Abstract:
:Single mutations of three amino acid residues in the vicinity of the primary electron donor, P, in the reaction center (RC) from Rhodobacter (Rb.) sphaeroides were constructed and characterized in order to study the effects of hydrogen-bonding on the physical properties of P. The mutations, Phe M197-->Tyr, Met L248-->Thr, and Ser L244-->Gly, represent single amino acid changes near P designed to introduce residues found in Rhodopseudomonas (Rps.) viridis and to, thus, probe the effects of nonconserved residues. The mutations were designed to change the nonconserved H-bonding interactions of P in Rb. sphaeroides, at the level of a C2 acetyl, a C9 keto, and a C10 ester carbonyl of P, respectively, to those present in Rps. viridis. The Fourier transform (pre)resonance Raman (FTRR) spectra of P, in its reduced and oxidized states, from reaction centers of these mutants were studied to determine modifications of H-bond interactions of the pi-conjugated C2 acetyl and C9 keto carbonyl groups and the C10 carbomethoxy ester carbonyl groups of P. The vibrational spectra of reduced P in the Met L248-->Thr and Ser L244-->Gly mutants reveal no evidence for changes in the H-bonding pattern of P; this suggests that for Rb. sphaeroides wild type, Ser L244 is not H-bonded to the C10 ester carbonyl of PL. The vibrational spectrum of reduced P from the Phe M197-->Tyr mutant compared to that of wild type can unambiguously be interpreted in terms of the formation of a new H-bond with an acetyl carbonyl of P, specifically PM. Correlating with the new H-bond, the Phe M197-->Tyr mutant exhibits an electronic absorption spectrum where the P absorption band is significantly perturbed. Intact cell and chromatophore photobleaching spectra of the same mutant indicate that the P absorption band has red-shifted by ca. 10 nm; no such behavior is observed for the other mutants. As well, the P-->BPheL electron transfer rate does not seem to strongly depend on the H-bonding of the C2 acetyl carbonyl of PM to a tyrosine residue. The EPR zero-field splitting parameters, E and D, of the primary donor triplet are only slightly modified in the mutant reaction centers, on the order of 1%.(ABSTRACT TRUNCATED AT 400 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Wachtveitl J,Farchaus JW,Das R,Lutz M,Robert B,Mattioli TAdoi
10.1021/bi00210a041subject
Has Abstractpub_date
1993-11-30 00:00:00pages
12875-86issue
47eissn
0006-2960issn
1520-4995journal_volume
32pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Factor X (FX) is one of the major players in the blood coagulation cascade. Upon activation to FXa, it converts prothrombin to thrombin, which in turn converts fibrinogen into fibrin (blood clots). FXa deficiency causes hemostasis defects, such as intracranial bleeding, hemathrosis, and gastrointestinal blood loss. He...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500770p
更新日期:2014-11-11 00:00:00
abstract::Molecular dynamics simulations have been used to successfully reproduce the observed pH-dependent conformational properties of the amyloid beta(1-28) peptide [Kirshenbaum and Daggett (1995) Biochemistry, 34, 7629-7639]. On the basis of these simulations a mechanism was proposed for the unfolding of the N-terminal port...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00023a010
更新日期:1995-06-13 00:00:00
abstract::Several recent studies have provided evidence that LIN28, a cytoplasmic RNA-binding protein, inhibits the biogenesis of members of the let-7 microRNA family at the Dicer step in both mammals and Caenorhabditis elegans. However, the precise mechanism of inhibition is still poorly understood. Here we report on an in vit...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200851d
更新日期:2011-09-06 00:00:00
abstract::Excitation energy transfer studies were carried out to determine the distance between the adenosinetriphosphatase (ATPase) site and a unique "fast-reacting" sulfhydryl (referred to as SH1) in myosin subfragment 1. The fluorescent moiety of the probe N-(iodoacetyl)-N'-(5-sulfo-1-naphthyl)ethylene-diamine was used as th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00520a035
更新日期:1981-08-18 00:00:00
abstract::The Escherichia coli repressor of biotin biosynthesis is both a biotin ligase and the repressor of transcriptional initiation at the biotin biosynthetic operon. The small molecule, biotinyl-5'-adenylate (bio-5'-AMP), is the intermediate in the biotin ligation reaction and the positive allosteric effector for sequence-...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00189a041
更新日期:1994-06-14 00:00:00
abstract::The toll that Streptococcus pneumoniae exacts on the welfare of humanity is enormous. This organism claims the lives of approximately 3700 people daily, the majority of whom are children below the age of 5, and the situation could worsen due to the increasing incidence of pernicious, multiple-antibiotic-resistant stra...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi048075t
更新日期:2004-12-28 00:00:00
abstract::Filamin A (FLNA) is a ubiquitously expressed actin cross-linking protein and a scaffold of numerous binding partners to regulate cell proliferation, migration, and survival. FLNA is a homodimer, and each subunit has an N-terminal actin-binding domain followed by 24 immunoglobulin-like repeats (R). FLNA mediates mechan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b00100
更新日期:2019-11-26 00:00:00
abstract::Complete resonance assignments of nonexchangeable base protons and sugar protons in d-GGTACGCGTACC at 500 MHz have been obtained by two-dimensional correlated spectroscopy (COSY) and nuclear Overhauser enhancement spectroscopy (NOESY). The characteristic phase-sensitive multiplet patterns of the ntrasugar cross peaks ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00410a050
更新日期:1988-05-17 00:00:00
abstract::It has been suggested that the down-regulation of hepatic HMG-CoA reductase by dietary cholesterol requires modification of the cholesterol molecule before it can exert its suppressive action. In a recent study [Lund, E., Breuer, O., & Björkhem, I. (1992) J. Biol. Chem. 267, 25092-25097], we showed that side-chain hyd...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00167a038
更新日期:1994-01-11 00:00:00
abstract::The spin equilibria of several derivatives of human methemoglobin were probed by resonance Raman scattering. The intensity of lines in the Raman spectrum gives a measure of the high-spin (S = 5/2) to low-spin (S = 1/2) ratio which agrees well with the spin equilibria determined from direct magnetic susceptibility meas...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00438a056
更新日期:1989-06-13 00:00:00
abstract::DNA polymerases slide on DNA during replication, and the interface must be mobile for various conformational changes. The role of lubricant interfacial water is not understood. In this report, we systematically characterize the water dynamics at the interface and in the active site of a tight binding polymerase (pol β...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500810a
更新日期:2014-08-26 00:00:00
abstract::Aspartoacylase catalyzes the deacetylation of N-acetylaspartic acid (NAA) to produce acetate and L-aspartate and is the only brain enzyme that has been shown to effectively metabolize NAA. Although the exact role of this enzymatic reaction has not yet been completely elucidated, the metabolism of NAA appears to be nec...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi052608w
更新日期:2006-05-09 00:00:00
abstract::Although G protein-coupled receptor (GPCR) kinases (GRKs) have been shown to mediate desensitization of numerous GPCRs in studies using cellular expression systems, their function under physiological conditions is less well understood. In the current study, we employed various strategies to assess the effect of inhibi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801056w
更新日期:2008-09-02 00:00:00
abstract::In iron-deficient conditions, Azomonas macrocytogenes ATCC 12334 excretes a fluorescent siderophore called azoverdin, which is composed of a six-amino-acid peptide chain linked to a chromophore. Azoverdin chelates iron(III) very strongly, solubilizing it and transporting it back into the cells using an outer-membrane ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025990a
更新日期:2002-10-15 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::The binding of Ca2+ and the resulting change in catalytic specificity that allows phosphorylation of the calcium ATPase of sarcoplasmic reticulum by ATP were examined by measuring the amount of phosphoenzyme formation from [32P]ATP, or 45Ca incorporation into vesicles, after the simultaneous addition of ATP and EGTA a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00423a018
更新日期:1988-11-15 00:00:00
abstract::Glycopeptidolipids (GPLs) are specific constituents of mycobacteria known as opportunistic pathogens. The influence of the carbohydrate moiety on GPL-induced membrane alterations was examined with GPLs bearing 1-5 sugar residues (GPL-1 to GPL-5) and a sulfated GPL (S-GPL-2). GPLs decreased the ADP/O ratio and increase...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00189a006
更新日期:1994-06-14 00:00:00
abstract::Horse heart cytochrome c has been modified by 8-azido-ATP and the electron-transfer activity of the modified cytochrome c's to bovine heart cytochrome c oxidase (CcO) under physiological ionic strengths has been studied by the laser flash photolysis technique with 5-deazariboflavin and EDTA as the electron donor. The ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00008a035
更新日期:1995-02-28 00:00:00
abstract::Enolase is a glycolytic metalloenzyme involved in carbon metabolism. The advantage of targeting enolase lies in its essentiality in many biological processes such as cell wall formation and RNA turnover and as a plasminogen receptor. We initially used a DARTS assay to identify enolase as a target in Escherichia coli. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b01298
更新日期:2019-03-05 00:00:00
abstract::RNA covalently linked to double-stranded RNA (dsRNA) is preferentially degraded in extracts of interferon-treated HeLa cells [Nilsen, T. W., & Baglioni, C. (1979) Proc. Natl. Acad. Sci. U.S.A. 76, 2600-2604]. The size of the dsRNA required for this preferential degradation has been determined by annealing poly(I) of k...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00565a018
更新日期:1980-11-25 00:00:00
abstract::The side chains of the interacting pair Asp237(helix VII)-Lys358(helix XI) or Asp240(helix VII)-Lys319(helix X) in the lactose permease of Escherichia coli were extended by replacement with Glu and/or Arg or by site-specific derivatization of single-Cys replacement mutants. Iodoacetic acid was used to carboxymethylate...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00089a019
更新日期:1993-09-28 00:00:00
abstract::Structures of glycopeptides obtained by exhaustive Pronase digestion of high molecular weight (1.7 X 10(5)) salmon egg polysialoglycoprotein have been elucidated. Six principal glycopeptides isolated by gel chromatography and DEAE-Sephadex A-25 chromatography in the absence or presence of borate ion were analyzed for ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00341a029
更新日期:1985-09-24 00:00:00
abstract::The tiny picoalga, Ostreococcus tauri, originating from the Thau Lagoon is a member of the marine phytoplankton. Because of its highly reduced genome and small cell size, while retaining the fundamental requirements of a eukaryotic photosynthetic cell, it became a popular model organism for studying photosynthesis or ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.8b01200
更新日期:2019-04-09 00:00:00
abstract::Tyr71 is an invariant residue in all known sequences of tyrosine phenol-lyase (TPL). The substitution of Tyr71 in TPL by phenylalanine results in a mutant Y71F TPL with no detectable activity (greater than 3 x 10(5)-fold reduction) for beta-elimination of L-tyrosine. Y71F TPL can react with S-alkylcysteines, but these...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00038a023
更新日期:1995-09-26 00:00:00
abstract::Information on the secondary structure and interactions of RNA is important to understand the biological function of RNA as well as in applying RNA as a tool for therapeutic purposes. Recently, the isoenergetic microarray mapping method was developed to improve the prediction of RNA secondary structure. Herein, for th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi200463p
更新日期:2011-09-06 00:00:00
abstract::alpha5beta1 integrin can occupy several distinct conformational states which support different strengths of binding to fibronectin [García, A. J., et al. (1998) J. Biol. Chem. 273, 34710-34715]. Using a model system in which specific activating monoclonal antibodies were used to achieve uniform activated states, the b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025752f
更新日期:2002-07-23 00:00:00
abstract::Low molecular weight protein tyrosine phosphatases (LMW-PTPs) are small enzymes that are ubiquitous in many organisms. They are important in biological processes such as cell proliferation, adhesion, migration, and invasiveness. LMW-PTP is expressed in mammalian cells as two isoforms (IF1 and IF2) originating through ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0620858
更新日期:2007-05-29 00:00:00
abstract::Cholesterol and its hemisuccinate and sulfate derivatives are widely used in studies of purified membrane proteins but are difficult to solubilize in aqueous solution, even in the presence of detergent micelles. Other cholesterol derivatives do not form conventional micelles and lead to viscous solutions. To address t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101334j
更新日期:2010-11-09 00:00:00
abstract::The iron-chelating peptide vibriobactin of the pathogenic Vibrio cholerae is assembled by a four-subunit nonribosomal peptide synthetase complex, VibE, VibB, VibH, and VibF, using 2,3-dihydroxybenzoate and L-threonine as precursors to two 2,3-dihydroxyphenyl- (DHP-) methyloxazolinyl groups in amide linkage on a norspe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi010937s
更新日期:2001-09-04 00:00:00
abstract::Translesion synthesis (TLS) is a mutagenic branch of cellular DNA damage tolerance that enables bypass replication over DNA lesions carried out by specialized low-fidelity DNA polymerases. The replicative bypass of most types of DNA damage is performed in a two-step process of Rev1/Polζ-dependent TLS. In the first ste...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b01282
更新日期:2016-04-05 00:00:00