Determination of binding affinity of metal cofactor to the active site of methionine aminopeptidase based on quantitation of functional enzyme

Sergio C. Chai, Jing Ping Lu, Qi Zhuang Ye

Research output: Contribution to journalArticle

16 Scopus citations


Determination of metal affinity to the active site of metalloenzymes constitutes an integral part in the understanding of enzyme catalysis and regulation. Nonlinear curve fitting of metal titration curves using the multiple independent binding sites (MIBS) model was adapted to determine KD values based on functional enzyme concentrations. This approach provides a more accurate evaluation of KD compared with existing methods that are based on total protein concentrations. We applied this concept to methionine aminopeptidase from Mycobacterium tuberculosis and showed that it is a monometalated enzyme with a KD of 0.13 μM for Co2+.

Original languageEnglish (US)
Pages (from-to)263-264
Number of pages2
JournalAnalytical biochemistry
Issue number2
StatePublished - Dec 15 2009


ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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