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
Spectroscopic properties and stability of the neurotoxic complex Vipoxin and its components
Nicolay Genov,Pavlina Dolashka,Boris Aleksiev,Ivanka Mancheva,Kanagalaghatta R. Rajashankar,Christian Betzel +5 more
TL;DR: Investigation of the Vipoxin X-ray model showed that the three tryptophyl side chains are located in the interface region between the enzyme and the inhibitor and are completely 'exposed' in the separated components of the complex.
Journal ArticleDOI
Nano-second protein dynamics of key residue at Position 38 in catechol-O-methyltransferase system: a time-resolved fluorescence study.
Fan Liu,Jianyu Zhang +1 more
TL;DR: The comprehensive data implied the mutant W38in/Y68A with lower activity is more rigid than the "WT"-W38in, suggesting the importance of flexibility at residue 38 to maintain the optimal catalysis.
Book ChapterDOI
Light and Life
TL;DR: Light has had a significant impact on life in general, and Homo sapiens in particular, since their beginnings, and even more so in modern times as discussed by the authors, since their migration away from the equator and toward the poles.
Journal ArticleDOI
A mononuclear nickel(II) complex based on polypyridyl ligand: synthesis, characterization, and biological activity
TL;DR: In this article, the Ni(II) complex has been characterized by single-crystal analysis, IR and electronic spectra, showing that it is distorted octahedral with one o-NPIP and two acetylacetonates.
Journal ArticleDOI
Unraveling the structural basis of urea-induced unfolding of Fasciola gigantica cytosolic malate dehydrogenase
TL;DR: In this article , a two-state cooperative unfolding revealed by intrinsic tryptophan (Trp) fluorescence and CD spectroscopy was investigated for malate dehydrogenase (FgMDH) structure.
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.