 
 
    Tables

  [Table 1], [Table 2], [Table 3]



 

Top
 
 
  Search
 
    Similar in PUBMED
   Search Pubmed for
   Search in Google Scholar for
 Related articles
    Access Statistics
    Email Alert *
    Add to My List *
* Registration required (free)  

 
  In this article
   Abstract
  Introduction
  Material and Methods
  Results
  Discussion
  Conclusion
   References
   Article Figures
   Article Tables

 Article Access Statistics
    Viewed526    
    Printed32    
    Emailed0    
    PDF Downloaded63    
    Comments [Add]    

Recommend this journal