Ultrafast intramolecular relaxation dynamics of Mg- and Zn-bacteriochlorophyll a.

Ultrafast excited-state dynamics of the photosynthetic pigment (Mg-)bacteriochlorophyll a and its Zn-substituted form were investigated by steady-state absorption∕fluorescence and femtosecond pump-probe spectroscopic measurements. The obtained steady-state absorption and fluorescence spectra of bacteriochlorophyll a in solution showed that the central metal compound significantly affects the energy of the Qx state, but has almost no effect on the Qy state. Photo-induced absorption spectra were recorded upon excitation of Mg- and Zn-bacteriochlorophyll a into either their Qx or Qy state.

Ultrafast excited state dynamics of spirilloxanthin in solution and bound to core antenna complexes: identification of the S∗ and T1 states.

Ultrafast excited state dynamics of spirilloxanthin in solution and bound to the light-harvesting core antenna complexes from Rhodospirillum rubrum S1 were investigated by means of femtosecond pump-probe spectroscopic measurements. The previously proposed S∗ state of spirilloxanthin was clearly observed both in solution and bound to the light-harvesting core antenna complexes, while the lowest triplet excited state appeared only with spirilloxanthin bound to the protein complexes. Ultrafast formation of triplet spirilloxanthin bound to the protein complexes was observed upon excitation of either spirilloxanthin or bacteriochlorophyll-a.

Two critical residues in p-loop regions of puffer fish Na+ channels on TTX sensitivity.

We previously showed that Asn-383 and Thr-1569 residues of p-loop regions in domains I and IV, respectively, of the puffer fish, Fugu pardialis, skeletal muscle Na(v) (fNa(v)1.4a), are anomalous to those of other species of TTX-sensitive Na(+) channels, where the aromatic residues of Phe or Tyr, and Gly are the counterparts [Yotsu-Yamashita, M., Nishimori, K.