Related Experiment Video
Updated: May 30, 2025

Rapid Analysis of Circadian Phenotypes in Arabidopsis Protoplasts Transfected with a Luminescent Clock Reporter
Published on: September 17, 2016
Enthalpy driven temperature-sensitive conformational changes in a metamorphic protein involved in the cyanobacterial
Buyuan Ma1, Zengxin Ma2, Ning Zhang3
1College of Life Sciences, Qingdao Agricultural University, Qingdao 266109, China; Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, China.
Abstract:
Metamorphic proteins switch reversibly between distinctly different folds often with different functions under physiological conditions. Here, the kinetics and thermodynamics of the fold-switching at different temperatures in a metamorphic protein, KaiB, involved in cyanobacterial circadian clock, reveal that enthalpy-driven the fold-switching to form fold-switched KaiB (fsKaiB) and the fsKaiB and ground-state KaiB (gsKaiB) are more dominantly at lower and higher temperatures, respectively. Thermodynamic analysis indicates that conformational and solvent entropy have opposing effects on KaiB's fold-switching. The folding kinetic reveals that as KaiB folds, it preferentially folds into gsKaiB and then switches fold to fsKaiB. Temperature-sensitive protein fold-switching can be further extended into applications, such as new temperature-sensitive molecular switcher and biosensors development.
Related Concept Videos
Circadian Rhythms and Gene Regulation
Biological Clocks and Seasonal Responses
Protein Denaturation
¹H NMR of Conformationally Flexible Molecules: Variable-Temperature NMR
Energy to Drive Translocation
Generally, polypeptides are unfolded by two distinct...
Responses to Heat and Cold Stress

