Determination of the rate and yield of B-side quinone reduction in Rhodobacter capsulatus reaction centers.


:In the native purple bacterial reaction center (RC), light-driven charge separation utilizes only the A-side cofactors, with the symmetry related B-side inactive. The process is initiated by electron transfer from the excited primary donor (P*) to the A-side bacteriopheophytin (P* --> P+ H(A)-) in approximately 3 ps. This is followed by electron transfer to the A-side quinone (P+ H(A)- --> P+ Q(A)-) in approximately 200 ps, with an overall quantum yield of approximately 100%. Using nanosecond flash photolysis and RCs from the Rhodobacter capsulatus F(L181)Y/Y(M208)F/L(M212)H mutant (designated YFH), we have probed the decay pathways of the analogous B-side state P+ H(B)-. The rate of the P+ H(B)- --> ground-state charge-recombination process is found to be (3.0 +/- 0.8 ns)(-1), which is much faster than the analogous (10-20 ns)(-1) rate of P+ H(A)- --> ground state. The rate of P+ H(B)- --> P+ Q(B)- electron transfer is determined to be (3.9 +/- 0.9 ns)(-1), which is about a factor of 20 slower than the analogous A-side process P+ H(A)- --> P+ Q(A)-. The yield of P+ H(B)- --> P+ Q(B)- electron-transfer calculated from these rate constants is 44%. This value, when combined with the known 30% yield of P+ H(B)- from P in YFH RCs, gives an overall yield of 13% for B-side charge separation P* --> P+ H(B)- --> P+ Q(B)- in this mutant. We determine essentially the same value (15%) by comparing the P-bleaching amplitude at approximately 1 ms in YFH and wild-type RCs.






Kee HL,Laible PD,Bautista JA,Hanson DK,Holten D,Kirmaier C




Has Abstract


2006-06-13 00:00:00












  • Electronic spectroscopy of cobalt angiotensin converting enzyme and its inhibitor complexes.

    abstract::Zinc, the catalytically essential metal of angiotensin converting enzyme (ACE), has been replaced by cobalt(II) to give an active, chromophoric enzyme that is spectroscopically responsive to inhibitor binding. Visible absorption spectroscopy and magnetic circular dichroic spectropolarimetry have been used to character...


    pub_type: 杂志文章


    authors: Bicknell R,Holmquist B,Lee FS,Martin MT,Riordan JF

    更新日期:1987-11-17 00:00:00

  • Peptide cross-linking to calmodulin: attachment of [Tyr8]substance P.

    abstract::Ultraviolet irradiation of calmodulin in the presence of calcium results in either the intramolecular cross-linking of Tyr99 and Tyr138 [Malencik, D.A., & Anderson, S.R. (1986) Biochemistry 25, 709] or, when [Tyr8]substance P is bound, the generation of peptide-calmodulin adducts. The latter consist of two chromatogra...


    pub_type: 杂志文章


    authors: Malencik DA,Anderson SR

    更新日期:1988-02-09 00:00:00

  • Structural and catalytic properties of hydrogenase from Chromatium.

    abstract::The enzyme hydrogenase, from the photosynthetic bacterium Chromatium, was purified to homogeneity after solubilization of the particulate enzyme with deoxycholate. The purification procedure included ammonium sulfate fractionation, treatment with manganous phosphate gel, heating at 63 degrees, DEAE-cellulose chromatog...


    pub_type: 杂志文章


    authors: Gitlitz PH,Krasna AI

    更新日期:1975-06-17 00:00:00

  • Specificity determinants on Cdc42 for binding its effector protein ACK.

    abstract::Cdc42 and Rac are highly homologous members of the Rho family of small G proteins that interact with several downstream effector proteins thereby causing cytoskeletal rearrangements, cell proliferation, and differentiation. While some effectors, such as the tyrosine kinase, ACK, and the scaffold protein, WASP, are uni...


    pub_type: 杂志文章


    authors: Elliot-Smith AE,Mott HR,Lowe PN,Laue ED,Owen D

    更新日期:2005-09-20 00:00:00

  • Kinetic and spectroscopic properties of the YZ* radical in Ca2+- and Cl--depleted photosystem II preparations.

    abstract::Depletion of Ca2+ and/or Cl- ions from PSII membranes blocks the electron-transfer reactions that precede O2 evolution on the oxidizing side of the enzyme. Illumination of these inhibited preparations at 273 K generates a paramagnetic species that is detectable by low-temperature (T < 20 K) EPR as a signal in the g = ...


    pub_type: 杂志文章


    authors: Lydakis-Simantiris N,Dorlet P,Ghanotakis DF,Babcock GT

    更新日期:1998-05-05 00:00:00

  • Subsite interactions of ribonuclease T1: viscosity effects indicate that the rate-limiting step of GpN transesterification depends on the nature of N.

    abstract::We report on the effect of the viscogenic agents glycerol and ficoll on the RNase T1 catalyzed turnover of GpA, GpC, GpU, and Torula yeast RNA. For wild-type enzyme, we find that the kcat/Km values for the transesterification of GpC and GpA as well as for the cleavage of RNA are inversely proportional to the relative ...


    pub_type: 杂志文章


    authors: Steyaert J,Wyns L,Stanssens P

    更新日期:1991-09-03 00:00:00

  • Coordinated chromatin control: structural and functional linkage of DNA and histone methylation.

    abstract::One of the most fundamental questions in the control of gene expression in mammals is how epigenetic methylation patterns of DNA and histones are established, erased, and recognized. This central process in controlling metazoan gene expression includes coordinated covalent modifications of DNA and its associated histo...


    pub_type: 杂志文章,评审


    authors: Cheng X,Blumenthal RM

    更新日期:2010-04-13 00:00:00

  • Inhibition of mouse erythroid band 3-mediated chloride transport by site-directed mutagenesis of histidine residues and its reversal by second site mutation of Lys 558, the locus of covalent H2DIDS binding.

    abstract::Substitution by site-directed mutagenesis of any one of the histidine residues H721, H837, and H852 by glutamine, or of H752 by serine, inhibits Cl- flux mediated by band 3 expressed in Xenopus oocytes. Mutation of Lys 558 (K558N), the site of covalent binding of H2DIDS (4,4'-diisothiocyanostilbene-2,2'-disulfonate) i...


    pub_type: 杂志文章


    authors: Müller-Berger S,Karbach D,König J,Lepke S,Wood PG,Appelhans H,Passow H

    更新日期:1995-07-25 00:00:00

  • Levuglandin forms adducts with histone h4 in a cyclooxygenase-2-dependent manner, altering its interaction with DNA.

    abstract::Inflammation and subsequent cyclooxygenase-2 (COX-2) activity has long been linked with the development of cancer, although little is known about any epigenetic effects of COX-2. A product of COX-2 activation, levuglandin (LG) quickly forms covalent bonds with nearby primary amines, such as those in lysine, which lead...


    pub_type: 杂志文章


    authors: Carrier EJ,Zagol-Ikapitte I,Amarnath V,Boutaud O,Oates JA

    更新日期:2014-04-22 00:00:00

  • Residues 207, 216, and 221 and the catalytic activity of mGSTA1-1 and mGSTA2-2 toward benzo[a]pyrene-(7R,8S)-diol-(9S,10R)-epoxide.

    abstract::Murine class alpha glutathione S-transferase subunit types A2 (mGSTA2-2) and A1 (mGSTA1-1) have high catalytic efficiency for glutathione (GSH) conjugation of the ultimate carcinogenic metabolite of benzo[a]pyrene, (+)-anti-7,8-dihydroxy-9,10-oxy-7,8,9,10-tetrahydrobenzo[a]pyrene, [(+)-anti-BPDE]. Only 10 residues dif...


    pub_type: 杂志文章


    authors: Gu Y,Xiao B,Wargo HL,Bucher MH,Singh SV,Ji X

    更新日期:2003-02-04 00:00:00

  • Relationship between folding and function in a sequence-specific miniature DNA-binding protein.

    abstract::Previously, we have described a miniature protein-based approach to the design of molecules that bind DNA or protein surfaces with high affinity and specificity. In this approach, the small, well-folded protein avian pancreatic polypeptide acts as a scaffold to present and stabilize an alpha-helical or PPII-helical re...


    pub_type: 杂志文章


    authors: Yang L,Schepartz A

    更新日期:2005-05-24 00:00:00

  • Absence of evidence for metabolite-modulated association between alpha-glycerol-3-phosphate dehydrogenase and L-lactate dehydrogenase.

    abstract::Evidence for the NADH-modulated formation of a complex between alpha-glycerol-3-phosphate dehydrogenase and l-lactate dehydrogenase was reported [Yong, H., Thomas, G. A., and Peticolas, W. L. (1993) Biochemistry 32, 11124-11131]. This NADH-modulated association suggested a mechanism of potentially great importance to ...


    pub_type: 杂志文章


    authors: Lehoux EA,Baker SM,Kovina MV,Hays FA,Spivey HO

    更新日期:2003-05-27 00:00:00

  • Effects of DNA binding proteins on DNA methylation in vitro.

    abstract::The inheritance of DNA methylation patterns may play an important role in the stability of the differentiated state. We have therefore studied the inhibitory effects of DNA binding proteins on DNA methylation in vitro. Mouse L1210 cells grown in the presence of 5-azacytidine acquire hemimethylated sites in their DNA. ...


    pub_type: 杂志文章


    authors: Kautiainen TL,Jones PA

    更新日期:1985-02-26 00:00:00

  • Kinetics of oxidative phosphorylation in Paracoccus denitrificans. 1. Mechanism of ATP synthesis at the active site(s) of F0F1-ATPase.

    abstract::(1) The rate of ATP synthesis during NADH-driven aerobic respiration has been measured in plasma membrane vesicles from Paracoccus denitrificans as a function of the concentration of the substrates, ADP and inorganic phosphate (Pi). In both cases, the response of the reaction to changes in the degree of saturation of ...


    pub_type: 杂志文章


    authors: Pérez JA,Ferguson SJ

    更新日期:1990-11-20 00:00:00

  • Inhibition of protein interactions with the beta 2 sliding clamp of Escherichia coli DNA polymerase III by peptides from beta 2-binding proteins.

    abstract::The sliding clamp of the Escherichia coli replisome is now understood to interact with many proteins involved in DNA synthesis and repair. A universal interaction motif is proposed to be one mechanism by which those proteins bind the E. coli sliding clamp, a homodimer of the beta subunit, at a single site on the dimer...


    pub_type: 杂志文章


    authors: Wijffels G,Dalrymple BP,Prosselkov P,Kongsuwan K,Epa VC,Lilley PE,Jergic S,Buchardt J,Brown SE,Alewood PF,Jennings PA,Dixon NE

    更新日期:2004-05-18 00:00:00

  • The structures of the C185S and C185A mutants of sulfite oxidase reveal rearrangement of the active site.

    abstract::Sulfite oxidase (SO) catalyzes the physiologically critical conversion of sulfite to sulfate. Enzymatic activity is dependent on the presence of the metal molybdenum complexed with a pyranopterin-dithiolene cofactor termed molybdopterin. Comparison of the amino acid sequences of SOs from a variety of sources has ident...


    pub_type: 杂志文章


    authors: Qiu JA,Wilson HL,Pushie MJ,Kisker C,George GN,Rajagopalan KV

    更新日期:2010-05-11 00:00:00

  • Differences in secondary structure between packaged and unpackaged single-stranded DNA of bacteriophage phi X174 determined by Raman spectroscopy: a model for phi X174 DNA packaging.

    abstract::The single-stranded packaged genome (ssDNA) of bacteriophage phi X174 is shown by Raman spectroscopy to lack both the ordered phosphodiester backbone and base stacking, which are demonstrated for unpackaged, protein-free ssDNA. In solutions of moderate ionic strength, unpackaged ssDNA contains 36 +/- 7% of deoxyribosy...


    pub_type: 杂志文章


    authors: Benevides JM,Stow PL,Ilag LL,Incardona NL,Thomas GJ Jr

    更新日期:1991-05-21 00:00:00

  • Parameters affecting the elongation block by RNA polymerase II at the SV40 attenuator 1 in vitro.

    abstract::We have previously suggested that folding of the SV40 attenuator RNA 1 into two hairpin elements leads to a block of transcription elongation. Using site-directed mutagenesis, we created three templates that either strengthened or weakened the proposed hairpin structures. The mutated and wild-type templates were clone...


    pub_type: 杂志文章


    authors: Goldring NB,Kessler M,Aloni Y

    更新日期:1992-09-08 00:00:00

  • Threonine inhibition of the aspartokinase--homoserine dehydrogenase I of Escherichia coli. Threonine binding studies.

    abstract::Both activities of the aspartokinase--homoserine I (AK-HSD) of Escherichia coli are inhibited by threonine. Careful threonine binding studies have now been done which have allowed us to distinguish the various effects of threonine on the enzyme. The ultrafiltration technique of H. Paulus ((1969) Anal. Biochem. 32, 101...


    pub_type: 杂志文章


    authors: Bearer CF,Neet KE

    更新日期:1978-08-22 00:00:00

  • Polymer models of protein stability, folding, and interactions.

    abstract::The unfolded state and flexible linkers in the folded structure play essential roles in protein stability and folding and protein-protein interactions. Intrinsic to these roles is the fact that unfolded proteins and flexible linkers sample many different conformations. Polymer models may capture this and complement ex...


    pub_type: 杂志文章


    authors: Zhou HX

    更新日期:2004-03-02 00:00:00

  • Structures of gangliosides from bovine adrenal medulla.

    abstract::Five gangliosides, accounting for over 95% of the total ganglioside fraction, were isolated from bovine adrenal medulla by preparative thin-layer chromatography and the carbohydrate structures determined by a combination of periodate oxidation and permethylation techniques. Partially methylated alditol acetates were g...


    pub_type: 杂志文章


    authors: Price H,Kundu S,Ledeen R

    更新日期:1975-04-08 00:00:00

  • Elucidation of the chemical nature of the steady-state intermediates in the mechanism of carboxypeptidase A.

    abstract::Cryospectrokinetic studies of zinc and cobalt carboxypeptidase A disclosed two intermediates in the hydrolysis of both peptides and depsipeptides and furnished all the rate and equilibrium constants for the reaction scheme E + S in equilibrium ES1 in equilibrium ES2---E + P [Auld, D. S., Galdes, A., Geoghegan, K. F., ...


    pub_type: 杂志文章


    authors: Galdes A,Auld DS,Vallee BL

    更新日期:1986-02-11 00:00:00

  • A probe for the mutagenic activity of the carcinogen 4-aminobiphenyl: synthesis and characterization of an M13mp10 genome containing the major carcinogen-DNA adduct at a unique site.

    abstract::The duplex genome of Escherichia coli virus M13mp10 was modified at a unique site to contain N-(deoxyguanosin-8-yl)-4-aminobiphenyl (dG8-ABP), the major carcinogen-DNA adduct of the human bladder carcinogen 4-aminobiphenyl. A tetradeoxynucleotide containing a single dG8-ABP residue was synthesized by reacting 5'-d(TpG...


    pub_type: 杂志文章


    authors: Lasko DD,Basu AK,Kadlubar FF,Evans FE,Lay JO Jr,Essigmann JM

    更新日期:1987-06-02 00:00:00

  • Temperature-dependent CD and NMR studies on a synthetic oligonucleotide containing a B-Z junction at high salt.

    abstract::It is now accepted that two or more conformations may exist within the same DNA molecule, thereby generating conformational junctions. The presence of B-Z junctions between right- and left-handed DNA conformations has been detected in plasmids by a number of techniques. Preliminary characterization of the first exampl...


    pub_type: 杂志文章


    authors: Sheardy RD,Winkle SA

    更新日期:1989-01-24 00:00:00

  • Thrombospondin-1 and angiotensin II inhibit soluble guanylyl cyclase through an increase in intracellular calcium concentration.

    abstract::Nitric oxide (NO) regulates cardiovascular hemostasis by binding to soluble guanylyl cyclase (sGC), leading to cGMP production, reduced cytosolic calcium concentration ([Ca(2+)](i)), and vasorelaxation. Thrombospondin-1 (TSP-1), a secreted matricellular protein, was recently discovered to inhibit NO signaling and sGC ...


    pub_type: 杂志文章


    authors: Ramanathan S,Mazzalupo S,Boitano S,Montfort WR

    更新日期:2011-09-13 00:00:00

  • Metal ion and substrate binding to bovine galactosyltransferase.

    abstract::Bovine milk galactosyltransferase was examined by ESR and NMR proton relaxation measurements to determine the stoichiometry and nature of manganese and UDP-Gal substrate binding. The ESR and NMR data clearly showed the binding of two (Mn(II) per mol of enzyme in the ternary complex (enzyme-manganese-UDP-Gal). The affi...


    pub_type: 杂志文章


    authors: Andree PJ,Berliner LJ

    更新日期:1980-03-04 00:00:00

  • Full-length human glutaminase in complex with an allosteric inhibitor.

    abstract::Glutaminase (GLS1/2) catalyzes the conversion of L-glutamine to L-glutamate and ammonia. The level of a splice variant of GLS1 (GAC) is elevated in certain cancers, and GAC is specifically inhibited by bis-2-(5-phenylacetimido-1,2,4,thiadiazol-2-yl)ethyl sulfide (BPTES). We report here the first full-length crystal st...


    pub_type: 杂志文章


    authors: DeLaBarre B,Gross S,Fang C,Gao Y,Jha A,Jiang F,Song J J,Wei W,Hurov JB

    更新日期:2011-12-20 00:00:00

  • Structural basis for the metal-selective activation of the manganese transport regulator of Bacillus subtilis.

    abstract::The manganese transport regulator (MntR) of Bacillus subtilis is activated by Mn(2+) to repress transcription of genes encoding transporters involved in the uptake of manganese. MntR is also strongly activated by cadmium, both in vivo and in vitro, but it is poorly activated by other metal cations, including calcium a...


    pub_type: 杂志文章


    authors: Kliegman JI,Griner SL,Helmann JD,Brennan RG,Glasfeld A

    更新日期:2006-03-21 00:00:00

  • Characterization of alanine-rich peptides, Ac-(AAKAA)n-GY-NH2 (n = 1-4), using vibrational circular dichroism and Fourier transform infrared. Conformational determination and thermal unfolding.

    abstract::Vibrational circular dichroism (VCD) and Fourier transform IR (FTIR) were measured for a series of short alanine-based peptides having the general formula Ac-(AAKAA)n-GY-NH2 (n = 1-4) from 5 to 50 degrees C in D2O and at room temperature in both TFE and H2O. In both of these latter solvents, the dominant structural fo...


    pub_type: 杂志文章


    authors: Yoder G,Pancoska P,Keiderling TA

    更新日期:1997-12-09 00:00:00

  • Slow rate of phosphodiester bond formation accounts for the strong bias that Taq DNA polymerase shows against 2',3'-dideoxynucleotide terminators.

    abstract::Taq and T7 DNA polymerases have become basic molecular biology "tools" for DNA sequence analysis. However, Taq, unlike T7 DNA polymerase, is strongly biased against the incorporation of 2',3'-dideoxynucleotide triphosphates (ddNTPs) indicating very different substrate selectivities. Equilibrium binding and rate consta...


    pub_type: 杂志文章


    authors: Brandis JW,Edwards SG,Johnson KA

    更新日期:1996-02-20 00:00:00