Abstract
Artificial bacteriorhodopsin (bR) pigments based on synthetic retinal analogues with selectively blocked single and double bonds were prepared. It was shown that rotations around single bonds C12-C13 and C10-C11 and isomerizations of C11=C12 and C9=C10 are not required either for initiating the photocycle of all-trans-bR or for forming its M412 intermediate. The results are discussed in light of mechanisms for the primary event (based on the C13=C14 isomerization) involving a concerted double-bond and single-bond rotation around adjacent C,C bonds. Similarly, the photoreaction of the 13-cis isomer of bacteriorhodopsin does not require isomerization about the C11=C12 double bond or rotation around C12-C13. It is also shown that 13-cis ⇔ all-trans (light-dark adaptation) reaction of bacteriorhodopsin does not involve additional rotations or isomerizations involving the C9-C13 section of the molecule.
Original language | English |
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Pages (from-to) | 4614-4618 |
Number of pages | 5 |
Journal | Journal of the American Chemical Society |
Volume | 108 |
Issue number | 15 |
DOIs | |
State | Published - 1986 |
Externally published | Yes |