Makhatadze G I, Marahiel M A
Department of Biology, Johns Hopkins University, Baltimore, Maryland 21218.
Protein Sci. 1994 Nov;3(11):2144-7. doi: 10.1002/pro.5560031127.
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.
利用扫描量热法和尺寸排阻色谱法，研究了枯草芽孢杆菌主要冷休克蛋白（CspB）在不同盐（包括磷酸盐）存在下于溶液中的分子间相互作用。量热结果表明，在所有情况下，蛋白质的去折叠都可以用二态模型近似，但去折叠模式可能因条件而异。在磷酸盐存在下，协同折叠单元是单体，而在没有磷酸盐时，协同单元是二聚体。尺寸排阻色谱法证实了有无磷酸盐时CspB自缔合的差异。将这些结果与最近关于CspB在晶体和溶液中的结构研究进行了比较。
