Several methods are used to detect amide hydrogen exchange including NMR, matrix-assisted laser desorption/ionization time-of-flight-mass spectrometry, and electrospray ionization mass spectrometry. Second, several coexisting conformations can be observed at the same time, which allowed the detection of the correlated exchange at 42 °C. In NMR an average exchange rate is determined. Soc. Trans. 24, 274-279 ↵ Wang, L., Pan, H., and Smith, D. L. (2002) Mol. Furthermore, our data explain why σ32 constitutes a substrate for Hsp70 chaperones, which otherwise recognize unfolded proteins. This Bike Shows The Support for Those Who Protect and Serve.
The exchange reaction was stopped by pH shift to 2.2 and temperature shift to 0 °C. Under these conditions amide hydrogens exchange on average with half-lives of 60-90 min (14), whereas deuterons incorporated into the side chains and amino/carboxyl termini rapidly exchange back to protium. Because k-1 is at least five-times smaller than the intrinsic chemical exchange rate k2 (for 95% exchange to happen before refolding occurs), k1/k-1 ≤ k1/(k2/5) and the resulting|ΔG| ≤ |R × T × ln(k1/(k2/5))| with R being the universal gas constant and T the absolute temperature. Выжившему придется выбрать сторону в конфликте: Минитмены, Братство Стали, Подземка или Институт. Но возможно выполнить некоторый ряд квестов фракций, не испортив отношений с другими. View larger version: Fig. 1. In-line peptic digestion/rapid desalting HPLC setup. Overall Deuteron Incorporation into σ32—We analyzed the exchange kinetics of full-length σ32 and the propensity for deuterium incorporation within 99% of its primary sequence. Pricing options Plan Description Price Free 100K calls per month Free Standard 1K TPS $0.05 per 1000 calls Buy on Azure You might also be interested in Developer resources for Web Language Model API.
These data and our model show that only the N-terminal σ2 domain is tightly folded and the C-terminal half resembles an unfolded protein. Based on the secondary structure prediction program PHD, these first amino acids were unstructured, and according to our amide hydrogen exchange data solvent exposed and not involved in any secondary structure stabilizing hydrogen bonds. We therefore added them manually in an extended conformation. Taken together our data show that the σ2 domain of σ32 can act as a thermosensor, which might be important for the heat shock regulation.