| Range |
<10^–7 sec
|
| Organism |
Generic |
| Reference |
Theillet FX et al., Physicochemical properties of cells and their effects on intrinsically disordered proteins (IDPs). Chem Rev. 2014 Jul 9 114(13):6661-714. doi: 10.1021/cr400695p p.6682 left column 2nd paragraphPubMed ID24901537
|
| Primary Source |
[531] De Sancho D, Best RB. What is the time scale for α-helix nucleation? J Am Chem Soc. 2011 May 4 133(17):6809-16. doi: 10.1021/ja200834sPubMed ID21480610
|
| Method |
Primary source abstract: "Recent ultrafast spectroscopic measurements on the peptide Ac-WAAAH(+)-NH(2) were best fit by two relaxation modes on the ∼0.1-1 ns time scale, (1) apparently much faster than had previously been experimentally inferred for helix nucleation. Here, [investigators] use replica-exchange molecular dynamics simulations with an optimized all-atom protein force field (Amber ff03w) and an accurate water model (TIP4P/2005) to study the kinetics of helix formation in this peptide. [Investigators] calculate temperature-dependent microscopic rate coefficients from the simulations by treating the dynamics between helical states as a Markov process using a recently developed formalism." |
| Comments |
P.6682 left column 2nd paragraph: "In disordered proteins, side-chains display high degrees of flexibility and their time scales of motions (<10^–8 s) are faster than most diffusion controlled binding processes (>10^–7 s)(BNID 116292). The same is true for nucleation-dependent α-helix formations (<10^–7 s)(primary source)." Primary source abstract: "The fluorescence relaxation curves obtained from simulated temperature jumps are in excellent agreement with the experimentally determined results. [Investigators] find that the kinetics are multiphasic but can be approximated well by a double-exponential function. The major processes contributing to the relaxation are the shrinking of helical states at the C-terminal end and a faster re-equilibration among coil states. Despite the fast observed relaxation, the helix nucleation time is estimated from [their] model to be 20-70 ns at 300 K, with a dependence on temperature well described by Arrhenius kinetics." |
| Entered by |
Uri M |
| ID |
116307 |