Effects of Ca2+ on catalytic activity and conformation of trypsin and α-chymotrypsin in aqueous ethanol

M. Kotormán, I. Laczkó, A. Szabó, L. M. Simon

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The effects of calcium ions on the conformation and catalytic activity of trypsin and α-chymotrypsin were studied in aqueous ethanol. The activity of α-chymotrypsin was practically lost within 10min in the presence of 60% ethanol while trypsin preserved about 40% of its original activity even in 85% ethanol at pH 3. The catalytic activity of α-chymotrypsin did not decrease in the presence of 1.2M CaCl2 and 0.6M CaCl2 with trypsin in ethanolic solvent. In the latter case an activation of enzyme was observed. The stabilizing effects of calcium ions were accompanied by an increase in the helical content in both enzymes, as followed by circular dichroism measurements.

Original languageEnglish
Pages (from-to)18-21
Number of pages4
JournalBiochemical and biophysical research communications
Issue number1
Publication statusPublished - Apr 25 2003



  • Calcium ion
  • Ethanol
  • Stability
  • Structure
  • Trypsin
  • α-Chymotrypsin

ASJC Scopus subject areas

  • Biophysics
  • Biochemistry
  • Molecular Biology
  • Cell Biology

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