Abstract

Most proteins exhibit long-lived phosphorescence with lifetimes ranging from pi-sec to sec at room temperature in the absence of oxygen. Phosphorescence emission is exquisitely sensitive to environmental changes that occur on this time scale, as can be seen by the variability in lifetimes and ability to be quenched among proteins. How phosphorescence parameters are related to protein structure, dynamics and reactivity win be analyzed in the proposed research. Specific plans are to: 1. Correlate that observation of long-lived phosphorescence from tryptophan with the structure and composition of the protein. 2. Examine what determines the reactivity of excited triplet tryptophan with molecules external to the protein. 3. Study particular proteins in detail. The photochemistry of crystallins are of interest because they provide homologous proteins for study and they are very stable with high phosphorescence yield. The phosphorescence of cytochrome oxidase provides a spectroscopic parameter with which to examine the conformational changes that substrates and products induce on this complex protein.

  Funding Agency

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM034448-08
Application #
3285472
Study Section
Molecular and Cellular Biophysics Study Section (BBCA)
Project Start
1984-12-01
Project End
1995-11-30
Budget Start
1992-12-01
Budget End
1993-11-30
Support Year
8
Fiscal Year
1993
Total Cost
Indirect Cost

  Institution

Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104

  Publications

Laberge, M; Wright, W W; Sudhakar, K et al. (1997) Conformational effects of calcium release from parvalbumin: comparison of computational simulations with spectroscopic investigations. Biochemistry 36:5363-71
Jez, J M; Vanderkooi, J M; Laties, A M (1996) Spectroscopic characterization of bendazac and benzydamine: possible photochemical modes of action. Biochem Biophys Res Commun 221:266-70
Angiolillo, P J; Vanderkooi, J M (1996) Hydrogen atoms are produced when tryptophan within a protein is irradiated with ultraviolet light. Photochem Photobiol 64:492-5
Sudhakar, K; Erecinska, M; Vanderkooi, J M (1995) Interaction of polyamines with the Ca(2+)-binding protein parvalbumin. Eur J Biochem 230:498-502
Angiolillo, P J; Vanderkooi, J M (1995) Electron paramagnetic resonance of the excited triplet state of metal-free and metal-substituted cytochrome c. Biophys J 68:2505-18
Sudhakar, K; Phillips, C M; Owen, C S et al. (1995) Dynamics of parvalbumin studied by fluorescence emission and triplet absorption spectroscopy of tryptophan. Biochemistry 34:1355-63
Sudhakar, K; Phillips, C M; Williams, S A et al. (1993) Excited states of tryptophan in cod parvalbumin. Identification of a short-lived emitting triplet state at room temperature. Biophys J 64:1503-11
Wright, W W; Owen, C S; Vanderkooi, J M (1992) Penetration of analogues of H2O and CO2 in proteins studied by room temperature phosphorescence of tryptophan. Biochemistry 31:6538-44
Dadak, V; Vanderkooi, J M; Wright, W W (1992) Electron transfer from excited tryptophan to cytochrome c: mechanism of phosphorescence quenching? Biochim Biophys Acta 1100:33-9
Papp, S; Vanderkooi, J M; Owen, C S et al. (1990) Reactions of excited triplet states of metal substituted myoglobin with dioxygen and quinone. Biophys J 58:177-86

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