Mutagenic effects on the fluorescence of tryptophan residues in bacteriophage T4 lysozyme: correlation with dynamics

Bruce S Hudson, Dan Harris

Research output: Chapter in Book/Report/Conference proceedingConference contribution

3 Scopus citations

Abstract

Site-directed mutagenesis of specific residues in bacteriophage T4 lysozyme is shown to result in changes in the emission spectra of the tryptophan residues of this protein. In some cases a significant red-shift is observed. This is interpreted in terms of enhanced dielectric relaxation due to fluctuations that expose a buried residue to the aqueous solvent. For substitutions at position 146, the spectral shift is strongly correlated with the rate of a specific proteolytic digestion of the T4 lysozyme by trypsin as determined by Signor, Dalzoppo, and Schellman. In cases where a spectral shift is observed there is also an enhancement of internal mobility of a tryptophan residue as indicated by the amplitude of a short correlation time component of the anisotropy decay. All of these spectral and enzymatic susceptibility effects are reversed by introduction of a disulfide linkage spanning the two lobes of the protein. The interpretation of these results in terms of molecular dynamics is discussed. The effect of mutational changes on the average fluorescence lifetime and quantum yield of tryptophan fluorescence is also discussed in terms of collisional quenching of tryptophan residues by neighboring groups.

Original languageEnglish (US)
Title of host publicationProceedings of SPIE - The International Society for Optical Engineering
PublisherPubl by Int Soc for Optical Engineering
Pages94-101
Number of pages8
Volume1640
ISBN (Print)0819407860
StatePublished - 1992
Externally publishedYes
EventTime-Resolved Laser Spectroscopy in Biochemistry III - Los Angeles, CA, USA
Duration: Jan 20 1992Jan 22 1992

Other

OtherTime-Resolved Laser Spectroscopy in Biochemistry III
CityLos Angeles, CA, USA
Period1/20/921/22/92

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ASJC Scopus subject areas

  • Electrical and Electronic Engineering
  • Condensed Matter Physics

Cite this

Hudson, B. S., & Harris, D. (1992). Mutagenic effects on the fluorescence of tryptophan residues in bacteriophage T4 lysozyme: correlation with dynamics. In Proceedings of SPIE - The International Society for Optical Engineering (Vol. 1640, pp. 94-101). Publ by Int Soc for Optical Engineering.