The fluorescence emission spectrum of Tryptophan dissolved in water, 0.1 M phosphate buffer, pH 7. The excitation wavelength was 270nm. The quantum yield of this molecule is 0.12 (Chen, 1972). This spectrum was collected by in the summer of 1995 using a Spex FluoroMax.

Aug 5, 2021 · Two separate peaks at ∼330 nm and ∼360 nm are especially prominent in the spectrum of human epidermal growth factor. In contrast, in smoothed (either mathematically, or physically) spectra of Trp-containing proteins a single maximum of fluorescence varies between 330 and 360 nm.

Tryptophan can be selectively excited at 295 nm as there is little absorption by other residues at this wavelength. Upon excitation, tryptophan gives rise to an emission spectrum that peaks at 355 nm.

Nov 3, 2006 · Through simple and inexpensive experiments the students learn how to record excitation and emission spectra and measure intrinsic protein fluorescence and its quenching to elucidate the local tryptophan environment. Free tryptophan, ovalbumin, and bovine serum albumin are used for the experiments.

Jul 15, 2009 · Here we present a review of approaches developed for the decomposition of multi-component protein tryptophan fluorescence spectra and correlation of these spectral parameters with protein structural properties.

Apr 4, 2019 · When a tryptophan is completely exposed to the polar aqueous environment, the emission maximum is around 350 nm, as found for the free amino acid in water, whereas the emission maximum can be as low as 310 nm in a very hydrophobic environment [2] (a well-known example is azurin [3]).

Tryptophan is the most widely used intrinsic probe. The absorption spectrum, centered at 280 nm, displays two overlapping absorbance transitions. In contrast, the fluorescence emission spectrum is broad and is characterized by a large Stokes shift, which varies with the polarity of …

Sep 20, 2024 · In a protein, the emission maximum of tryptophan can vary from 307 to 353 nanometers. The wavelength, maximum and intensity of emission is highly dependent on the immediate environment around the tryptophan sidechain. Buried tryptophan residues in folded proteins exhibit a spectral shift of up to 20 nm due to their hydrophobic environment.

Sep 9, 2021 · the steady-state emission spectrum gives rise to broad-band emission, which is observed as inhomogeneous broad-ening of the spectra. This broadening is then dependent on the excitation energy used, since as one decreases the exci-tation energy there is an increasing photoselection of states (Figure 1A).

Intrinsic Förster resonance energy transfer (iFRET), a recently developed technique, utilizes the intrinsic fluorescence of tryptophan in conjunction with target-specific fluorescent probes as FRET donors and acceptors, respectively, for real time detection of native proteins.