Journal ArticleDOI
Exposure of tryptophanyl residues in proteins. Quantitative determination by fluorescence quenching studies.
TLDR
The value of this probing technique lies in its ability to sense not only the steady-state exposure of a residue in a protein, but also its dynamic exposure.Abstract:
Acrylamide is an efficient quencher of tryptophanyl fluorescence which we report to be very discriminating in sensing the degree of exposure of this residue in proteins. The quenching reaction involves physical contact between the quencher and an excited indole ring, and can be kinetically described in terms of a collisional and a static component. The rate constant for the collisional component is a kinetic measure of the exposure of a residue in a protein, and values ranging from 4 X 10(9) M-1 S-1 for the fully exposed tryptophan in the polypeptide, adrenocorticotropin, to less than 5 X 10(8) M-1 S-1 for the buried residue in azurin have been found. Static quenching is readily detected in proteins that are denatured, or contain only a single fluorophor. Quenching patterns for most multi-tryptophan containing proteins are difficult to analyze precisely, but qualitative information can, nevertheless, be extracted. Applications of this probing technique for monitoring protein conformational changes, such as the acid-induced expansion of human serum albumin, and inhibitor binding to enzymes, are presented. The value of this method lies in its ability to sense not only the steady-state exposure of a residue in a protein, but also its dynamic exposure.read more
Citations
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Dynamics of folded proteins
TL;DR: The dynamics of a folded globular protein have been studied by solving the equations of motion for the atoms with an empirical potential energy function and suggest that the protein interior is fluid-like in that the local atom motions have a diffusional character.
Journal ArticleDOI
Fluorescence quenching studies with proteins.
TL;DR: A review of the use of the technique of solute fluorescence quenching to study the structure and dynamics of proteins and a number of factors are discussed that must be considered in analyzing such data.
Journal ArticleDOI
The internal dynamics of globular proteins.
Martin Karplus,J. A. McCammon +1 more
TL;DR: The Internal Dynamics of Globular Protein (IDGP) as mentioned in this paper is a well-known model for the internal dynamics of protein structures and its dynamics in the context of protein synthesis.
References
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Reaction of N-bromosuccinimide with lysozyme.
TL;DR: The lack of specificity of the reaction of N-bromosuccinimide with respect to tryptophan groups of lysozyme, the induction of a conformational change on reaction and the lack of correspondence of spectral and amino acid analysis data suggests that caution must be exercised in the use of N’Bromosucinimides as a reagent for determining the extent of ‘exposure’ of side chains of native proteins.
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Solution topography of proteins by charge transfer. Model complexes, ribonuclease, and lysozyme.
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Exciplexes and the fluorescence of staphylococcus aureus endonuclease
TL;DR: The absorption spectrum and both of the fluorescence spectra indicate that the tryptophan, even in the high‐temperature state, is in an environment with a low dielectric constant.