Abstract:
:Charybdotoxin (ChTX) and iberiotoxin (IbTX) are highly charged peptidyl toxins which exhibit 68% sequence identity and share a similar three-dimensional structure. Despite these structural similarities, IbTX and ChTX differ in their selectivity for two types of potassium channels; large conductance calcium-activated potassium (maxi-K) channels and slowly inactivating voltage-gated (Kv1.3) potassium channels. ChTX blocks with high affinity both maxi-K and Kv1.3 channels, while IbTX blocks the maxi-K but not the voltage-gated channel. To identify regions of the toxins which impart this this selectivity, we have constructed by solid-phase synthesis two chimeric toxins, ChTX1-19IbTX20-37 (Ch-IbTX) and IbTX1-19ChTX20-37 (Ib-ChTX), as well as a truncated peptide, ChTX7-37. These peptides were assayed for their ability to inhibit [125I]ChTX binding in sarcolemmal vesicles from smooth muscle (maxi-K binding) and [125I]ChTX binding to plasma membranes from brain (Kv1.3 binding). The ability of the peptides to block the maxi-K channel was determined from recordings of single maxi-K channels incorporated into planar lipid bilayers. Block of Kv1.3 was determined from recordings of whole cell currents in Xenopus oocytes injected with mRNA encoding the cloned Kv1.3 channel. Both chimeric toxins inhibited [125I]ChTX binding to sarcolemmal membranes from smooth muscle, and they both blocked the maxi-K channel in planar lipid bilayers. In contrast, [125I]ChTX binding in brain and Kv1.3 currents expressed in oocytes were inhibited only by the chimera Ib-ChTX.(ABSTRACT TRUNCATED AT 250 WORDS)
journal_name
Biochemistryjournal_title
Biochemistryauthors
Giangiacomo KM,Sugg EE,Garcia-Calvo M,Leonard RJ,McManus OB,Kaczorowski GJ,Garcia MLdoi
10.1021/bi00060a030subject
Has Abstractpub_date
1993-03-09 00:00:00pages
2363-70issue
9eissn
0006-2960issn
1520-4995journal_volume
32pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The mechanism of N-methyltryptophan oxidase, a flavin-dependent amine oxidase from Escherichia coli, was studied using a combination of kinetic isotope effects and theoretical calculations. The 15(kcat/Km) kinetic isotope effect for sarcosine oxidation is pH-dependent with a limiting value of 0.994-0.995 at high pH. D...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi700482h
更新日期:2007-06-26 00:00:00
abstract::Dynamic light scattering measurements were carried out on secretin in aqueous solution (2 mM; pH 5.0). The results indicated that the molecule exists as a fairly compact hexamer under these solution conditions. Secondary structural properties of the secretin hexameric complex were evaluated using CD and NMR spectrosco...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980701x
更新日期:1998-12-01 00:00:00
abstract::The functional role of distinct phospholipid subclasses and molecular species in modulating gramicidin-mediated K+ flux was characterized through quantification of changes in the fluorescence intensity of ion specific fluorescent probes encapsulated inside vesicles comprised of individual molecular species of plasmeny...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00022a008
更新日期:1995-06-06 00:00:00
abstract::Detection of specific reaction products is a powerful approach for dissecting out pathways that mediate oxidative damage in vivo. Eosinophil peroxidase (EPO), an abundant protein secreted from activated eosinophils, has been implicated in promoting oxidative tissue injury in conditions such as asthma, allergic inflamm...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi982401l
更新日期:1999-03-23 00:00:00
abstract::PKC phosphorylation regulates PITX2 DNA binding and transcriptional activity. Mutation of individual PKC sites demonstrates the functional regulation of PITX2 through phosphorylation. Immunoprecipitation of PITX2 and a PITX2 PKC mutant protein reveal specific in vivo phosphorylation by PKC in transfected cells. The tr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi048362x
更新日期:2005-03-15 00:00:00
abstract::Significant concentrations (1-10 mM) of nickel(II) were found in solution after incubation of the potent carcinogen nickel subsulfide in 0.05 M Tris-HCl, pH 7.4, solutions containing DNA, rat liver microsomes, and NADPH. The presence of NADPH decreased the rate of solubilization of nickel subsulfide. The solubilized n...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00533a030
更新日期:1982-02-16 00:00:00
abstract::The structure of human epidermal growth factor (EGF, 53 amino acids) comprises three distinct loops (A, B, and C) connected correspondingly by the three native disulfide bonds, Cys(6)-Cys(20), Cys(14)-Cys(31), and Cys(33)-Cys(42). The connection of Cys(6) and Cys(20) forming the N-terminal A loop is essential for the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi051399c
更新日期:2005-11-15 00:00:00
abstract::The kinetics of the interconversions of the subgel and gel phases in dipalmitoylphosphatidylcholine have been studied by using differential dilatometry, differential scanning calorimetry (DSC), and neutral buoyancy centrifugation as a function of incubation temperature and deuteriation of the solvent. As seen by other...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00388a016
更新日期:1987-07-14 00:00:00
abstract::Methylenetetrahydrofolate dehydrogenase-cyclohydrolase (FolD) catalyzes interconversion of 5,10-methylene-tetrahydrofolate and 10-formyl-tetrahydrofolate in the one-carbon metabolic pathway. In some organisms, the essential requirement of 10-formyl-tetrahydrofolate may also be fulfilled by formyltetrahydrofolate synth...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.5b00400
更新日期:2015-06-09 00:00:00
abstract::More than 100 distinct mutations in the gene CuZnSOD encoding human copper-zinc superoxide dismutase (CuZnSOD) have been associated with familial amyotrophic lateral sclerosis (fALS), a fatal neuronal disease. Many studies of different mutant proteins have found effects on protein stability, catalytic activity, and me...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi500606j
更新日期:2015-01-20 00:00:00
abstract::The derivatives of calf thymus DNA in which n-butylamine is covalently attached as described in the preceding paper in this series [Chen, C. Y., Pheiffer, B. H., Zimmerman, S. B., & Hanlon, S. (1983) Biochemistry (preceding paper in this issue)] were examined by Raman spectroscopy. As previously mentioned, these compl...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00289a021
更新日期:1983-09-27 00:00:00
abstract::Kinetic studies of the effect of addition of Co2+ or Mn2+ to a highly purified dipeptidase from Ehrlich-Lettré mouse ascites tumor cells show that these metals specifically activate the hydrolyses of certain classes of dipeptides. This enzyme was previously (S. Hayman and E. K. Patterson, 1971, J. Biol. Chem. 246, 660...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00690a018
更新日期:1975-09-23 00:00:00
abstract::A nine-base oligodeoxyribonucleotide complementary to bases 2497-2505 of 23S rRNA was hybridized to both 50S subunits and 70S ribosomes. The binding of the probe to the ribosome or ribosomal subunits was assayed by nitrocellulose filtration and by sucrose gradient centrifugation techniques. The location of the hybridi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00428a073
更新日期:1989-01-24 00:00:00
abstract::S100 beta is a calcium-binding protein, which regulates the activities of several enzymes and inhibits the phosphorylation of a variety of protein kinase C substrates in a calcium-dependent manner. The protein was recently found to activate a retinal membrane guanylate cyclase, and in this paper, we report that it inh...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9802115
更新日期:1998-07-28 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
abstract::To develop molecules capable of directly probing the catechol binding region of the beta(2)-adrenergic receptor (beta(2)AR), novel benzophenone- and fluorenone-based beta(2)AR antagonists were prepared as potential photoaffinity probes. While the benzophenone-containing ligands bound with relatively modest affinity, o...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi001342k
更新日期:2000-10-24 00:00:00
abstract::Urea lesions are formed in DNA because of free radical damage of the thymine base, and their occurrence in DNA blocks DNA polymerases, which has deleterious consequences. Recently, it has been shown that urea is capable of forming hydrogen bonding and stacking interactions with nucleobases, which are responsible for t...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00309
更新日期:2016-10-11 00:00:00
abstract::Metabolomics is a rapidly growing field of research used in the identification and quantification of the small molecule metabolites within an organism, thereby providing insights into cell metabolism and bioenergetics as well as processes important in clinical medicine, such as disposition of pharmaceutical compounds....
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/bi400060e
更新日期:2013-06-04 00:00:00
abstract::Plasma membrane and vesicular transporters for the biogenic amines, dopamine, norepinephrine, and serotonin, represent a group of proteins that play a crucial role in the regulation of neurotransmission. Clinically, mono amine transporters are the primary targets for the actions of many therapeutic agents used to trea...
journal_title:Biochemistry
pub_type: 杂志文章,评审
doi:10.1021/bi200405c
更新日期:2011-08-30 00:00:00
abstract::The enzyme As(III) S-adenosylmethionine methyltransferase (EC 2.1.1.137) (ArsM or AS3MT) is found in members of every kingdom, from bacteria to humans. In these enzymes, there are three conserved cysteine residues at positions 72, 174, and 224 in the CmArsM orthologue from the thermophilic eukaryotic alga Cyanidioschy...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi201500c
更新日期:2012-02-07 00:00:00
abstract::Succinyl-CoA synthetase of Escherichia coli is an alpha 2 beta 2 protein containing active sites at the interfaces between alpha- and beta-subunits. The alpha-subunit contains a histidine residue that is phosphorylated during the reaction. The beta-subunit binds coenzyme A and probably succinate [see Nishimura, J. S. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00370a061
更新日期:1986-11-04 00:00:00
abstract::Spike glycoprotein of SARS coronavirus (S protein) plays a pivotal role in SARS coronavirus (SARS_CoV) infection. The immunological fragment of the S protein (Ala251-His641, SARS_S1b) is believed to be essential for SARS_CoV entering the host cell through S protein-ACE-2 interaction. We have quantitatively characteriz...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0482396
更新日期:2005-02-08 00:00:00
abstract::High-resolution, solid-state 15N NMR has been used to study the chemical shift anisotropies of the Schiff bases in bacteriorhodopsin (bR) and in an extensive series of model compounds. Using slow-spinning techniques, we are able to obtain sufficient rotational sideband intensity to determine the full 15N chemical shif...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00434a033
更新日期:1989-04-18 00:00:00
abstract::Bacteriophage lambda protein phosphatase (lambdaPP) is a member of a large family of metal-containing phosphoesterases, including purple acid phosphatase, protein serine/threonine phosphatases, 5'-nucleotidase, and DNA repair enzymes such as Mre11. lambdaPP can be activated several-fold by various divalent metal ions,...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi026317o
更新日期:2002-12-24 00:00:00
abstract::Misaligned structures can result from strand slippage during DNA replication and, if not repaired, would lead to mutations. Previously, we showed that strand slippage can occur upon misincorporation of a dNTP opposite thymine and cytosine templates, resulting in a misaligned structure with a T- or C-bulge. The formati...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9014049
更新日期:2009-12-08 00:00:00
abstract::A procedure for universal 13C and/or 15N labeling of microbial peptides which are produced by fermentation in complex media and its application to two food-preserving bacteriocins from lactic acid bacteria are described. Isotopic enrichment of nisin A (from Lactococcus lactis) and of leucocin A (from Leuconostoc gelid...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00052a039
更新日期:1993-01-12 00:00:00
abstract::Coordinate regulation of PARP-1 and -2 and PARG is required for cellular responses to genotoxic stress. While PARP-1 and -2 are regulated by DNA breaks and covalent modifications, mechanisms of PARG regulation are poorly understood. We report here discovery of a PARG regulatory segment far removed linearly from residu...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi100973m
更新日期:2010-09-07 00:00:00
abstract::We have used enzymic and chemical probes to search for altered DNA conformations in the 5' flanking region of the gene for a high mobility group protein (HMG-T) from trout. This search was conducted in order to identify potential genetic elements that might be involved in the transcriptional control of the HMG-T gene....
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00402a012
更新日期:1988-01-26 00:00:00
abstract::Amyloid deposition of human islet amyloid polypeptide (hIAPP) in the islets of Langerhans is closely associated with the pathogenesis of type II diabetes mellitus. Despite substantial evidence linking amyloidogenic hIAPP to loss of β-cell mass and decreased pancreatic function, the molecular mechanism of hIAPP cytotox...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi300542g
更新日期:2012-09-04 00:00:00
abstract::Interaction of a mitochondria-specific anionic phospholipid, cardiolipin (CL), with an intermembrane protein, cytochrome c (cyt c), yields a peroxidase complex. During apoptosis, the complex induces accumulation of CL oxidation products that are essential for detachment of cyt c from the mitochondrial membrane, induct...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi801507s
更新日期:2008-12-23 00:00:00