Two excited states in aequorin bioluminescence induced by tryptophan modification.
The Ca(2+)-activated photoprotein, aequorin, contains six tryptophan residues and has a bioluminescence emission maximum at 465 nm. On converting the six tryptophan residues to phenylalanine, the mutant aequorins exhibited varied luminescence activities and spectra, but one mutant, with tryptophan-86 replaced by phenylalanine, gave a bimodal emission spectrum, with maxima at 455 nm and 400 nm. This result suggests that tryptophan-86 may be importantly involved in the generation of the product excited state during aequorin bioluminescence.
Ohmiya
Y
Y
Osaka Bioscience Institute, Japan.
Ohashi
M
M
Tsuji
F I
FI
D000331:Aequorin / Q000737:chemistry* / Q000235:genetics; D002942:Circular Dichroism; D003001:Cloning, Molecular; D004926:Escherichia coli / Q000235:genetics; D049449:Luminescence; D015394:Molecular Structure; D013057:Spectrum Analysis; D014364:Tryptophan / Q000737:chemistry*
D000331:Aequorin; D014364:Tryptophan