Recombinant human serine racemase: enzymologic characterization and comparison with its mouse ortholog

Protein Expr Purif. 2009 Jan;63(1):62-7. doi: 10.1016/j.pep.2008.09.003. Epub 2008 Sep 11.

Abstract

D-serine plays a key role in glutamatergic neurotransmission in mammalian brain as a co-agonist of N-methyl-D-aspartate receptors. The enzyme responsible for D-serine biosynthesis, serine racemase (SR), is therefore a promising target for treatment of neuropathologies related to glutamate receptor excitotoxicity, such as stroke or Alzheimer's disease. Much of the experimental work to date has been performed on mouse serine racemase, which shares a high level of sequence identity with its human ortholog. In this work, we report the synthesis of a human SR gene variant optimized for heterologous expression in Escherichia coli and describe the expression and purification of active recombinant human SR. This strategy may be of general interest to researchers wishing to express mammalian proteins in a bacterial system. Furthermore, we conduct a thorough analysis of the kinetics and inhibitor-sensitivity of the recombinant enzyme, and we provide the first direct comparison of human and mouse SR based on our kinetic data. The orthologs behave similarly overall and exhibit identical inhibition profiles, validating the use of mouse models in SR research.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Ammonium Sulfate
  • Animals
  • Chromatography, Affinity
  • Circular Dichroism
  • Cloning, Molecular
  • Humans
  • Mice
  • Molecular Sequence Data
  • Racemases and Epimerases / chemistry
  • Racemases and Epimerases / genetics
  • Racemases and Epimerases / isolation & purification
  • Racemases and Epimerases / metabolism*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / genetics
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • Sequence Alignment

Substances

  • Recombinant Proteins
  • Racemases and Epimerases
  • serine racemase
  • Ammonium Sulfate