Tryptophan Emission from Trypsin and Polymer Films

Kuntz, Eloise

doi:10.1038/217845a0

Cited by 11 publications

(2 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, with these assumptions the values for ,B-B calculated from the data for RNAse and insulin (0.032 and 0.064, Tyr+Phe respectively) varied by a factor of two (11). This discrepancy between proteins is not surprising since it is known from phosphorescence studies that energy transfer among the aromatic residues depends critically on the internal environment of individual proteins (9,24,25,26). Further, we have investigated whether a constant set of values would be obtained for RNAse irradiated at different wavelengths large.…”

Section: Discussionmentioning

confidence: 99%

Photochemical Yields in Ribonuclease and Oxidized Glutathione Irradiated at Different Wavelengths in the Ultraviolet

Rathinasamy¹,

Augenstein²

1968

Biophysical Journal

View full text Add to dashboard Cite

The quantum yields for the disruption of various amino acids in glutathione and ribonuclease by 229, 254, 265, and 280 nm UV photons have been determined. The results of the measurements on the destruction of tyrosine and histidine and the loss of enzymic function in RNAse and the disruption of cystine in both compounds lead to the following conclusions: (a) The photodestruction of some and perhaps many constituent amino acid residues does not cause RNAse inactivation. (b) Contrary to the basic premise of proposals made by other authors, the photochemical yields of constituent residues in a protein are not the same as that for the same amino acids in solution alone-the difference is a function of the exciting wavelength. Further, the extent of histidine destruction varies by a large factor among three proteins. (c) Consistent with previous predictions, the present results show that photons absorbed in the aromatic residues of RNAse cause the disruption of cystines elsewhere in the enzyme. (d) Although cystine disruption appears to be the most prevalent mode of RNAse inactivation by photons of the four wavelengths studied, some of the minor mechanisms leading to loss of enzymic function may vary with the UV energy.

show abstract

Section: Discussionmentioning

confidence: 99%

Photochemical Yields in Ribonuclease and Oxidized Glutathione Irradiated at Different Wavelengths in the Ultraviolet

Rathinasamy¹,

Augenstein²

1968

Biophysical Journal

View full text Add to dashboard Cite

show abstract

“…Unlike tryptophan fluorescence decay, which is sensitive to a variety of intrinsic quenchers and other effects such as solvent relaxation, typtophan phosphorescence lifetime (in the absence of disulfide groups, the only known intrinsic quenchers (Li and Galley, 1989)) is determined primarily by local rigidity (Strambini and Gonnelli, 1985). Thus, for free indole in aqueous solution the phosphorescence lifetime, T, is 11.6 ps (Bent and Hayon, 1975;Ghiron et al, 1988), whereas if constrained in a rigid polymer such as polyvinyl alcohol T approaches the 6 s observed in frozen glasses (Kuntz, 1968). The long-lived tryptophan RTP in purified proteins is necessarily associated with those tryptophans located in exceptionally inflexible regions, and this lack of local flexibility is consistent with phosphorescence anisotropy measurements that indicate that phosphorescent tryptophans are immobilized by the protein matrix on the time scale of the decay for a variety of tryptophan-containing biomolecules (Papp and Vanderkooi, 1989).…”

Section: Introductionmentioning

confidence: 95%

Time-resolved room temperature protein phosphorescence: nonexponential decay from single emitting tryptophans

Schlyer

Schauerte

Steel

et al. 1994

Biophysical Journal

View full text Add to dashboard Cite

The single room temperature phosphorescent (RTP) residue of horse liver alcohol dehydrogenase (LADH). Trp-314, and of alkaline phosphatase (AP), Trp-109, show nonexponential phosphorescence decays when the data are collected to a high degree of precision. Using the maximum entropy method (MEM) for the analysis of these decays, it is shown that AP phosphorescence decay is dominated by a single Gaussian distribution, whereas for LADH the data reveal two amplitude packets. The lifetime-normalized width of the MEM distribution for both proteins is larger than that obtained for model monoexponential chromophores (e.g., terbium in water and pyrene in cyclohexane). Experiments show that the nonexponential decay is fundamental; i.e., an intrinsic property of the pure protein. Because phosphorescence reports on the state of the emitting chromophore, such nonexponential behavior could be caused by the presence of excited state reactions. However, it is also well known that the phosphorescence lifetime of a tryptophan residue is strongly dependent on the local flexibility around the indole moiety. Hence, the nonexponential phosphorescence decay may also be caused by the presence of at least two states of different local rigidity (in the vicinity of the phosphorescing tryptophan) corresponding to different ground state conformers. The observation that in the chemically homogeneous LADH sample the phosphorescence decay kinetics depends on the excitation wavelength further supports this latter interpretation. This dependence is caused by the wavelength-selective excitation of Trp-314 in a subensemble of LADH molecules with differing hydrophobic and rigid environments. With this interpretation, the data show that interconversion of these states occurs on a time scale long compared with the phosphorescence decay (0.1-1.0 s). Further experiments reveal that with increasing temperature the distributed phosphorescence decay rates for both AP and LADH broaden, thus indicating that either 1) the number of conformational states populated at higher temperature increases or 2) the temperature differentially affects individual conformer states. The nature of the observed heterogeneous triplet state kinetics and their relationship to aspects of protein dynamics are discussed.

show abstract

Phosphorescence Instrumentation and Techniques

Kuntz

1971

Excited States of Proteins and Nucleic Acids

View full text Add to dashboard Cite

Tryptophan Emission from Trypsin and Polymer Films

Cited by 11 publications

References 8 publications

Photochemical Yields in Ribonuclease and Oxidized Glutathione Irradiated at Different Wavelengths in the Ultraviolet

Photochemical Yields in Ribonuclease and Oxidized Glutathione Irradiated at Different Wavelengths in the Ultraviolet

Time-resolved room temperature protein phosphorescence: nonexponential decay from single emitting tryptophans

Phosphorescence Instrumentation and Techniques

Contact Info

Product

Resources

About