Abstract:
:The kinetics of charge recombination following photoexcitation by a laser pulse have been analyzed in the reaction center-light harvesting complex 1 (RC-LH1) purified from the photosynthetic bacterium Rhodobacter sphaeroides. In RC-LH1 core complexes isolated from photosynthetically grown cells P(+)Q(B)(-) recombines with an average rate constant, k approximately 0.3 s(-1), more than three times smaller than that measured in RC deprived of the LH1 (k approximately 1 s(-1)). A comparable, slowed recombination kinetics is observed in RC-LH1 complexes purified from a pufX-deleted strain. Slowing of the charge recombination kinetics is even more pronounced in RC-LH1 complexes isolated from wild-type semiaerobically grown cells (k approximately 0.2 s(-1)). Since the kinetics of P(+)Q(A)(-) recombination is unaffected by the presence of the antenna, the P(+)Q(B)(-) state appears to be energetically stabilized in core complexes. Determinations of the ubiquinone-10 (UQ(10)) complement associated with the purified RC-LH1 complexes always yield UQ(10)/RC ratios larger than 10. These quinone molecules are functionally coupled to the RC-LH1 complex, as judged from the extent of exogenous cytochrome c(2) rapidly oxidized under continuous light excitation. Analysis of P(+)Q(B)(-) recombination, based on a kinetic model which considers fast quinone equilibrium at the Q(B) binding site, indicates that the slowing down of charge recombination kinetics observed in RC-LH1 complexes cannot be explained solely by a quinone concentration effect and suggests that stabilization of the light-induced charge separation is predominantly due to interaction of the Q(B) site with the LH1 complex. The high UQ(10) complements detected in RC-LH1 core complexes, but not in purified light-harvesting complex 2 and in RC, are proposed to reflect an in vivo heterogeneity in the distribution of the quinone pool within the chromatophore bilayer.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Francia F,Dezi M,Rebecchi A,Mallardi A,Palazzo G,Melandri BA,Venturoli Gdoi
10.1021/bi048629ssubject
Has Abstractpub_date
2004-11-09 00:00:00pages
14199-210issue
44eissn
0006-2960issn
1520-4995journal_volume
43pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The physicochemical and catalytic properties of thioredoxin-T' are described. This complemented protein structure consists of a 1:1 complex between the inactive fragments thioredoxin-T-(1--73) and thioredoxin T-(74--108). These are generated by selective trypsin cleavage at Arg-73 in lysine-modified and denatured Esch...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00592a010
更新日期:1979-12-11 00:00:00
abstract::The respiratory chain complexes can arrange into multienzyme assemblies, so-called supercomplexes. We present the first 3D map of a respiratory chain supercomplex. It was determined by random conical tilt electron microscopy analysis of a bovine supercomplex consisting of complex I, dimeric complex III, and complex IV...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700983h
更新日期:2007-11-06 00:00:00
abstract::We have used 2D 1H NMR to determine the structure of glucagon-like peptide-1-(7-36) amide bound to a dodecylphosphocholine micelle. In this membranelike environment, the peptide hormone is shown to have a structure similar to that observed for glucagon. It consists of an N-terminal random coil segment (residues 1-7), ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00178a009
更新日期:1994-03-29 00:00:00
abstract::Novel inhibitors of lupin diadenosine 5',5'''-P(1),P(4)-tetraphosphate (Ap(4)A) hydrolase have been identified by in silico screening of a large virtual chemical library. Compounds were ranked on the basis of a consensus from six scoring functions. From the top 100 ranked compounds six were selected and initially scre...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900813x
更新日期:2009-08-18 00:00:00
abstract::The ferritin IRE, a highly conserved (96-99% in vertebrates) mRNA translation regulatory element in animal mRNA, was studied by molecular modeling (using MC-SYM and DOCKING) and by NMR spectroscopy. Cobalt(III) hexammine was used to model hydrated Mg2+. IRE isoforms in other mRNAs regulate mRNA translation or stabilit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9719814
更新日期:1998-02-10 00:00:00
abstract::Quorum sensing, the ability of bacteria to sense their own population density through the synthesis and detection of small molecule signals, has received a great deal of attention in recent years. Acyl homoserine lactones (AHLs) are a major class of quorum sensing signaling molecules. In nature, some bacteria that do ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi701945j
更新日期:2007-12-18 00:00:00
abstract::A recirculating Langendorff heart preparation is used to characterize the endogenous antithrombin associated reversibly with murine vascular endothelium. Rat hearts are perfused clear of blood and then recirculated with a physiological salt solution. Addition of heparin educes antithrombin activity continuously into t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00169a024
更新日期:1994-01-25 00:00:00
abstract::In fosfomycin biosynthesis, the hydrolysis of cytidylyl ( S)-2-hydroxypropylphosphonate [( S)-HPP-CMP] to afford ( S)-HPP is the only uncharacterized step. Because FomD is an uncharacterized protein with a DUF402 domain that is encoded in the fosfomycin biosynthetic gene cluster, FomD was hypothesized to be responsibl...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00690
更新日期:2018-08-14 00:00:00
abstract::5,6-Dihydrothymidine 5'-triphosphate (DHdTTP) was synthesized by catalytic hydrogenation of thymidine 5'-triphosphate (dTTP). Thymidine glycol 5'-triphosphate (dTTP-GLY) was prepared by bromination of dTTP followed by treatment with Ag2O. The modified nucleotides were extensively purified by anion-exchange high-perfor...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00377a042
更新日期:1987-02-10 00:00:00
abstract::ABCG2 is a half-ATP binding cassette (ABC) drug transporter that consists of a nucleotide binding domain (NBD) followed by a transmembrane domain. This half-ABC transporter is thought to form a homodimer in the plasma membrane where it transports anticancer drugs across the biological membranes in an ATP-dependent man...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi900675v
更新日期:2009-09-29 00:00:00
abstract::In bee venom phospholipase A2, histidine-34 probably functions as a Brønsted base to deprotonate the attacking water. Aspartate-64 and tyrosine-87 form a hydrogen bonding network with histidine-34. We have prepared mutants at these positions and studied their kinetic properties. The mutant in which histidine-34 is cha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9528412
更新日期:1996-04-09 00:00:00
abstract::Horseradish peroxidase (HRP) was oxidized by IrCl6(2-) to a mixture of compounds I and II, the rate of oxidation and the ratio of the mixture being greatly affected by pH (Hayashi & Yamazaki, 1979). Oxidation of HRP by IrCl6(2-) in the presence of fluoride was significantly accelerated. This resulted in the formation ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00046a003
更新日期:1995-11-21 00:00:00
abstract::The general view on Rhizobium chitolipooligosaccharides (CLOS) is that they are made in very low levels as diffusible molecules and are primarily secreted by the bacteria into the extracellular milieu where they interact with the host. However, the structural and predicted physicochemical properties of these amphiphil...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00011a041
更新日期:1995-03-21 00:00:00
abstract::The presence and subcellular localization of UDP-Gal:glucosylceramide beta 1----4galactosyltransferase (GalT-2) was investigated in rat liver. For this purpose, purified Golgi apparatus, endoplasmic reticulum, and plasma membrane fractions were prepared from the liver and used as the enzyme source for detecting GalT-2...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00224a021
更新日期:1991-03-12 00:00:00
abstract::A full-length cDNA encoding a calcium-dependent protein kinase with a calmodulin-like domain from Arabidopsis thaliana (AK-1 for Arabidopsis kinase-1) has been expressed as a fusion protein (called AK-1-6H) in Escherichia coli and purified to near homogeneity with high specific activity (typically 2000 nmol min-1 mg-1...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00174a008
更新日期:1994-03-01 00:00:00
abstract::LTbetaR is a member of the TNF receptor family of proteins. It binds to two different cell surface ligands, LIGHT, a homotypic trimer, and LTalpha1beta2, a heterotypic trimer. We have measured the affinities of the dimeric IgG fusion protein, LTbetaRIgG, and monomeric LTbetaR protein binding to both LIGHT and LTalpha1...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060210+
更新日期:2006-08-22 00:00:00
abstract::Our laboratory has been studying the transcriptional regulation of the nuclear gene (ATPA) that encodes the alpha-subunit of the mammalian mitochondrial F1F0 ATP synthase complex. We have previously determined that the regulatory factor, upstream stimulatory factor 2 (USF2), can stimulate transcription of the ATPA gen...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0268347
更新日期:2003-03-11 00:00:00
abstract::Cytochrome P450 158A2 (CYP158A2) has been shown to catalyze an unusual oxidative C-C coupling reaction to polymerize flaviolin and form highly conjugated pigments (three isomers of biflaviolin and one triflaviolin) in Streptomyces coelicolor A3(2) which protect the soil bacterium from deleterious effects of UV irradia...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7006959
更新日期:2007-07-31 00:00:00
abstract::Resonances of the histidine region of human carbonic anhydrase B have been studied by proton magnetic resonance spectroscopy in the presence of seven sulfonamide inhibitors. Results of difference spectroscopy and observation of the C-2 resonance of an additional titratable histidine in some of these spectra suggest a ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00675a007
更新日期:1975-02-25 00:00:00
abstract::The kinetics and energetics of the binding between barley alpha-amylase/subtilisin inhibitor (BASI) or BASI mutants and barley alpha-amylase 2 (AMY2) were determined using surface plasmon resonance and isothermal titration calorimetry (ITC). Binding kinetics were in accordance with a 1:1 binding model. At pH 5.5, [Ca(...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi020508+
更新日期:2003-02-18 00:00:00
abstract::Kinetic and structural changes in recombinant human aldose reductase (AR) due to modification by S-nitrosoglutathione (GSNO) were investigated. Incubation of the enzyme with 10-50 microM GSNO led to a time- and concentration-dependent inactivation of the enzyme, with a second-order rate constant of 0.087 +/- 0.009 M-1...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9714722
更新日期:1997-12-16 00:00:00
abstract::The relaxin-like factor (RLF) also named insulin-like 3 (INSL3) consists of two polypeptide chains linked by two interchain and one intrachain disulfide bond. RLF binds to its receptor (LGR8 also named RXFP2) through the B chain and initiates transmembrane communication by activating the adenylate cyclase through the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi300352x
更新日期:2012-05-22 00:00:00
abstract::Bacteriophage T7 RNA polymerase is a single-subunit enzyme which has a C-terminal amino acid sequence of Phe-Ala-Phe-Ala883 (FAFA883). Closely related hydrophobic sequences are present at the C termini of seven other single-subunit RNA polymerases, including the mitochondrial RNA polymerase. Mutations at any of the fo...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi962397i
更新日期:1997-03-11 00:00:00
abstract::2-Cys peroxiredoxins (Prxs) are a large and diverse family of peroxidases which, in addition to their antioxidant functions, regulate cell signaling pathways, apoptosis, and differentiation. These enzymes are obligate homodimers (alpha(2)), utilizing a unique intermolecular redox-active disulfide center for the reduct...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi012173m
更新日期:2002-04-30 00:00:00
abstract::Terpene synthases are potentially useful biocatalysts for the synthesis of valuable compounds, such as anticancer drugs and antibiotics. The design of altered activities requires better knowledge of their mechanisms, for example, an understanding of the complex conformational changes that are part of their catalytic c...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400898k
更新日期:2013-11-12 00:00:00
abstract::A 16-mer deoxyribonucleotide was labeled at the 5'-end with x-rhodamine and at the 3'-end with fluorescein. Förster resonance energy transfer was used to determine the distribution, P(R), of donor-acceptor distances for the oligomer in three duplex structures (hybridized to complementary strands having 10, 16, and 24 ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00001a036
更新日期:1995-01-10 00:00:00
abstract::We have validated that ligand peptides designed from antigen peptides could be used for targeting specific major histocompatibility complex class I (MHC-I) molecules on the cell surface. To design the ligand peptides, we used reported antigen peptides for each MHC-I molecule with high binding affinity. From the crysta...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00735
更新日期:2020-12-15 00:00:00
abstract::Chemoenzymatic glycan remodeling by endoglycosidase-catalyzed deglycosylation and reglycosylation is emerging as an attractive approach for producing homogeneous glycoforms of antibodies, and the success of this approach depends on the discovery of efficient endoglycosidases and their glycosynthase mutants. We report ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b00719
更新日期:2018-09-04 00:00:00
abstract::The structure of PsbQ, one of the three main extrinsic proteins associated with the oxygen-evolving complex (OEC) of higher plants and green algae, is examined by Fourier transform infrared (FTIR) and circular dichroic (CD) spectroscopy and by computational structural prediction methods. This protein, together with tw...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi026575l
更新日期:2003-02-04 00:00:00
abstract::A three-component soluble methane monooxygenase (sMMO) enzyme system catalyzes the hydroxylation of methane to methanol at a carboxylate-bridged diiron center housed in the alpha-subunit of the hydroxylase (MMOH). Catalysis is facilitated by the presence of a regulatory protein (MMOB) and inhibited by MMOD, a protein ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi048140z
更新日期:2004-12-28 00:00:00