Analogue chromophore study of the influence of electronic perturbation on color regulation of photoactive yellow protein.
We report a unique lambdamax shift of the absorption maximum of a photoactive yellow protein (PYP) analogue reconstituted with a fluorinated chromophore (F-PYP). The difference in lambdamax between the free chromophore and the protein was significantly larger than that with the native chromophore. We concluded that the unusual lambdamax shift is caused by the electronegative character of the fluorine atom and not by steric hindrance. This result suggests that formation of a hydrogen bond between the fluorine atom and one or more amino acid residues could neutralize its electron-withdrawing character. The properties of analogues of PYP with brominated and methylated chromophore could be explained as an effect of steric hindrance.
Yamada
Hiroshi
H
Department of Earth and Space Science, Graduate School of Science, Osaka University, Toyonaka, Osaka 560-0043, Japan.
Kumauchi
Masato
M
Hamada
Norio
N
Zheng
Xiang-Guo
XG
Park
Il Ho
IH
Masuda
Katsuyoshi
K
Yoshihara
Kazuo
K
Tokunaga
Fumio
F
D001426:Bacterial Proteins / Q000737:chemistry*; D003116:Color; D004563:Electrochemistry; D006863:Hydrogen-Ion Concentration; D020283:Photoreceptors, Microbial / Q000737:chemistry*; D013053:Spectrophotometry; D013056:Spectrophotometry, Ultraviolet
D001426:Bacterial Proteins; D020283:Photoreceptors, Microbial; C050162:photoactive yellow protein, Bacteria