Structural stability and reversible unfolding of recombinant porcine S100A12

Biophys Chem. 2008 May;134(3):246-53. doi: 10.1016/j.bpc.2008.02.013. Epub 2008 Feb 29.

Abstract

Porcine S100A12 is a member of the S100 proteins, family of small acidic calcium-binding proteins characterized by the presence of two EF-hand motifs. These proteins are involved in many cellular events such as the regulation of protein phosphorylation, enzymatic activity, protein-protein interaction, Ca2+ homeostasis, inflammatory processes and intermediate filament polymerization. In addition, members of this family bind Zn2+ or Ca2+ with cooperative effect on binding. In this study, the gene sequence encoding porcine S100A12 was obtained by the synthetic gene approach using E. coli codon bias. Additionally, we report a thermodynamic study of the recombinant S100A12 using circular dichroism, fluorescence and isothermal titration calorimetry. The results of urea and temperature induced unfolding and refolding processes indicated a reversible two-state process. Also, the ANS fluorescence studies showed that in presence of divalent ions the protein exposes hydrophobic sites which could facilitate the interaction with other proteins and trigger the physiological responses.

MeSH terms

  • Animals
  • Calcium / chemistry
  • Calcium / metabolism
  • Calorimetry
  • Circular Dichroism
  • Gene Expression
  • Hydrogen-Ion Concentration
  • Protein Binding
  • Protein Denaturation
  • Protein Folding*
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / classification
  • Recombinant Proteins / isolation & purification
  • Recombinant Proteins / metabolism
  • S100 Proteins / chemistry*
  • S100 Proteins / classification
  • S100 Proteins / isolation & purification
  • S100 Proteins / metabolism*
  • Swine / metabolism*
  • Temperature
  • Thermodynamics
  • Zinc / chemistry
  • Zinc / metabolism

Substances

  • Recombinant Proteins
  • S100 Proteins
  • Zinc
  • Calcium