Acceleration of oxidative folding of bovine pancreatic ribonuclease A by anion‐induced stabilization and formation of structured native‐like intermediates

FEBS Letters

Shin, Hang-Cheol¹  Low, Lawrence K¹  Narayan, Mahesh¹  Wedemeyer, William J¹  Scheraga, Harold A¹ 

[1] Baker Laboratory of Chemistry and Chemical Biology, Cornell University, Ithaca, NY 14853-1301, USA

关键词: Protein folding;    Ribonuclease A;    Dithiothreitol;    Neutral salt;    Stabilized intermediate;    RNase A;    bovine pancreatic ribonuclease A;    DTTox;    oxidized dithiothreitol;    DTTred;    reduced dithiothreitol;    AEMTS;    2-aminoethyl methanethiosulfonate;    EDTA;    ethylenediaminetetraacetic acid;    Tris–HCl;    tris (hydroxymethyl) aminomethane hydrochloride;    des-[ ];    three-disulfide intermediate lacking a disulfide bond specified within the brackets;   

DOI  :  10.1016/S0014-5793(00)01432-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Phosphate anions accelerate the oxidative folding of reduced bovine pancreatic ribonuclease A with dithiothreitol at several temperatures and ionic strengths. The addition of 400 mM phosphate at pH 8.1 increased the regeneration rate of native protein 2.5-fold at 15°C, 3.5-fold at 25°C, and 20-fold at 37°C, compared to the rate in the absence of phosphate. In addition, the effects of other ions on the oxidative folding of RNase A were examined. Fluoride was found to accelerate the formation of native protein under the same oxidizing conditions. In contrast, cations of high charge density or ions with low charge density appear to have an opposite effect on the folding of RNase A. The catalysis of oxidative folding results largely from an anion-dependent stabilization and formation of tertiary structure in productive disulfide intermediates (des-species). Phosphate and fluoride also accelerate the initial equilibration of unstructured disulfide ensembles, presumably due to non-specific electrostatic and hydrogen bonding effects on the protein and solvent.

【 授权许可】

Unknown