Related Experiment Video
Updated: Apr 30, 2026

X-Ray Crystallography to Study the Oligomeric State Transition of the Thermotoga maritima M42 Aminopeptidase TmPep1050
Published on: May 13, 2020
Thermal-triggerd proteinquake leads to disassembly of DegP hexamer as an imperative activation step
Shanshan Li1, Rui Wang2, Deyong Li1
1Laboratory of Soft Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing, China 100190.
Abstract:
The Escherichia coli DegP has been reported to function both as molecular chaperone and protease for the quality control of outer membrane protein biogenesis. Activation of the inactive DegP hexamers was believed to occur via their disassembly into trimeric units and subsequent reassembly into larger oligomers (12-mers and 24-mers). Here, we analyzed the thermal stability and the unfolding dynamics of the different secondary structure components of the DegP hexamers using Fourier transform infrared spectroscopy and temperature-jump nanosecond time-resolved IR difference absorbance spectroscopy. We found that the interfacial secondary structure components possess a degreed thermal stability, with the disassembly of the DegP hexamers follows a "proteinquake" manner, such that the fully exposed parts of the interfacial β-sheets serving as the temperature sensor and epicenter to drive the sequential unfolding/disassembly process that finishes within about 134 ns at room temperature.
Related Concept Videos
GTPases and their Regulation
Large G-proteins,...
The Unfolded Protein Response
IP3/DAG Signaling Pathway
Activation and Inactivation of G Proteins
Mechanical Protein Functions
Energy to Drive Translocation
Generally, polypeptides are unfolded by two distinct...

