Data di Pubblicazione:
2003
Citazione:
Kinetics of Intramolecular Contact Formation in a Denatured Protein / Marco Buscaglia, Benjamin Schuler, Lisa J. Lapidus, William A. Eaton, James Hofrichter. - In: JOURNAL OF MOLECULAR BIOLOGY. - ISSN 0022-2836. - 332:1(2003), pp. 9-12.
Abstract:
Quenching of the triplet state of tryptophan by cysteine has provided a
new tool for measuring the rate of forming a specific intramolecular contact
in disordered polypeptides. Here, we use this technique to investigate
contact formation in the denatured state of CspTm, a small cold-shock
protein from Thermotoga maritima, engineered to contain a single tryptophan
residue (W29) and a single cysteine residue at the C terminus
(C67). At all concentrations of denaturant, the decay rate of the W29
triplet of the unfolded protein is more than tenfold faster than the rate
observed for the native protein (10^4 1/s). Experiments on the unfolded
protein without the added C-terminal cysteine residue show that this faster
rate results entirely from contact quenching by C67. The quenching
rate in the unfolded state by C67 increases at concentrations of denaturant
that favor folding, indicating a compaction of the unfolded protein as
observed previously in single-molecule Forster resonance energy transfer
(FRET) experiments.
Tipologia IRIS:
01 - Articolo su periodico
Keywords:
Cold shock protein; Collapse; Triplet state quenching; Unfolded state
Elenco autori:
Marco Buscaglia, Benjamin Schuler, Lisa J. Lapidus, William A. Eaton, James Hofrichter
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