Photosynthetic reaction center (RC) pigment protein complex converts the free energy of light into chemical potential of charge pairs with extremely high efficiency. A transient phase in the absorption spectrum in the sub-millisecond time scale is expected to be especially important to examine the conformational gating model of the Q(A)Q(B) to Q(A)Q(B) (here Q(A )and Q(B) are the primary and secondary quinone type electron acceptors, respectively) electron transport. Essential kinetic components at few tens of microseconds scale and at around 200 microseconds have been suggested. We investigated the conformation change of RCs using heterodyne detection of the laser-induced transient grating method. An about 25 microseconds dynamics was observed, which coincides with the one described by the conformational gating model and possibly related to the nonadiabatic intrinsic Q(A)Q(B) to Q(A)Q(B) electron transport. The relative intensity of this component decreased with increasing quinone concentration indicating an initial (P+Q(A))1 or a relaxed (P+Q(A))2 conformational substate. We did not find the decay component at few hundreds of microseconds time scale indicating that there is no large displacement in the RC structure if Q(B) is present. The diffusion coefficient of the RC/LDAO detergent micelles calculated from the kinetic component was D = 3.8 x 10(-11 ) m2/s that agrees fairly well with the number estimated from the Einstein-Stokes relationship, and relates to a hydrodynamic diameter of 11.4 nm of the RC in LDAO micellar solution.
Soft ionization, high-resolution mass spectrometry is widely used to characterize large biological molecules, such as proteins. Deconvolution ('deisotoping') of isotopic envelopes (iEs) in biological mass spectra into monoisotopic or average masses is challenging due to low signals a...
We show that the difference resonance driven by the space charge
Pseudo-octupole of high-intensity beams not only couples the beam core
Emittances; it can also lead to emittance exchange in the beam halo, which is
Of relevance for beam loss in high intensity accelerators. With reference to
We perform numerical experiments to investigate the influence of inelastic
Neutrino reactions with light nuclei on the standing accretion shock
Instability. The time evolutions of shock waves are calculated with a simple
Light-bulb approximation for the neutrino transport and a multi-nuclei equation...
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