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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Structure of DNA-RecA complexes studied by residue differential linear dichroism and fluorescence spectroscopy for a genetically engineered RecA protein
TL;DR: The fluorescence quenching results indicate that the protein region of Trp291 is not involved in the binding of DNA, indicating similar structures of the protein fibres in the complexes with single-stranded and double-Stranded DNA.
Journal ArticleDOI
The role of aromatic side chain residues in micelle binding by pancreatic colipase. Fluorescence studies of the porcine and equine proteins
TL;DR: The emission maximum of horse colipase at 345 nm indicates a solvent-accessible tryptophan residue which becomes less so on binding of micelles, and the data are consistent with a direct insertion of dansyl-NH-tyrosine-55 into the micelle.
Journal ArticleDOI
Elucidation of the Interaction Mechanism with Liposomes of gH625-Peptide Functionalized Dendrimers
Annarita Falanga,Rossella Tarallo,Thomas Carberry,Massimiliano Galdiero,Marcus Weck,Stefania Galdiero +5 more
TL;DR: The affinity for the membrane bilayer is very high and the interaction between the peptide-dendrimer and liposomes took place without evidence of pore formation, suggesting that the presented peptidodendrimeric scaffold may be a promising material for efficient drug delivery.
Journal ArticleDOI
Human islet amyloid polypeptide (hIAPP) aggregation in type 2 diabetes: Correlation between intrinsic physicochemical properties of hIAPP aggregates and their cytotoxicity.
Ali Chaari,Moncef M. Ladjimi +1 more
TL;DR: The results indicate that despite the method used to study hIAPP aggregation, the obtained curve is easily well fitted in a sigmoidal curve but with some differences, consistent with a model in which the exposure of hydrophobic surfaces and the small size of aggregates formed during the early stage of the process are crucial for their cytotoxicity.
Journal ArticleDOI
Interaction between Ester-Type Tea Catechins and Neutrophil Gelatinase-Associated Lipocalin: Inhibitory Mechanism
TL;DR: The inhibitory mechanism of ETC against NGAL supports its potential use in attenuation of neurotoxicity and suggests that ETC with more catechol moieties has a stronger binding capacity with NGAL especially in the presence of Fe3+.
References
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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.