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
More filters
Journal ArticleDOI
Flash photolysis of bovine serum albumin: identification and decay kinetics of transient intermediates
TL;DR: In this paper, the triplet of the single indole side chain of human serum albumin was detected at room temperature using the method of flash photolysis, and it was found to decay exponentially for over a factor of ten with a lifetime τ 0.5 ms.
Journal ArticleDOI
Nanosecond dynamics of influenza A/M2TM and an amantadine resistant mutant probed by time-dependent red shifts of a native tryptophan
TL;DR: The influenza A M2 proton channel, containing a tryptophan residue that serves as an essential part of the proton conduction pathway, achieves a water-like stabilization over a 25 nanosecond time scale, slower than that of bulk water, but sufficiently rapid to contribute to stabilization of charge as protons diffuse through the channel.
Journal ArticleDOI
Investigation of conformational changes in yeast enolase using dynamic fluorescence and steady state quenching measurements
TL;DR: Under conditions of catalysis, the correlation time decreases 25%, though the sedimentation constant does not change (Holleman, 1973), and the conformational metal ion effect suggests a more compact molecule.
Journal ArticleDOI
Circular dichroism and fluorescence studies on five mutant forms of protein synthesis initiation factor eIF-4E, from the yeast Saccharomyces cerevisiae
TL;DR: A preliminary attempt has been made to correlate the spectroscopic data with the known biological importance of the individual Trp residues, and different quantum yields and reduced m7GpppG‐induced quenching are shown.
Colchicine binding site determination in human serum albumin in the presence of aspirin using multi-spectroscopic and zeta-potential techniques.
TL;DR: Results obtained from analysis of fluorescence spectra indicated that colchicine in the presence of ASA had a strong ability to quench the intrinsic fluorescence of HSA through a static quenching procedure.
References
More filters
Journal ArticleDOI
The interpretation of protein structures: estimation of static accessibility.
B. Lee,Frederic M. Richards +1 more
TL;DR: The accessibility of atoms in the twenty common amino acids in model tripeptides of the type Ala-X-Ala are given for defined conformation and the larger non-polar amino acids tend to be more “buried” in the native form of all three proteins.
Journal ArticleDOI
Removal of Fatty Acids from Serum Albumin by Charcoal Treatment
TL;DR: Fluorescence spectra of human serum albumin samples indicated that impurities are sometimes present which can be removed by charcoal at neutral pH, and acid-charcoal treatment is a much more rapid method of removing lipid impurities than other methods previously described.
Journal ArticleDOI
Solute perturbation of protein fluorescence. The quenching of the tryptophyl fluorescence of model compounds and of lysozyme by iodide ion.
TL;DR: The results of the model compound study provide evidence for a mechanism that follows the classical Stern-Volmer law (1919), predominantly involving collisional quenching, and illustrate the importance of local charge and solvent viscosity.