Time resolved fluorescence of aqueous tryptophan

1978 ◽  
Vol 56 (5) ◽  
pp. 743-745 ◽  
Author(s):  
D. M. Rayner ◽  
A. G. Szabo
Keyword(s):  
Exponential Decay ◽  
Emission Spectra ◽  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Decay Function ◽  
Time Resolved ◽  
Exponential Decay Function

The fluorescence decay of aqueous tryptophan is shown to be described by a two exponential decay function whose components have life-times of 3.14 ns and 0.51 ns. These components are assigned as the solvent equilibrated 1La and 1Lb, states respectively. The time-resolved emission spectra are presented and can be resolved into two spectra with λmax at 350 nm and 335 nm corresponding to these two states.

Concentration and Temperature Dependence of Laurdan Fluorescence in Glycerol

2003 ◽  
Vol 58 (9-10) ◽  
pp. 581-588 ◽  
Author(s):  
K. A. Kozyra ◽  
J. R. Heldt ◽  
J. Heldt ◽  
M. Engelkec ◽  
H. A. Diehl
Keyword(s):  
Steady State ◽  
Time Distribution ◽  
Emission Spectra ◽  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Fluorescence Measurements ◽  
Fluorescence Decay Time ◽  
Laurdan Fluorescence ◽  
Vibrational Equilibrium

Steady-state and time-resolved fluorescence measurements have been performed on Laurdan, dissolved in viscous glycerol, as functions of temperature and concentration. The results indicate spectral heterogeneity of the Laurdan solution. The fluorescence decay time distribution is attributed to radiative deexcitation of spatial conformational forms of locally excited (LE) and charge transfer (CT) states, the S1(CT)EQ state being in thermodynamic and vibrational equilibrium. The lifetimes and contributions of the different fluorescence modes depend on concentration and temperature. The excitation and emission spectra show discontinuous changes with increase of the Laurdan concentration.We suppose that the observed changes are caused by the formation of Laurdan micelle aggregates.

Tyrosine and tyrosinate fluorescence of S-100b. A time-resolved nanosecond fluorescence study. The effect of pH, Ca(II), and Zn(II)

1989 ◽  
Vol 67 (4-5) ◽  
pp. 179-186 ◽  
Author(s):  
R. J. Turner ◽  
R. S. Roche ◽  
R. S. Mani ◽  
C. M. Kay
Keyword(s):  
Metal Ion ◽  
Tertiary Structure ◽  
Emission Spectra ◽  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Fluorescence Study ◽  
Time Resolved ◽  
Effect Of Ph ◽  
Class A ◽  
Long Lifetime

The properties of the tyrosine and tyrosinate emissions from brain S-100b have been studied by nanosecond time-resolved fluorescence at emission wavelengths in the range 305 to 365 nm. The effect of pH on the fluorescence has been studied at pH 6.5, 7.5, and 8.5 for the Ca(II) apo and holo forms of the protein, and for the apo and holo forms in the presence and absence of Zn(II) at pH 7.5. The fluorescence decay is biexponential at pH 8.5 and triexponential at pH 6.5 and 7.5. The three components of the decay have wavelength and metal ion dependent lifetimes in the ranges 0.06 to 1.05 ns, 0.49 to 3.76 ns, and 3.60 to 14.5 ns. The observation of a long lifetime component at wavelengths characteristic of emission from tyrosinate suggests that in class A proteins this may be a useful diagnostic of the environment of tyrosine in their native structures. The time-resolved emission spectra provide evidence for efficient, subnanosecond protolysis of the excited state of the single tyrosine (Tyr17) under all conditions studied except in 6 M guanidium chloride in which the protein shows only emission from tyrosine (λem 305 nm), suggesting that the tyrosinate emission is a property of the tertiary structure of the native protein. The Zn(II)-dependence of the fluorescence is fully consistent with the earlier suggestion that Tyr17 is near the Zn(II) binding site and remote from the high affinity Ca(II) binding site.Key words: S-100b, time-resolved fluorescence, tyrosinate fluorescence, time-resolved emission spectra.

scholarly journals Architecture of Polyglutamine-containing Fibrils from Time-resolved Fluorescence Decay

2014 ◽  
Vol 289 (39) ◽  
pp. 26817-26828 ◽  
Author(s):  
Christoph Röthlein ◽  
Markus S. Miettinen ◽  
Tejas Borwankar ◽  
Jörg Bürger ◽  
Thorsten Mielke ◽  
...  
Keyword(s):  
Fluorescence Decay ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Maximum likelihood method for the analysis of time-resolved fluorescence decay curves

1991 ◽  
Vol 20 (5) ◽  
pp. 247-262 ◽  
Author(s):  
?eljko Bajzer ◽  
Terry M. Therneau ◽  
Joseph C. Sharp ◽  
Franklin G. Prendergast
Keyword(s):  
Maximum Likelihood ◽  
Maximum Likelihood Method ◽  
Fluorescence Decay ◽  
Likelihood Method ◽  
Time Resolved Fluorescence ◽  
Time Resolved

Time-resolved Fluorescence Decay Study of Hematoporphyrin Derivative

1991 ◽  
Vol 8 (1) ◽  
pp. 40-43 ◽  
Author(s):  
Liu Wenqing ◽  
Xia Yuxing ◽  
Liu Songhao ◽  
Ramponi R ◽  
Cubeddu R
Keyword(s):  
Fluorescence Decay ◽  
Hematoporphyrin Derivative ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Decay Study

scholarly journals Interaction of heparin with internally quenched fluorogenic peptides derived from heparin-binding consensus sequences, kallistatin and anti-thrombin III

2002 ◽  
Vol 366 (2) ◽  
pp. 435-446 ◽  
Author(s):  
Daniel C. PIMENTA ◽  
Iseli L. NANTES ◽  
Eduardo S. de SOUZA ◽  
Bernard Le BONNIEC ◽  
Amando S. ITO ◽  
...  
Keyword(s):  
Binding Sites ◽  
Fluorescence Decay ◽  
Heparin Binding ◽  
Cd Spectra ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Kd Values ◽  
Donor Acceptor ◽  
Peptide Complexes ◽  
Α Helix

Internally quenched fluorogenic (IQF) peptides bearing the fluorescence donor/acceptor pair o-aminobenzoic acid (Abz)/N-(2,4-dinitrophenyl)ethylenediamine (EDDnp) at N- and C-terminal ends were synthesized containing heparin-binding sites from the human serpins kallistatin and antithrombin, as well as consensus heparin-binding sequences (Cardin clusters). The dissociation constant (Kd), as well as the stoichiometry for the heparin–peptide complexes, was determined directly by measuring the decrease in fluorescence of the peptide solution. Experimental procedures were as sensitive as those used to follow the fluorescence change of tryptophan in heparin-binding proteins. The conformation of the peptides and the heparin–peptide complexes were obtained from measurements of time-resolved fluorescence decay and CD spectra. Kallistatin (Arg300–Pro319)-derived peptide (HC2) and one derived from antithrombin III helix D [(AT3D), corresponding to Ser112–Lys139], which are the heparin-binding sites in these serpins, showed significant affinity for 4500Da heparin, for which Kd values were 17nM and 100nM respectively. The CD spectra of the heparin–HC2 peptide complex did not show any significant α-helix content, different from the situation with peptide AT3D, for which complex-formation with heparin resulted in 24% α-helix content. The end-to-end distance distribution and the time-resolved fluorescence-decay measurements agree with the CD spectra and Kd values. The synthetic α-methyl glycoside pentasaccharide AGA∗IAM (where A represents N,6-O-sulphated α-d-glucosamine; G, β-d-glucuronic acid; A∗, N,3,6-O-sulphated α-d-glucosamine; I, 2-O-sulphated α-l-iduronic acid; and AM, α-methyl glycoside of A) also binds to AT3D and other consensus heparin-binding sequences, although with lower affinity. The interaction of IQF peptides with 4500Da heparin was displaced by protamine. In conclusion, IQF peptides containing Abz/EDDnp as the donor/acceptor fluorescence pair are very promising tools for structure–activity relationship studies on heparin–peptide complexes, as well as for the development of new peptides as heparin reversal-effect compounds.

scholarly journals Retinal Degeneration in Choroideremia follows an Exponential Decay Function

Ophthalmology ◽  
2018 ◽  
Vol 125 (7) ◽  
pp. 1122-1124 ◽  
Author(s):  
James W. Aylward ◽  
Kanmin Xue ◽  
Maria I. Patrício ◽  
Jasleen K. Jolly ◽  
Jonathan C. Wood ◽  
...  
Keyword(s):  
Retinal Degeneration ◽  
Exponential Decay ◽  
Decay Function ◽  
Exponential Decay Function

scholarly journals Mechanisms of fluorescence decays of colloidal CdSe–CdS/ZnS quantum dots unraveled by time-resolved fluorescence measurement

2015 ◽  
Vol 17 (41) ◽  
pp. 27588-27595 ◽  
Author(s):  
Hao Xu ◽  
Volodymyr Chmyrov ◽  
Jerker Widengren ◽  
Hjalmar Brismar ◽  
Ying Fu
Keyword(s):  
Quantum Dots ◽  
Radiative Recombination ◽  
Energy Relaxation ◽  
Fluorescence Decay ◽  
Fluorescence Measurement ◽  
Time Resolved Fluorescence ◽  
Time Resolved ◽  
Decay Spectrum

The fluorescence decay spectrum of colloidal CdSe-based quantum dots is characterized by energy relaxation and radiative recombination of photoexcited excitons.

scholarly journals Experimental study of the moisture content influence on CH4 adsorption and deformation characteristics of cylindrical bituminous coal core

2018 ◽  
Vol 36 (7-8) ◽  
pp. 1512-1537 ◽  
Author(s):  
Dingyi Hao ◽  
Lei Zhang ◽  
Mingxue Li ◽  
Shihao Tu ◽  
Cun Zhang ◽  
...  
Keyword(s):  
Moisture Content ◽  
Adsorption Capacity ◽  
Exponential Decay ◽  
Coal Mine ◽  
Bituminous Coal ◽  
Gas Adsorption ◽  
Decay Function ◽  
Exponential Decay Function ◽  
Adsorption Deformation ◽  
Original Moisture

Moisture content in coal is an important factor affecting the coal seam gas extraction. It directly affects the storage and flow of gas in bituminous coal. In this paper, the cylindrical bituminous coal cores of Xutuan coal mine in Huaibei coal mine group were studied as experimental objects, using the laboratory self-designed experimental device Gas Adsorption and Strain Testing Apparatus system. The influence of the bituminous coal moisture content on gas adsorption characteristics was studied. Drying experiments of coal samples showed that they lose the original moisture content following the exponential decay function of time. At wetting, the saturated moisture content in coal samples increased following the Exponential Association function of time. The experimental results show that the average original moisture content and average saturated moisture content of raw coal samples are 1.3 and 2.4%, respectively. On this basis, the gas adsorption experiments on samples with different moisture contents under different gas pressures were carried out. With the moisture content increase, the gas adsorption capacity and saturation value decreased and the decrease rate gradually reduced. The single exponential decay function describes the gas adsorption capacity dependence on moisture content. Moisture content also affects the adsorption deformation of bituminous coal. At high moisture content, the adsorption deformation of bituminous coal is less.

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