Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    End-to-end diffusion and distance distributions of flexible donor-acceptor systems observed by intramolecular energy transfer and frequency-domain fluorometry; enhanced resolution by global analysis of externally quenched and nonquenched samples (1991)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 95 (1991), S. 9654-9660 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100177a012
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Light Quenching of Fluorescence Using Time-Delayed Laser Pulses As Observed by Frequency-Domain Fluorometry (1994)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 98 (1994), S. 8886-8895 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100087a012
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Light quenching and fluorescence depolarization of rhodamine B and applications of this phenomenon to biophysics (1994)
    s.l. : American Chemical Society
    The @journal of physical chemistry 〈Washington, DC〉 98 (1994), S. 334-342 
    Details
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1021/j100052a055
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Distance distributions and dynamics of a zinc finger peptide from fluorescence resonance energy transfer measurements (1993)
    Springer
    Journal of fluorescence 3 (1993), S. 23-31 
    Details
    ISSN: 1573-4994
    Keywords: Zinc finger peptide ; distance distributions ; dynamics ; frequency-domain fluorometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Time-resolved fluorescence resonance energy transfer (FRET) measurements were used to measure distance distributions and intramolecular dynamics (site-to-site diffusion) of a 28-residue single-domain zinc finger peptide in the absence and presence of zinc ion. Energy transfer was measured between TRP14 and a N-terminal DNS group. As expected, the TRP-to-DNS distance distribution for zinc-bound peptide is shorter and narrower (R av=11.2 Å,hw=2.8 Å) than the metal-free peptide (R av=20.1 Å,hw=14.5 Å). The degree of mutual donor-to-acceptor diffusion (D) was also determined for these distributions. For zinc-bound peptide there is no detectible diffusion (D≤0.2 Å2/ns), whereas for metal-free peptide a considerable amount of motion is occurring between the donor and the acceptor (D=12 Å2/ns). These results indicate that the zinc-bound peptide folds into a unique, well-defined conformation, whereas the metal-free conformation is flexible and rapidly changing. The absence of detectible mutual site-to-site diffusion between the donor and the acceptor in the metal-bound zinc finger peptide indicates that intramolecular motion is essentially frozen out, on the FRET time scale, as a consequence of zinc coordination.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00865286
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Review of fluorescence anisotropy decay analysis by frequency-domain fluorescence spectroscopy (1993)
    Springer
    Journal of fluorescence 3 (1993), S. 103-116 
    Details
    ISSN: 1573-4994
    Keywords: Fluorescence anisotropy decays ; frequency-domain fluorescence spectroscopy ; review
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract This didactic paper summarizes the mathematical expressions needed for analysis of fluorescence anisotropy decays from polarized frequency-domain fluorescence data. The observed values are the phase angle difference between the polarized components of the emission and the modulated anisotropy, which is the ratio of the polarized and amplitude-modulated components of the emission. This procedure requires a separate measurement of the intensity decay of the total emission. The expressions are suitable for any number of exponential components in both the intensity decay and the anisotropy decay. The formalism is generalized for global analysis of anisotropy decays measured at different excitation wavelengths and for different intensity decay times as the result of quenching. Additionally, we describe the expressions required for associated anisotropy decays, that is, anisotropy decays where each correlation time is associated with a decay time present in the anisotropy decay. And finally, we present expressions appropriate for distributions of correlation times. This article should serve as a reference for researchers using frequency-domain fluorometry.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00865324
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Distance-dependent fluorescence quenching ofN-acetyl-l-tryptophanamide by acrylamide (1993)
    Springer
    Journal of fluorescence 3 (1993), S. 199-207 
    Details
    ISSN: 1573-4994
    Keywords: N-acetyl-l-tryptophanamide ; tryptophan fluorescence intensity decay ; frequency-domain fluorometry ; fluorescence spectroscopy ; distance-dependent quenching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We examined the time-dependent intensity decays ofN-acetyl-l-tryptophanamide (NATA) when collisionally quenched by acrylamide in propylene glycol over a range of temperatures. The intensity decays of NATA became increasingly heterogeneous in the presence of acrylamide. The NATA intensity decays were not consistent with the Collins-Kimball radiation boundary condition (RBC) model for quenching. The steady-state Stern-Volmer plots show significant upward curvature, and quenching of NATA by acrylamide was observed even in vitrified propylene glycol, where translational diffusion cannot occur during the lifetime of the excited state. These frequencydomain and steady-state data indicate a through-space quenching interaction between NATA and acrylamide, and the results are consistent with a rate constant for quenching that depends exponentially on the fluorophore-quencher separation distance. The exponential distance-dependent rate of quenching also explains the upward curvature of the Stern-Volmer plot, and the steady-state data aid in determining the interaction distance between NATA and acrylamide. These results suggest that the distance-dependent quenching rates need to be considered in the interpretation of acrylamide quenching of proteins.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00862743
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Conformational differences of oxytocin and vasopressin as observed by fluorescence anisotropy decays and transient effects in collisional quenching of tyrosine fluorescence (1991)
    Springer
    Journal of fluorescence 1 (1991), S. 163-176 
    Details
    ISSN: 1573-4994
    Keywords: Oxytocin ; vasopressin ; fluorescence intensity ; fluorescence anisotropy decays ; tyrosine fluorescence ; collisional quenching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We used gigahertz frequency-domain fluorometry to examine the tyrosyl fluorescence intensity and anisotropy decays of the single-tyrosine cyclic peptide hormones oxytocin and vasopressin. Acrylamide quenching and a distance-dependent quenching model for collisional quenching were used to evaluate the extent of tyrosyl exposure to the quencher and to provide increased resolution of the picosecond anisotropy decays. Analysis of the intensity decays using a lifetime distribution model shows different distributions for oxytocin and vasopressin. We found that the tyrosyl fluorescence of lysine-vasopressin, as revealed both by the lifetime Stern-Volmer plots and from the quenching analysis, is quenched more effectively than oxytocin. ForN-acetyltyrosinamide (NATyrA), oxytocin, and lysine-vasopressin, we recovered apparent diffusion coefficients for quenching of 4.7×10−6, 0.44×10−6, and 4.3×10−6 cm2/s, respectively, the lower value for oxytocin suggesting a shielded environment for its tyrosyl residue. Tyrosyl anisotropy decays were recovered by global analysis of progressively quenched samples. Compared with oxytocin, vasopressin displayed a longer correlation time for overall rotational diffusion and a higher amplitude for picosecond segmented motions of its tyrosyl residue. All the data are consistent with a more extended and flexible solution structure for vasopressin than for oxytocin.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00865363
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Emerging biomedical and advanced applications of time-resolved fluorescence spectroscopy (1994)
    Springer
    Journal of fluorescence 4 (1994), S. 117-136 
    Details
    ISSN: 1573-4994
    Keywords: Time-resolved fluorescence spectroscopy ; two photon-induced fluorescence ; light quenching
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Time-resolved fluorescence spectroscopy is presently regarded as a research tool in biochemistry, biophysics, and chemical physics. Advances in laser technology, the development of long-wavelength probes, and the use of lifetime-based methods, are resulting in the rapid migration of timeresolved fluorescence to the clinical chemistry lab, the patient's bedside, and even to the doctor's office and home health care. Additionally, time-resolved imaging is now a reality in fluorescence microscopy and will provide chemical imaging of a variety of intracellular analytes and/or cellular phenomena. Future horizons of state-of-the-art spectroscopy are also described. Two photon-induced fluorescence provides an increased information content to time-resolved data. Two photoninduced fluorescence, combined with fluorescence microscopy and time-resolved imaging, promises to provide detailed three-dimensional chemical imaging of cells. Additionally, it has recently been demonstrated that the pulses from modern picosecond lasers can be used to quench and/or modify the excited-state population by stimulated emission since the stimulated photons are directed along the quenching beam and are not observed. The phenomenon of light quenching should allow a new class of multipulse time-resolved fluorescence experiments, in which the excited-state population is modified by additional pulses to provide highly oriented systems.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01876666
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Quenching of fluorescence by light: A new method to control the excited-state lifetimes and orientations of fluorophores (1994)
    Springer
    Journal of fluorescence 4 (1994), S. 103-109 
    Details
    ISSN: 1573-4994
    Keywords: Light quenching ; excited-state lifetime ; fluorophores
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract We report steady-state and time-resolved studies of quenching of fluorescence by light i.e. “light quenching.” The dyes rhodamine B (RhB) and 4-dicyanomethylene-2-methyl-6(p-dimethamino)-4H-pyrane (DCM) were excited in the anti-Stokes region from 560 to 615 nm. At a high illumination power the intensities of DCM and RhB were sublinear with incident power, an effect we believe is due to stimulated emission, andnot ground-state depopulation. The extent of light quenching was proportional to the amplitude of the emission spectrum at the incident wavelength, as expected for light-stimulated decay from the excited state. Control measurements at a decreased average illumination power, and in solvents of various viscosities, indicated that the effect was not due to undesired photochemical processes. Importantly, the frequency-domain intensity decays remained single exponentials, and the lifetimes were unchanged with light quenching, which suggests that the effect was not due to heating or other photochemical effects. These results are consistent with a quenching process which occurs within the quenching pulse. Importantly, as expected for light quenching with a single pulsed laser beam, the time 0 anisotropies of RhB and DCM were decreased due to orientation-dependent quenching of the excited-state population. In closing we discuss some possible future applications of light quenching to studies of dynamic processes.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01876664
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Distance-dependent quenching of Nile Blue fluorescence byN,N-diethylaniline observed by frequency-domain fluorometry (1996)
    Springer
    Journal of fluorescence 6 (1996), S. 187-194 
    Details
    ISSN: 1573-4994
    Keywords: Fluorescence ; quenching ; electron transfer ; time-resolved fluorescence ; frequency-domain fluorometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Fluorescence quenching of Nile Blue by amines is thought to be due to electron transfer to the excited dye molecule from the amine electron donor. We used electron transfer quenching of Nile blue byN,N-diethylaniline in propylene glycol as a model system for an interaction which depends exponentially on distance. We investigated the time dependence of the presumed distance-dependent process using gigahertz harmonic-content frequency-domain fluorometry. The frequency-domain data and the steady-state quantum yield were analyzed globally based on either the Smoluchowski-Collins-Kimball radiation boundary condition (RBC) model or the distancedependent quenching (DDQ) model, in which the rate of quenching depends exponentially on the flourophore-quencher distance. We performed a global analysis which included both the frequencydomain time-resolved decays and the steady-state intensities. The latter were found to be particularly sensitive to the model and parameter values. The data cannot be satisfactorily analyzed using the RBC model for quenching. The analysis shows the excellent agreement of the DDQ model with the experimental data, supporting the applicability of the DDQ model to describe the quenching by the electron transfer process, which depends exponentially on the donor-acceptor distance.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00732821
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...