Steady-state fluorescence emission

The remarkable enhancement of steady state fluorescence emission intensity and quantitative data on fluorescence quanfum yield was sequence-dependenf, being maximum wifh AT-rich DNA and alternating AT polymer (Fig. 6b). 

Hirsch, R.E., Zukin, R.S., and Nagel, R.L. (1986) Steady-state fluorescence emission from the fluorescent probe 5-iodoacetamido-fluorescein, bound to hemoglobin. Biochem. Biophys. Res. Comm. 138, 4889. 

Methods. Absorption spectra were recorded using an Hitachi model 150-20 spectrophotometer/data processor system. Uncorrected steady-state fluorescence emission spectra were recorded using a Perkin-Elmer MPF-44A spectrofluorimeter. These spectra were collected and stored using a dedicated microcomputer and then transferred to a VAX 11/780 computer for analysis. Fluorescence spectra were corrected subsequently for the response characteristics of the detector (21). Values of the fluorescence quantum yield, <) , were determined relative to either quinine bisulfate in IN H2S04 )>f =... 

Finally, a model protein bioconjugate 52 was prepared with the reactive fluorophore 50 and bovine serum albumin (BSA). The conjugate was identified spectrophotometrically and its steady state fluorescence emission spectra... 

Fig. 23 Normalized absorption spectra of the free BSA protein (1), BSA-dye 50 conjugate (2) and steady state fluorescence emission spectrum of the BSA-dye conjugate (2 )...

Figure 3. Steady-state fluorescence emission spectra for 100 /xM pyrene in sub- and supercritical C02 as a function of density. Tr = 1.02. = 337...

Figure 18. Left Schematic representation of the concept for probing different layers of water near lipid-water interfaces through anchoring hydrocarbon tails of a series of Trp-alkyl ester probes into lipids. Right Normalized steady-state fluorescence emissions from four Trp probes. Note the correlation between emission maxima and their hydrophobicity.

Figure 32. Steady-state fluorescence emission spectra of W31 in hTrx (C73S) and mutant D60G in reduced and oxidized states. For both mutants, the fluorescence intensity in reduced state is two fold of that in oxidized state. Also there is a two-fold increase in intensity as a result of the mutation of aspartate to glycine.

Steady-state fluorescence emission studies showed that these materials present a very efficient sensing behavior for hydrogen ions, metal ions such as Cu and and for the anionic nucleotides ATP, ADP, and AMP. 

In steady-state fluorescence emission studies of these systems, good agreement between the experimental and theoretically calculated energy transfer efficiencies has been observed (Table 18), which indicates that the efficiencies in these systems are predictable. This is highly desirable in designing systems with high efficiencies. 

Fig. 3. Steady state fluorescence emission spectra of CPP in three different phases cholesteric (— at 40, 60, 80 and 100°C from the...

Figure 12. Steady-state fluorescence emission of hydroxypyrene trisulfonate. Fluorescence of 20pAf hydroxypyrene trisulfonate. (A) at pH 5.0, (B) in 2M HC1, and (C) in 30pAf apomyoglobin pH 5.0. Excitation at 400 nm. Fluorescence measured in arbitrary units at identical instrumental set up.

FIGURE 2.5 Steady-state fluorescence emission spectra of a PMAA sample labeled with naphthalene and anthracene with A,ex = 290 nm at pH 10.54 (dashed line) and pH 2.0 (continuous line). [Reproduced from reference 104.]... 

The steady-state fluorescence emission of Trp 187 in annexin V shows a maximum at 325 nni, i.e., a strongly hydrophobic environment surrounds the tryptophan residue. Binding of calcium induces a shift of tlie fluorescence emission to 348 nni (Fig. 3.10) indicating that in presence of calcium the Trp residue is now exposed to a polar microenvironment. One can notice that the red shift occurs gradually with the increase of the calcium concentration (inset of Fig. 3.10). 

Figure 8.54. Steady state fluorescence emission spectra of a crystal of aj- acid glycoprotein -progesterone complex recorded at three excitation wavelengths, 295 nm (a), 300 nm (b) and 305 nm (c). The dotted lines show the spectra obtained by considering the maximum equal to the centers of gravity, 331, 331.7 and 330 nm, at Xex 295, 300 and 305 nm, respectively. The spectra were obtained with a vertically polarized excitation light. Source Albani, J. R. 1998, Journal of Fluorescence, 8, 213-224. Authorization of reprint accorded by Kluwer Academic Publishers.

Steady-state fluorescence emission spectra in a dilute solution of several solvents were obtained to study the influence of the monomer composition on the intramolecular carbazole excimer formation. The amount of excimers strongly depends on the solvent nature and the copolymer composition. 

Figure 4.14 Steady-state fluorescence emission speara of crystalline iPS obtained from gel and atactic PS film cast from chloroform at room temperature, excitation wavelength 257 nm Reprinted from Polymer, Volume 32, B. Wandelt, Correlation of photophysical parameters with conformational structure of crystalline iPS and comparison with data of atactic PS, 2708, copyright 1991, with permission from Elsevier Science)...

Figure 4.20 The spectrum estimated using the equation I = 0.60(comp.2 + 0.40(comp.3) is shown as curve 1 the steady-state fluorescence emission spectrum of iPS gel after annealing for 30 min at 318 K as curve 2 comp.2 and comp.3 correspond to spectra 2 and 3 in Figure 4.19.

Figure 1 Steady state fluorescence emission of LHCP-I at 293K and 77K.Excitation done at 435nm. Sample originally in 0.1-0.2 M sucrose diluted 5 fold. 293K Sample dilution done with SO.OmM Tricine, pH=7.8.

Natural nucleobases are essentially nonemissive with exceedingly low fluorescence quantum yields (f <3 x lO" ) suggesting subpicosecond excited state Ufetimes." Incorporation of nonnatural chromophores into (or on) the bases can provide information about the local environment by monitoring transient or steady-state fluorescent emission (see Luminescent Spectroscopy in Supramolecular Chemistry, Techniques). Emission intensity can increase, decrease, or shift in wavelength depending on the chro-mophore and its local enviromnent, making these fluorescent analogs tunable for specific experiments. Synthetic fluorescent bases can be utilized as probes for nucleic acid structure, dynamics, and interactions. There is an extensive amount of structural variation in fluorescent nucleobase mimics because there is no universal chromophore that is adaptable to every biopolymeric system. 

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