Temperature jump protein assembly

Biochemical processes such as protein unfolding/refold-ing and supramolecular assembly/disassembly take place on a time scale of seconds to minutes after readjusting the temperature of a system. Most commercially available glass-jacketed cuvettes are not suitable for temperature jumps on this time scale, as a result of the slow kinetics of heat transfer across substances with characteristically high dielectric constants, and their use can convolute the time scale of the temperature change onto the time scale... 

Fig. 3. Assembly of microtubule protein monitored by time-resolved X-ray scattering. The projection plot shows an experiment using the EMBL instrument X33, camera length 3 m, linear position-sensitive detector with 256 channels, 256 time frames of 3 sec per run (not all shown), temperature jumps from 3 to 37 °C and back (arrows). Note the increase in central scatter during assembly and the change in side maxima. The side maximum of the cold solution is due to rings, that of the warm solution is due to microtubules. From [11]...

Fig. 7. Projection plot of the X-ray scattering from a solution of oscillating microtubules, showing the X-ray intensity (S I(S), z-axis) as a function of scattering vector (S = 2 sin 9/lambda, x-axis) and time (y-axis, 3 sec scan interval). Microtubule protein, 32 mg/ml. The central scatter (left) indicates overall assembly, the subsidiary maximum arises from microtubules. The temperature jump is at time zero. The periodicity of the fluctuations is about 2 min. The final state (after disappearance of the oscillations) is dominated by the scattering from oligomers. The scattering curves here and in Fig. 8 have been smoothed by cubic splines. From [16]...

Heat-shock proteins A group of Chapero-nins that accumulates in a cell after it has been subjected to a sudden temperature jump or other stress. They are thought to help deal with the accumulation of improperly folded or assembled proteins in stressed cells. 

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