Tryptophan |
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| The chemical structure of Tryptophan is shown at the right. The absorption and fluorescence emission spectra are shown below. The structure, absorption, and fluorescence data were all obtained from the PhotochemCAD package by Jonathan Lindsey. This excellent program allows rapid comparison of spectra and enables one to do a variety of photochemically relevant calculations. |
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Absorption
This is a graph of the molar extinction coefficient of Tryptophan dissolved in water, 0.1 M phosphate buffer, pH 7. It was measured by R. A. Fuh on summer, 95 [H. Du, R. A. Fuh, J. Li, A. Corkan, J. S. Lindsey, "PhotochemCAD: A computer-aided design and research tool in photochemistry," Photochemistry and Photobiology, 68, 141-142, 1998]. Tryptophan has a molar extinction coefficient of 5,579 M-1cm-1 at 278 nm [G. D. Fasman, Handbook of Biochemistry and Molecular Biology, Proteins, I, 183-203, CRC Press, 3 ed., 1976]. For additional fluorescence yield data, see [E. P. Kirby and R. F. Steiner, "The influence of solvent and temperature upon the fluorescence of indole derivatives.," J. Phys. Chem., 74, 4480-4490, 1970] and see [D. F. Eaton, "Reference materials for fluorescence measurement," Pure Appl. Chem., 60, 1107-1114, 1988]. |
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Fluorescence
This is the fluorescence emission spectrum of Tryptophan dissolved in water, 0.1 M phosphate buffer, pH 7. The spectrum was taken by R. A. Fuh on summer, 95 using an excitation wavelength of 270 nm [H. Du, R. A. Fuh, J. Li, A. Corkan, J. S. Lindsey, "PhotochemCAD: A computer-aided design and research tool in photochemistry," Photochemistry and Photobiology, 68, 141-142, 1998]. The quantum yield is 0.12 [R. Chen, "Measurements of absolute values in biochemical fluorescence spectroscopy," J. Research National Bureau Standards, 76A(6), 593-606, 1972]. |
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