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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Biochemical characterisation of a hydrophobic ligand binding protein from the tapeworm Hymenolepis diminuta
TL;DR: The cestode Hymenolepis diminuta contains an abundant, cytoplasmic, hydrophobic ligand, binding protein (H-HLBP), which binds a range of anthelmintics, with K(D) values in the nM range, which may be important in determining drug specificity and site of action.
Journal ArticleDOI
The uncoupling protein from brown-adipose-tissue mitochondria. Chymotrypsin-induced structural and functional modifications.
TL;DR: In this paper, the authors used fluorescence-quenching-resolved spectroscopy (FQRS) to determine the locations of two tryptophan residues in brown adipose tissue.
Journal ArticleDOI
Structure-Based Identification of Potential Drugs Against FmtA of Staphylococcus aureus: Virtual Screening, Molecular Dynamics, MM-GBSA, and QM/MM
Vikram L. Dalal,Poonam Dhankhar,Vishakha Singh,Gaddy Rakhaminov,Dasantila Golemi-Kotra,Pravindra Kumar +5 more
TL;DR: In this paper, a virtual screening of drug molecules against the crystal structure of FmtA was performed and the binding affinities of top three molecules (ofloxacin, roflumilast, and furazolidone) were predicted using molecular docking.
Journal ArticleDOI
Rigidifying flexible sites: An approach to improve stability of chondroitinase ABC I.
TL;DR: It is demonstrated that rigidifying flexible residues can be considered as a possible approach to increase the stability of the protein.
Journal ArticleDOI
Towards recombinantly produced milk proteins: Physicochemical and emulsifying properties of engineered whey protein beta-lactoglobulin variants
Julia K. Keppler,Julia K. Keppler,Anja Heyse,Eva Scheidler,Maximilian J. Uttinger,Laura Fitzner,Uwe Jandt,Timon R. Heyn,Vanessa Lautenbach,J.I. Loch,Jonas Lohr,Helena Kieserling,Gabriele Günther,Elena Kempf,Jan Hendrik Grosch,Krzysztof Lewiński,Dieter Jahn,Christian Lübbert,Wolfgang Peukert,Ulrich Kulozik,Stephan Drusch,Rainer Krull,Karin Schwarz,Rebekka Biedendieck +23 more
TL;DR: Two recombinant beta-lactoglobulin (BLG) B variants were produced in E. coli and production/isolation resulted in native BLG without post-translational modifications, showing similar emulsifying properties to natural BLGs.
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.