Effect of pH and phosphate ions on self-association properties of the major cold-shock protein from Bacillus subtilis.
The intermolecular interactions of the major cold-shock protein from Bacillus subtilis (CspB) in solution in the presence of different salts, including phosphate, have been studied by means of scanning calorimetry and size-exclusion chromatography. Calorimetric results indicate that, in all cases, protein unfolding can be approximated by a 2-state model, but the modes of unfolding can differ depending on the conditions. In the presence of phosphate, the cooperative folding unit is a monomer, whereas in the absence of phosphate, the cooperative unit is a dimer. The difference in the self-association of CspB in the presence and absence of phosphate was supported by size-exclusion chromatography. These results are compared with recent structural studies of CspB in crystal and in solution.
Makhatadze
G I
GI
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
Marahiel
M A
MA
D001412:Bacillus subtilis / Q000737:chemistry; D001426:Bacterial Proteins / Q000737:chemistry* / Q000378:metabolism; D002151:Calorimetry; D002850:Chromatography, Gel; D006863:Hydrogen-Ion Concentration; D008970:Molecular Weight; D010710:Phosphates / Q000378:metabolism / Q000494:pharmacology*; D011487:Protein Conformation; D017510:Protein Folding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D012997:Solvents; D013696:Temperature; D013816:Thermodynamics
D001426:Bacterial Proteins; D010710:Phosphates; D012997:Solvents; C077188:cold-shock protein CspB, Bacteria