Tryptophan proteins

L. Zheng and J.D. Brennan, Measurement of intrinsic fluorescence to probe the conformational flexibility and thermodynamic stability of a single tryptophan protein entrapped in a sol-gel derived glass matrix. Analyst 123, 1735-1744 (1998). 

A. P. Demchenko, Red-edge-excitation spectroscopy of single-tryptophan proteins, Eur. Biophys. J. 16, 121-129 (1988). 

The width of the 0-0 line in single-tryptophan proteins at 77 K has been interpreted to reflect inhomogeneous broadening arising because the protein exists as a distribution of conformations. 30 34 The width of the 0-0 band of liver alcohol dehydrogenase is 500 cm-1 at 22°C.(10 31 35) The widths of the 0-0 transition for other proteins are somewhat greater. In many cases for the spectra taken at room temperature, low-resolution optics were used (as in Figure 3.2), and hence the published spectra may overestimate the width of the emission band. 

For single-tryptophan proteins there is some correlation between blue-shifted fluorescence emission maximum and phosphorescence lifetime (Table 3.2). Another correlation is that three of the proteins which exhibit phosphorescence, azurin, protease (subtilisin Carlsberg), and ribonuclease Tlt are reported to show resolved fluorescence emission at 77 K. Both blue-shifted emission spectra and resolved spectra are characteristic of indole in a hydrocarbon-like matrix. 

Table 3.2. Correlation between Fluorescence Emission Maximum and Phosphorescence Lifetime in Single-Tryptophan Proteins 1...

J. Domanus, G. B. Strambini, and W. Galley, Heterogeneity in the thermally-induced quenching of the phosphorescence of multi-tryptophan proteins, Photochem. Photobiol. 34, 15-21 (1980). 

Di Venere, A., Mei, G., Gilardi, G. el al. (1998). Resolution of the heterogeneous fluorescence in multi-tryptophan proteins ascorbate oxidase. European Journal of Biochemistry, 257, 337-343. 

Engelborghs Y. The analysis of time resolved protein fluorescence in multi-tryptophan proteins. Spectrochim. Acta, Part A 2001 57 2255-2270. 

In a multi-tryptophan protein, fluorescence quantum yield of the tryptophans can be additive or not. In the first case, the others do not influence each tryptophan while in the second case mainly energy transfer to or from the other tryptophan residues can influence quantum yield. In the absence of energy transfer between the tryptophan residues, mutants with one tryptophan residue are prepared, the other tryptophan residues of the protein are replaced by phenylalanine, and quantum yield of the corresponding tryptophan in each mutant is determined experimentally by comparing its fluorescence to that of free tryptophan in solution. For example, quantum yields of tryptophan residues in Bamase have been determined in the wild type and in mutants where only one tryptophan residue has been conserved. 

A. Monellin—A Single-Tryptophan Protein with Three Decay Times... 

The single-tryptophan protein st ylococcal nuclease is known to display a dominant single-exponendal dec as... 

The azurins also pro>tide examples of single-tryptophan proteins with the tryptO dian residues located in differem... 

B. Fractional AccessHiility to Quenching in Multi-Tryptophan Proteins... 

A. Protein Tyrosyl Phosphatase— Simple Two-Tryptophan Protein... 

Lakowicz, J. R.. Gryezynski, I., Szmacinski, H., CSierek, Hh and Joshi, N., 1991, Anisotropy decays of single tryptophan proteins measured by GHz frequency-dorasin fluorometry whh ooUisImial flenching, Eur. Biophys. J. 19 125-140. 

Sillen, A., Hennecke, J., Roethlisberger, D., Glockshuber, R., Engelborghs, Y. Fluorescence quenching in the DsbA protein from Escherichia coli complete picture of the excited-state energy pathway and evidence for the reshuffling dynamics of the microstates of tryptophan. Protein Sci. 37, 253-263 (1999)... 

B, 2 (19), 2868-2873 (e) Zheng, L. and Breiman, J.D. (1998) Measurement of intrinsic fluorescence to probe the conformational flexibility and thermodynamic stability of a single tryptophan protein entrapped in a sol-gel derived glass matrix. Analyst, 123 (8), 1735-1744 (f) Zheng, L Flora, K., and Brennan, J.D. (1998) Improving the performance of a sol-gel-entrapped metalbinding protein by maximizing protein thermal stability before entrapment Chem. Mater., 10 (12), 3974-3983 (g)... 

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