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Binding of camphor to Pseudomonas putida cytochrome P450 cam : steady‐state and picosecond time‐resolved fluorescence studies
Author(s) -
Prasad Swati,
Mazumdar Shyamalava,
Mitra Samaresh
Publication year - 2000
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(00)01745-2
Subject(s) - camphor , fluorescence , chemistry , quenching (fluorescence) , pseudomonas putida , cytochrome , photochemistry , stereochemistry , biophysics , biochemistry , biology , organic chemistry , enzyme , physics , quantum mechanics
The binding of camphor to cytochrome P450 cam has been investigated by steady‐state and time‐resolved tryptophan fluorescence spectroscopy to obtain information on the substrate access channel. The fluorescence quenching experiments show that some of the tryptophan residues undergo changes in their local environment on camphor binding. The time‐resolved fluorescence decay profile gives four lifetime components in the range from 99 ps to 4.5 ns. The shortest lifetime component assigned to W42 lies close to the proposed camphor access channel. The results show that the fluorescence of W42 is greatly affected on binding of camphor, and supports dynamic fluctuations involved in the passage of camphor through the access channel as proposed earlier on the basis of crystallographic, molecular dynamics simulation and site‐directed mutagenesis studies.