Interaction of hsp70 with unfolded proteins: effects of temperature and nucleotides on the kinetics of binding.

作者：Daniel R. Palleros, William J. Welch, Anthony L. Fink · 发表于：Proceedings of the National Academy of Sciences · 年份：1991 · DOI：10.1073/pnas.88.13.5719 · 被引用次数：335 · 研究领域：Heat shock proteins research、thermodynamics and calorimetric analyses、Protein Structure and Dynamics

Circular dichroism and HPLC gel filtration were used to show that cytosolic hsp70 is thermally stable but undergoes a conformational transition (midpoint, 43 degrees C; 57 degrees C in the presence of ATP or ADP) leading to oligomerization. hsp70 binds to unfolded, but not to folded, proteins in a temperature-dependent manner; complex formation is significant only at physiologically relevant temperatures. hsp70 binds ADP more tightly than ATP to form a binary complex, which binds to the unfolded protein more rapidly than free hsp70. ADP also inhibits the ATP-induced dissociation of the hsp70-protein complex. A regulatory role for the hsp70-nucleotide binary complexes is proposed.