Abstract：
:Manganese superoxide dismutase (MnSOD) cycles between the Mn(II) and Mn(III) states during the catalyzed disproportionation of O(2)(*-), a catalysis that is limited at micromolar levels of superoxide by a peroxide-inhibited complex with the metal. We have investigated the role in catalysis and inhibition of the conserved residue Trp161 which forms a hydrophobic side of the active site cavity of MnSOD. Crystal structures of mutants of human MnSOD in which Trp161 was replaced with Ala or Phe showed significant conformational changes on adjacent residues near the active site, particularly Gln143 and Tyr34 which in wild-type MnSOD participate in a hydrogen bond network believed to support proton transfer during catalysis. Using pulse radiolysis and observing the UV absorbance of superoxide, we have determined rate constants for the catalytic dismutation of superoxide. In addition, the rates of formation and dissociation of the product-inhibited complex of these mutants were determined by direct observation of the characteristic visible absorption of the oxidized and inhibited states. Catalysis by W161A and W161F MnSOD was associated with a decrease of at least 100-fold in the catalytic rate of reduction of superoxide, which then promotes a competing pathway leading to product inhibition. The structural changes caused by the mutations at position 161 led to small changes, at most a 6-fold decrease, in the rate constant for formation of the inhibited complex. Solvent hydrogen isotope effects support a mechanism in which formation of this complex, presumably the peroxide dianion bound to the manganese, involves no rate-contributing proton transfer; however, the dissociation of the complex requires proton transfer to generate HO(2)(-) or H2O2.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Hearn AS,Stroupe ME,Cabelli DE,Lepock JR,Tainer JA,Nick HS,Silverman DNdoi
10.1021/bi011047fsubject
Has Abstractpub_date
2001-10-09 00:00:00pages
12051-8issue
40eissn
0006-2960issn
1520-4995pii
bi011047fjournal_volume
40pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract：:The discovery of three mutants in the -synuclein (alphaSyn) gene and the identification of alphaSyn as the major component of Lewy body have opened a new field for understanding the pathogenesis of Parkinson's disease (PD). AlphaSyn is a natively unfolded protein with unknown function and unspecified conformational he...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi062068i
更新日期：2007-01-16 00:00:00
abstract：:c-Jun and c-Fos belong to the bZIP class of transcriptional activator proteins, many of which have been implicated in the neoplastic transformation of cells. We are interested in engineering dominant-negative leucine zipper (LZ) peptides as a means of sequestering these proteins in vivo in order to suppress their tran...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi952817o
更新日期：1996-07-16 00:00:00
abstract：:The membrane topology of the human apical sodium-dependent bile acid transporter (hASBT) remains unresolved. Whereas N-glycosylation analysis favors a 7 transmembrane (TM) model, membrane insertion scanning supports a 9TM topology. In order to resolve this controversy, we used dual label epitope insertion to systemati...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi052202j
更新日期：2006-01-24 00:00:00
abstract：:Detailed analysis of factors governing high affinity antibody-antigen interactions yields important insight into molecular recognition and facilitates the design of functional antibody libraries. Here we describe comprehensive mutagenesis of the light chain complementarity determining regions (CDRs) of HIV-1 antibody ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi100293q
更新日期：2010-07-06 00:00:00
abstract：:Intracellular reduction of carcinogenic Cr(VI) generates Cr-DNA adducts formed through the coordination of Cr(III) to DNA phosphates (phosphotriester-type adduct). Here, we examined the role of Cr(III)-DNA adducts in mutagenesis induced by metabolism of Cr(VI) with cysteine. Reduction of Cr(VI) caused a strong oxidati...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0015459
更新日期：2001-01-16 00:00:00
abstract：:Surface plasmon resonance (SPR) spectroscopy has been used to follow incorporation and light-induced conformational changes in bovine rhodopsin reconstituted into an egg phosphatidylcholine bilayer deposited on a thin silver film. The magnitude of the SPR spectral changes caused by light varies with pH in a manner par...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00250a022
更新日期：1994-11-22 00:00:00
abstract：:All retroviruses package two copies of their genomes during virus assembly, both of which are required for strand transfer-mediated recombination during reverse transcription. Genome packaging is mediated by interactions between the nucleocapsid (NC) domains of assembling Gag polyproteins and an RNA packaging signal, ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi047639q
更新日期：2005-03-15 00:00:00
abstract：:The bovine prothrombin gene was characterized by Southern blot analysis of bovine genomic DNA using bovine prothrombin cDNA fragments as hybridization probes. These analyses suggested that the bovine genome contains a single prothrombin gene that is at least 10 kilobase pairs (kbp) in size. To characterize the gene mo...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00345a018
更新日期：1985-11-19 00:00:00
abstract：:The Vmax/Km (microM -1 min -1.) for bovine factor X activation by bovine factor IXa alpha, in the presence of sufficient [Ca2+] to saturate the initial reaction rate, was 0.007. When factor IXa beta was substituted for factor IXa alpha in this reaction, the Vmax/Km decreased to 0.001, suggesting that factor IXa alpha ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00286a007
更新日期：1983-08-16 00:00:00
abstract：:The electrons extracted from the CaMn(4) cluster during water oxidation in photosystem II are transferred to P(680)(+) via the redox-active tyrosine D1-Tyr161 (Y(Z)). Upon Y(Z) oxidation a proton moves in a hydrogen bond toward D1-His190 (His(Z)). The deprotonation and reprotonation mechanism of Y(Z)-OH/Y(Z)-O is of k...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi101364t
更新日期：2010-11-16 00:00:00
abstract：:The Ca2+-dependent, reversible, interaction of cyclic adenosine 3',5'-monophosphate (cAMP) phosphodiesterase with its activator has been used to purify the enzyme by affinity chromatography. Activator-dependent cAMP phosphodiesterase is only a minor component of the proteins specifically adsorbed in the presence of Ca...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00594a017
更新日期：1978-01-10 00:00:00
abstract：:The tRNA(His) guanylyltransferase (Thg1) catalyzes the incorporation of a single guanosine residue at the -1 position (G(-1)) of tRNA(His), using an unusual 3'-5' nucleotidyl transfer reaction. Thg1 and Thg1 orthologs known as Thg1-like proteins (TLPs), which catalyze tRNA repair and editing, are the only known enzyme...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi201397f
更新日期：2012-01-10 00:00:00
abstract：:The NO adducts of leghemoglobin (Lb) are implicated in biological processes, but only the adduct with ferrous Lb (Lb(II)NO) has been characterized previously. We report the first characterization of ferric nitrosylleghemoglobin (Lb(III)NO) and XAS experiments performed on frozen aqueous solutions of Lb(II)NO and Lb(II...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi990730n
更新日期：1999-12-14 00:00:00
abstract：:A high-resolution solution conformation of a novel conotoxin, [Pro 7,13] alpha A-conotoxin PIVA, GCCGSYPNAACHPCSCKDROSYCGQ-NH2, has been determined by two-dimensional 1H NMR methods and distance geometry calculations. The total of 324 NOE-derived interproton distance restraints including 33 long-range NOE restraints a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi962301k
更新日期：1997-02-18 00:00:00
abstract：:Complete 1H NMR sequential assignments have been made for copper(I)- and silver (I)-substituted metallothionein (MT) from Saccharomyces cerevisiae using standard 2D 1H NMR methods. The fingerprint region of the COSY spectrum of both metalloproteins shows a doubling of a few backbone proton resonances from residue K41 ...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00077a032
更新日期：1993-07-06 00:00:00
abstract：:The structure of the ca. 250 amino acid hormone binding domain of the human estrogen receptor (hER-LBD), expressed in E. coli and purified as a complex with estradiol, has been probed by selective proteolysis, with analysis of the protein fragments both by classical methods (SDS-PAGE and Edman N-terminal sequencing) a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00039a016
更新日期：1995-10-03 00:00:00
abstract：:Peptide-membrane interactions are important for understanding the binding, partitioning, and folding of membrane proteins; the activity of antimicrobial and fusion peptides; and a number of other processes. We describe molecular dynamics simulations (10-25 ns) of two pentapeptides Ace-WLXLL (with X = Arg or Lys side c...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi027001j
更新日期：2003-08-05 00:00:00
abstract：:SHP (short heterodimer partner) is an orphan nuclear receptor, first described for its interaction with nuclear receptors. This study explores a new way of inhibiting the androgen-signaling pathway. We demonstrated that SHP inhibited up to 97% of AR-induced activity. Characterization of AR/SHP interaction provided evi...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi011384o
更新日期：2001-12-18 00:00:00
abstract：:The thermal unfolding of rabbit skeletal heavy meromyosin (HMM), myosin subfragment 1, and subfragment 2 has been studied by differential scanning calorimetry (DSC). Two distinct endotherms are observed in the DSC scan of heavy meromyosin. The first endotherm, with a Tm of 41 degrees C at pH 7.9 in 0.1 M KCl, is assig...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00462a018
更新日期：1990-03-13 00:00:00
abstract：:Neuroligins 1-4 are postsynaptic transmembrane proteins capable of initiating presynaptic maturation via interactions with beta-neurexin. Both neuroligins and beta-neurexins have alternatively spliced inserts in their extracellular domains. Using analytical ultracentrifugation, we determined that the extracellular dom...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi0614131
更新日期：2006-10-24 00:00:00
abstract：:The thermal denaturation of the cupredoxin plastocyanin (PC) from spinach has been studied with the aim of improving the understanding of factors involved in the conformational stability of antiparallel beta-sheet proteins. Studies using differential scanning calorimetry have been complemented with nuclear magnetic re...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi034371e
更新日期：2003-09-02 00:00:00
abstract：:The effect of mutating Gly 478 to Ala in rat cytochrome P450 2B1 on the metabolism of N-benzyl-1-aminobenzotriazole was investigated. The 7-ethoxy-4-(trifluoromethyl)coumarin O-deethylation activity of the wild-type enzyme was completely inactivated by incubating with 1 microM BBT. The G478A mutant, however, was not i...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi971064y
更新日期：1997-09-30 00:00:00
abstract：:Tandem calponin-homology (CH) domains are the most common actin-binding domains in proteins. However, structural principles underlying their function are poorly understood. These tandem domains exist in multiple conformations with varying degrees of inter-CH-domain interactions. Dystrophin and utrophin tandem CH domai...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/acs.biochem.5b00741
更新日期：2015-09-08 00:00:00
abstract：:DrrA and DrrB proteins form an ATP-dependent efflux pump for doxorubicin and daunorubicin in Streptomyces peucetius. DrrA, the catalytic subunit, forms a complex with the integral membrane protein DrrB. Previous studies have provided evidence for strong interaction between these two proteins, which was found to be cri...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi701699a
更新日期：2008-03-04 00:00:00
abstract：:In an effort to gain greater insight into the molecular mechanism of the electron-transfer reactions of cytochrome b(5), the bovine cytochrome b(5)-horse cytochrome c complex has been investigated by high-resolution multidimensional NMR spectroscopy using (13)C, (15)N-labeled cytochrome b(5) expressed from a synthetic...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi001129o
更新日期：2000-11-21 00:00:00
abstract：:The interaction of glutamyl-tRNA synthetase with tRNAGlu2 has been studied. The enzyme was purified to apparent homogeneity, and consists of a single chain with a molecular weight of 59 000. The sedimentation coefficient (sdegrees20,w) was found to be 3.7 S and suggests this enzyme is quite asymmetric. The enzyme bind...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00664a032
更新日期：1976-09-21 00:00:00
abstract：:The major carbohydrate fragment from the lipophosphoglycan of Leishmania donovani was generated by mild acid hydrolysis (0.02 N HCl, 5 min, 100 degrees C) and purified by chromatography on DE-52 cellulose and thin layer. By a combination of analyses including gas-liquid chromatography-mass spectrometry and 1H NMR, the...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00393a042
更新日期：1987-09-22 00:00:00
abstract：:Dendritic cell-specific intracellular adhesion molecule-3-grabbing nonintegrin (DC-SIGN) is a C-type lectin highly expressed on the surface of antigen-presenting dendritic cells. DC-SIGN mediates interactions among dendritic cells, pathogens, and a variety of epithelia, myeloid cells, and endothelia by binding to high...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi5005014
更新日期：2014-09-09 00:00:00
abstract：:The oxygen transfer to p-hydroxybenzoate catalyzed by p-hydroxybenzoate hydroxylase (PHBH) has been shown to occur via a C4a-hydroperoxide of the flavin. Two factors are likely to be important in facilitating the transfer of oxygen from the C4a-hydroperoxide to the substrate. (a) The positive electrostatic potential o...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi010892v
更新日期：2001-07-31 00:00:00
abstract：:Chemosensory cilia isolated from the olfactory epithelium of Rana catesbeiana were solubilized with Lubrol PX in the presence of supplementary lipid, forskolin, and sodium fluoride. Subsequent removal of the detergent by adsorption onto Biobeads SM2 results in the formation of proteoliposomes that display forskolin- a...
journal_title：Biochemistry
pub_type： 杂志文章
doi：10.1021/bi00417a040
更新日期：1988-08-23 00:00:00
