Hydrodynamic properties of bovine brain S‐100 proteins

FEBS Letters

Kay, Cyril M.¹  Mani, Rajam S.¹ 

[1] Medical Research Group in Protein Structure and Function, Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada

关键词: S-100 protein;    Ca2+ effect;    K+ effect;    Na+ effect;    Li+ effect CD;    Hydrodynamics;    CD;    circular dichroism;    UV;    ultraviolet;   

DOI  :  10.1016/0014-5793(84)80091-5

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The size of S-100a and S-100b proteins in solution have been examined by gel filtration and ultracentrifugation in the presence and absence of Ca²⁺. S-100a and S-100b proteins, in the absence of Ca²⁺, have intrinsinc sedimentation coefficient, s ^o _20,w of 2.20 and 2.15 S, respectively and in 1 mM Ca²⁺ their s ^o _20,w values decreased to 2.05 and 1.95 S, respectively, indicating an unfolding of the protein molecules. The Stokes radii of S-100a and S-100b (—Ca²⁺) were 23.4 Å and 24.0 Å and they decreased to 22.2 Å and 22.3 Å in the presence of Ca²⁺. The Ca²⁺ effect on S-100b > S-100a was in agreement with our earlier CD observations. Among the monovalent cations tested (K⁺, Na⁺ and Li⁺) K⁺ had the maximum effect on the Stokes radii and s ^o _20,w values of S-100 proteins. Since certain functions of the nervous system are accompanied by local changes in ionic concentrations of Ca²⁺, Na⁺ and K⁺, it is conceivable that these respective conformational changes induced in S-100 proteins by these metals may be related to their function in the brain.

【 授权许可】

Unknown