Global ETD Search
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Showing 1 to 20 of 43 for “"Tryptophan Fluorescence"”.
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Mapping RNA Binding Surfaces on Hfq Using Tryptophan Fluorescence Quenching
… more complex RNA sequences interact with Hfq, a tryptophan fluorescence quenching (TFQ) assay has been developed. Here it is presented that TFQ can correctly identify the binding face for two control sequences, A15 and U6, using the E. coli, S. aureus and L. monocytogenes Hfq homologues. Using …
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Mechanism of the efficient quenching of tryptophan fluorescence in human gamma crystallin
Quenching of the fluorescence of buried tryptophans (Trps) is an important reporter of protein conformation. Human [gamma]D-crystallin (H[gamma]D-Crys) and human [gamma]S-crystallin (H[gamma]S-Crys) are both very stable eye lens protein that must remain soluble and folded throughout the human …
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Direct observation of fast protein folding: Distinct nanosecond and microsecond events in the folding of apomyoglobin
… are followed by a new temperature-jump fluorescence technique on a nanosecond to 0.5 millisecond time scale in vitro. Collapse to a compact state is complete in under 20 microseconds under strongly-nativizing conditions. The intrinsic tryptophan fluorescence (residue 14 in the A alpha …
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Effects of silver nanoparticles on photochemical processes focusing on luminol chemiluminescence
… or quenching the photochemical processes of tryptophan fluorescence, a ruthenium complex decay constant and chemiluminescence of luminol and ferricyanide, were studied. The tryptophan fluorescence was slightly enhanced by smaller nanoparticles and showed slight quenching in the presence of …
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Fluorescence Depolarization Study of Internal Tryptophan Mobility in Hydrated Azurin Films
… dynamics was investigated using steady state fluorescence depolarization on azurin, which has a single tryptophan residue well-buried in the hydrophobic interior. Azurin was imbedded in a thin, solid, water-permeable polymer film. This procedure inhibited whole-protein motion while allowing …
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Fluorenscence depolarization study of internal tryptophan mobility in hydrated azurin films
… dynamics was investigated using steady state fluorescence depolarization on azurin, which has a single tryptophan residue well-buried in the hydrophobic interior. Azurin was imbedded in a thin, solid, water-permeable polymer film. This procedure inhibited whole-protein motion while allowing …
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Mutational Analysis of HIV-1 Nucleocapsid Protein and Methods Development for Aptamer Discovery
… signal in HIV-1, SL3 RNA, were measured using tryptophan fluorescence titration assay and/or isothermal titration calorimetry (ITC) assay. Most mutants show tolerance of the mutation but some mutants, including F16A, I24A and K14E-E21K, suffered moderate to significant loss of affinity for SL3 …
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Interactions of ATP, ADP and magnesium ion with rubisco activase and their effects on rubisco activation
… complex also induced a transient increase in the tryptophan fluorescence of spinach rubisco activase. The kinetics of the fluorescence change was similar to that of ATP hydrolysis. ADP was a competitive inhibitor of the ATP induced fluorescence enhancement. This complex exhibited a higher …
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Probing Structural Differences of Recombinant Prion Isoforms Using Fluorescence Spectroscopy
… of prion diseases. In this study, six single-tryptophan mutants of recombinant PrP were expressed, purified, and refolded into PrPC or two misfolded isoforms of prion, PrPb and PrPF. Solvent accessibilities of the six tryptophan residues were probed among the three isoforms using various …
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Probing Structural Differences of Recombinant Prion Isoforms Using Fluorescence Spectroscopy
… of prion diseases. In this study, six single-tryptophan mutants of recombinant PrP were expressed, purified, and refolded into PrPC or two misfolded isoforms of prion, PrPb and PrPF. Solvent accessibilities of the six tryptophan residues were probed among the three isoforms using various …
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Investigation of the dynamics and conformational changes of the U1A protein
… RNA complex using laser T-jump and stopped-flow fluorescence methods. Analysis of the kinetic data suggested three phases of dissociation with two intermediate states. Chapter 4 is a follow up study of chapters 2 and 3 to further investigate helix C dynamics. The experimental design makes use of …
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Dynamics of oxygen penetration and diffusion into horse skeletal myoglobin revealed by quenching of zinc protoporphyrin IX fluorescence
Oxygen quenching of tryptophan fluorescence in a number of globular proteins provided some of the early experimental evidence for conformational fluctuations in proteins. Gratton et al. (Biophysical J. 1984. 45:789-794) proposed a sequential two step model called the dynamic model for oxygen …
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Studies of Protein-Protein and Protein-Water Interactions by Small Angle X-Ray Scattering, Terahertz Spectroscopy, ASMOS, And Computer Simulation
… are compared to small angle X-ray scattering, tryptophan fluorescence, and circular dichroism results. We propose that KITA monitors the rearrangement of hydrogen bonding during secondary structure formation. Finally, we present development of the automated single molecule operating system …
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Characterization of the unfolding, refolding, and aggregation pathways of two protein implicated in cataractogenesis : human gamma D and human gamma S crystallin
… at neutral pH and 37⁰C, using intrinsic tryptophan fluorescence to monitor in vitro folding. Equilibrium unfolding and refolding experiments with GdnHCl showed unfolded protein is more fluorescent than its native counter-part despite the absence of metal or ion-tryptophan interactions in …
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The molecular bases of tryptophan replacement effects in RecA: A biochemical and biophysical characterization of single- and null- tryptophan mutant Escherichia coli RecA proteins
… exchange processes on a relevant time scale. Fluorescence spectroscopy of the RecA protein has been used to elucidate some of the obscure intermediates involved in the strand exchange process. The rapid timescale of changes in tryptophan fluorescence and the precise placement of fluorescence …
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Biophysical characterization of KO513, a protein expressed in human invasive glioblastoma
… expression and purification of K0513. Using tryptophan fluorescence assay and limited proteolysis, nucleotides were found to have no significant effect on the tertiary structural conformation of K0513. Pull down assay shows promising interactors of K0513 from fibrosarcoma cell line; future …
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Characterization of the Reaction Cycle of MJ0796: A Model Archaeal Adenosine Triphosphate-Binding Cassette Transporter Nucleotide Binding Domain
… mutant mixtures were further analyzed using tryptophan fluorescence emission and anisotropy. Mixing experiments were performed using a full transporter system, the lipoprotein release machinery from Escherichia coli. A modified ABC transporter reaction cycle is presented.
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Kinetics and specificity of nicotinamide nucleotide binding to the dIII component of transhydrogenase from Rhodospirillum Rubrum
… and occluded conformations. Enzyme assays and tryptophan fluorescence experiments using apo-dIII in complex with dI revealed two features: Firstly, the binding of NADP(H) to dIII is very slow and is probably limited by the conversion from the occluded to the open conformation. Since the switch …
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Gene cloning, adjustable expression and site-directed mutagenesis of Escherichia coli adenylate kinase
… X-ray studies were independently changed to tryptophan and other amino acids. Both enzyme kinetics and tryptophan fluorescence data suggest that the phe86 is located in the active site of the enzyme and primarily involved in the binding of AMP, while tyr133 plays more a structural role rather …
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Nucleotide Inhibition of Glyoxalase II
… distinguishable after "de-sensitization". Tryptophan fluorescence studies of the two enzyme preparations suggest that a subtle conformational change in the enzyme has occurred during de-sensitization. We have also observed that Glo-II-i is "resensitized" to nucleotide inhibition after …
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