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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Targeted Intracellular Delivery of Resveratrol to Glioblastoma Cells Using Apolipoprotein E-Containing Reconstituted HDL as a Nanovehicle
Sea H. Kim,Birendra Babu Adhikari,Siobanth Cruz,Michael P. Schramm,Joe A. Vinson,Vasanthy Narayanaswami +5 more
TL;DR: It is proposed that r HDL provides an ideal hydrophobic milieu to sequester resveratrol and that rHDL containing apoE3 serves as an effective “nanovehicle” to transport and deliver resver atrol to targeted intracellular sites.
Journal ArticleDOI
Steady-state and time-resolved fluorescence studies on Trichosanthes cucumerina seed lectin.
Roopa Kenoth,Musti J. Swamy +1 more
TL;DR: Steady-state and time-resolved fluorescence spectroscopic studies have been carried out on Trichosanthes cucumerina seed lectin, indicating that the Trp residues in TCSL fall into at least two groups that differ considerably in their accessibility and/or environment.
Journal ArticleDOI
The allosteric interaction between D-galactose and the Escherichia coli galactose repressor protein.
TL;DR: It is shown that both pH and galactose cause global alterations in the structure of GalR, and the beta-anomer of D-galactose is the likely form that binds to GalR.
Journal ArticleDOI
Characterization of domain-specific interaction of synthesized dye with serum proteins by spectroscopic and docking approaches along with determination of in vitro cytotoxicity and antiviral activity.
Suparna Rudra,Somnath Dasmandal,Chiranjit Patra,Biman Kumar Patel,Suvendu Paul,Ambikesh Mahapatra +5 more
TL;DR: The interaction between a synthesized dye with proteins, bovine, and human serum albumin under physiological conditions has been characterized in detail, by means of steady-state and time-resolved fluorescence, UV–vis absorption, and circular dichroism techniques.
Journal ArticleDOI
Conformational properties of human and rat apolipoprotein A-IV.
E. Dvorin,William W. Mantulin,M. F. Rohde,Antonio M. Gotto,Henry J. Pownall,Bette C. Sherrill +5 more
TL;DR: It is shown that both rat and human apoA-IV have similar secondary structure with negative maxima in the circular dichroic spectra at 222 nm and 207 nm, and no significant difference in the alpha-helical content is found from rat plasma, rat lymph, human plasma, or human lymph.
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.