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Tyrosine nitration moderates the peptidase activity of human methionyl aminopeptidase 2

John Y Ng1, Joyce Chiu, Philip J Hogg

  • 1Lowy Cancer Research Centre and the Prince of Wales Clinical School, University of New South Wales, Sydney, NSW 2052, Australia.

Biochemical and Biophysical Research Communications
|September 18, 2013
PubMed

Insights

Nitration of methionyl aminopeptidase 2 (MetAP2) significantly reduces its enzymatic activity. This finding suggests that MetAP2 nitration may contribute to endothelial dysfunction.

Area of Science:

  • Biochemistry
  • Molecular Biology
  • Physiology

Background:

  • Methionyl aminopeptidase 2 (MetAP2) is crucial for regulating angiogenesis, the formation of new blood vessels.
  • Endothelial dysfunction is a key factor in various cardiovascular diseases.

Purpose of the Study:

  • To investigate the impact of nitration on MetAP2 enzymatic activity.
  • To identify the specific site of nitration on MetAP2.

Main Methods:

  • In vitro assessment of enzymatic activity of unmodified, nitrated, and oxidized MetAP2 using a chromogenic substrate.
  • Mass spectrometry to identify nitrated residues.
  • Structural and evolutionary analysis of identified residues.

Main Results:

  • Nitration significantly decreased MetAP2's ability to cleave the chromogenic substrate.
  • Mass spectrometry identified tyrosine 336 (Tyr336) as the nitrated residue.
  • Structural and evolutionary analyses confirmed Tyr336's importance for MetAP2 activity.

Conclusions:

  • The enzymatic activity of MetAP2 is impaired by nitration.
  • Nitration of MetAP2 at Tyr336 is a potential mechanism contributing to endothelial dysfunction.
Keywords:
Endothelial dysfunctionMethionyl aminopeptidase 2NitrationNitrotyrosine

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