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• W2081655512 endingPage "11869" @default.
• W2081655512 startingPage "11859" @default.
• W2081655512 abstract "The photosynthetic reaction center (RC) is an integral membrane protein that carries out the initial charge-separation reactions of photosynthesis. Upon light excitation, a pair (P) of bacteriochlorophylls (Bchls) donates an electron to a bacteriopheophytin (HL), generating an ion-pair state (P+HL-). Previous ENDOR studies of RCs from the purple bacterium Rhodobacter sphaeroides have shown that the unpaired electron of P+ is distributed unequally between the two Bchls of P, with about 2/3 of the unpaired spin and positive charge residing on the Bchl bound to subunit L (PL) and 1/3 on the Bchl bound to M (PM). To investigate the protein's role in establishing the energies of the cations PL+ and PM+ through long-range electrostatic interactions, we mutated Arg L135 and Arg M164 individually to Leu or Glu and measured the effects on the Special TRIPLE and FTIR spectra of P+. These highly conserved residues occupy homologous positions on either side of P but have no hydrogen bonds or steric interactions with the pigments. Previous work has shown that replacing Arg by Leu at either site lowers the midpoint potential (Em) of P/P+ by about 15 mV; replacing it by Glu lowers the Em by about 35 mV. We found that the mutations also alter the spin distribution in P+. The mutation R(L135)E stabilizes PL+ relative to PM+, increasing the ratio of the spins to 3.1, whereas R(M164)E decreases the spin ratio to 1.3. Replacing R(L135) or R(M164) by Leu gave spin ratios of 2.9 or 1.6, respectively. FTIR measurements showed that the mutations also affect the vibrational spectra of P and P+ and the electronic transition between the eigenstates of P+. The R(L135)E mutation increases the splitting between the keto CO stretching bands of PL+ and PM+, whereas the R(M164)E mutation decreases this splitting. The changes in the keto frequency are correlated with calculated changes in the projection of the local electric field along the CO bond, and give a Stark tuning rate in the range 0.81−1.45 cm-1/(MV/cm). Cooling the RCs to 100 K during illumination increases the splitting between the keto bands of PL+ and PM+ in wild-type and R(L135)E RCs and shifts the electronic transition to higher energies, suggesting that relaxations of the protein further stabilize PL+ relative to PM+. Fitting the electrochemical, ENDOR, and FTIR data to a self-consistent molecular orbital model required including both vibronic and electronic coupling of PL+ and PM+ and yielded an electronic coupling constant of approximately −155 meV and a reorganization energy of approximately 220 meV." @default.
• W2081655512 created "2016-06-24" @default.
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• W2081655512 date "2002-10-23" @default.
• W2081655512 modified "2023-10-18" @default.
• W2081655512 title "Electronic and Vibronic Coupling of the Special Pair of Bacteriochlorophylls in Photosynthetic Reaction Centers from Wild-Type and Mutant Strains of<i>Rhodobacter S</i><i>phaeroides</i>" @default.
• W2081655512 cites W147472541 @default.
• W2081655512 cites W1544940756 @default.
• W2081655512 cites W1916260872 @default.
• W2081655512 cites W1964546211 @default.
• W2081655512 cites W1966165983 @default.
• W2081655512 cites W1968655088 @default.
• W2081655512 cites W1969828804 @default.
• W2081655512 cites W1971573931 @default.
• W2081655512 cites W1971959496 @default.
• W2081655512 cites W1973040844 @default.
• W2081655512 cites W1973282880 @default.
• W2081655512 cites W1975122499 @default.
• W2081655512 cites W1977829473 @default.
• W2081655512 cites W1985392363 @default.
• W2081655512 cites W1987016321 @default.
• W2081655512 cites W1987981402 @default.
• W2081655512 cites W1988315260 @default.
• W2081655512 cites W1988484551 @default.
• W2081655512 cites W1992306338 @default.
• W2081655512 cites W1999607918 @default.
• W2081655512 cites W1999927467 @default.
• W2081655512 cites W2001166060 @default.
• W2081655512 cites W2001218559 @default.
• W2081655512 cites W2005735546 @default.
• W2081655512 cites W2007050932 @default.
• W2081655512 cites W2008523417 @default.
• W2081655512 cites W2009379756 @default.
• W2081655512 cites W2010760500 @default.
• W2081655512 cites W2012317280 @default.
• W2081655512 cites W2012800726 @default.
• W2081655512 cites W2014397498 @default.
• W2081655512 cites W2018871420 @default.
• W2081655512 cites W2019678428 @default.
• W2081655512 cites W2020118781 @default.
• W2081655512 cites W2021343914 @default.
• W2081655512 cites W2028597160 @default.
• W2081655512 cites W2029449965 @default.
• W2081655512 cites W2034782648 @default.
• W2081655512 cites W2038030945 @default.
• W2081655512 cites W2046545457 @default.
• W2081655512 cites W2047253280 @default.
• W2081655512 cites W2047508749 @default.
• W2081655512 cites W2050259250 @default.
• W2081655512 cites W2051876844 @default.
• W2081655512 cites W2054117698 @default.
• W2081655512 cites W2055866972 @default.
• W2081655512 cites W2056150266 @default.
• W2081655512 cites W2056965536 @default.
• W2081655512 cites W2058044797 @default.
• W2081655512 cites W2062115005 @default.
• W2081655512 cites W2063780436 @default.
• W2081655512 cites W2064590904 @default.
• W2081655512 cites W2069822075 @default.
• W2081655512 cites W2071084287 @default.
• W2081655512 cites W2072450767 @default.
• W2081655512 cites W2074106683 @default.
• W2081655512 cites W2077571380 @default.
• W2081655512 cites W2079011328 @default.
• W2081655512 cites W2081609525 @default.
• W2081655512 cites W2085754750 @default.
• W2081655512 cites W2086903778 @default.
• W2081655512 cites W2090640399 @default.
• W2081655512 cites W2090952136 @default.
• W2081655512 cites W2092307738 @default.
• W2081655512 cites W2092978809 @default.
• W2081655512 cites W2093294212 @default.
• W2081655512 cites W2098500343 @default.
• W2081655512 cites W2102156562 @default.
• W2081655512 cites W2114067579 @default.
• W2081655512 cites W2116830494 @default.
• W2081655512 cites W2166305691 @default.
• W2081655512 cites W2247933943 @default.
• W2081655512 cites W288053789 @default.
• W2081655512 cites W4251950018 @default.
• W2081655512 cites W67796708 @default.
• W2081655512 doi "https://doi.org/10.1021/jp021024q" @default.
• W2081655512 hasPublicationYear "2002" @default.
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