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 b-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 noncooperative glycine binding15-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 lM 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.

ATP binding to human serine racemase is cooperative and modulated by glycine / Marchetti, Marialaura; Bruno, Stefano; Campanini, Barbara; Peracchi, Alessio; Mai, N; Mozzarelli, Andrea. - In: THE FEBS JOURNAL. - ISSN 1742-464X. - 280:(2013), pp. 5853-5863. [10.1111/febs.12510]

ATP binding to human serine racemase is cooperative and modulated by glycine

MARCHETTI, Marialaura;BRUNO, Stefano;CAMPANINI, Barbara;PERACCHI, Alessio;MOZZARELLI, Andrea
2013-01-01

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 b-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 noncooperative glycine binding15-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 lM 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.
2013
ATP binding to human serine racemase is cooperative and modulated by glycine / Marchetti, Marialaura; Bruno, Stefano; Campanini, Barbara; Peracchi, Alessio; Mai, N; Mozzarelli, Andrea. - In: THE FEBS JOURNAL. - ISSN 1742-464X. - 280:(2013), pp. 5853-5863. [10.1111/febs.12510]
File in questo prodotto:
File Dimensione Formato  
abstract.docx

non disponibili

Tipologia: Abstract
Licenza: Creative commons
Dimensione 12.09 kB
Formato Microsoft Word XML
12.09 kB Microsoft Word XML   Visualizza/Apri   Richiedi una copia
febs12510-published.pdf

non disponibili

Tipologia: Documento in Post-print
Licenza: Creative commons
Dimensione 319.73 kB
Formato Adobe PDF
319.73 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11381/2651733
Citazioni
  • ???jsp.display-item.citation.pmc??? ND
  • Scopus 32
  • ???jsp.display-item.citation.isi??? 30
social impact