Abstract:
:The alpha-conotoxins MI and GI display stronger affinities for the alphagamma agonist site on the Torpedo californica electrocyte nicotinic acetylcholine receptor (ACHR) than for the alphadelta agonist site, while alpha-conotoxin SI binds with the same affinity to both sites. Prior studies reported that the arginine at position 9 on GI and the tyrosine at position 111 on the receptor gamma subunit were responsible for the stronger alphagamma affinities of GI and MI, respectively. This study was undertaken to determine if the alpha-conotoxin midchain cationic residues interact with Torpedo gammaY111. The findings show that lysine 10 on MI is responsible for the alphagamma selectivity of MI and confirm the previously reported importance of R9 on GI and on the SI analogue, SIP9R. The results also show that gammaY111 contributes substantially to the selective alphagamma high affinity of all three peptides. Double-mutant cycle analyses reveal that, in the alphagamma site, K10 on MI and R9 on SIP9R interact with the aromatic ring of gammaY111 to stabilize the high-affinity complex, while in contrast, R9 on GI does not. The substitution of Y for R at position 113 on the delta subunit converts the alphadelta site into a high-affinity site for MI, GI, and SIP9R through the interacting of deltaY113 with K10 on MI and with R9 on both GI and SIP9R. The overall data show that the residues in the two sites with which MI interacts, other than at gamma111/delta113, are either the same or similar enough to exert equivalent effects on MI, indicating that MI binds in the same orientation at the alphagamma and alphadelta sites. Similar findings show that SIP9R probably also binds in the same orientation at the wild-type alphagamma and alphadelta sites. The finding that R9 on GI interacts closely with deltaR113Y but not with gammaY111 means that GI binds in different orientations at the alphagamma and alphadelta sites. This report also discusses the molecular basis of the difference in the MI high-affinity sites on Torpedo and embryonic mouse muscle ACHRs.
journal_name
Biochemistryjournal_title
Biochemistryauthors
Vélez-Carrasco W,Valdés S,Agresar L,Lettich A,Guerra AY,Hann RMdoi
10.1021/bi030248bsubject
Has Abstractpub_date
2004-10-05 00:00:00pages
12700-8issue
39eissn
0006-2960issn
1520-4995journal_volume
43pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::Monomeric sarcosine oxidase (MSOX) binds the L-proline zwitterion (pKa = 10.6). The reactive substrate anion is generated by ionization of the ES complex (pKa = 8.0). Tyr317 was mutated to Phe to determine whether this step might involve proton transfer to an active site base. The mutation does not eliminate the ioniz...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi051898d
更新日期:2005-12-27 00:00:00
abstract::The diversity, abundance, and DNA sequence representation of poly(adenylic acid) containing RNA derived from cells of Achlya ambisexualis cultured in defined and undefined media have been determined. The kinetics of hybridization of polyadenylated RNA with complementary DNA were the same for both culture conditions an...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00597a025
更新日期:1978-02-21 00:00:00
abstract::Sufiredoxins (Srx) repair the inactivated forms of typical two-Cys peroxiredoxins (Prx) implicated in hydrogen peroxide-mediated cell signaling. The reduction of the cysteine sulfinic acid moiety within the active site of the Prx by Srx involves novel sulfur chemistry and the use of ATP and Mg(2+). The 1.65 A crystal ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi050131i
更新日期:2005-06-21 00:00:00
abstract::The structure of the subgel phase of dipalmitoylphosphatidylglycerol (DPPG) has been analyzed by X-ray diffraction techniques. Diffraction recorded from highly oriented DPPG specimens in the subgel phase extends to 2-A resolution. There are sharp lamellar reflections on the meridian, and other reflections lie on a ser...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00350a003
更新日期:1986-01-28 00:00:00
abstract::Pantothenate kinase (PanK) catalyzes the first step of the universal five-step coenzyme A (CoA) biosynthetic pathway. The recently characterized type III PanK (PanK-III, encoded by the coaX gene) is distinct in sequence, structure and enzymatic properties from both the long-known bacterial type I PanK (PanK-I, exempli...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi7018578
更新日期:2008-02-05 00:00:00
abstract::The DNA binding domain of the yeast transcription factor Mbp1 is a winged helix-turn-helix structure, with an extended DNA binding site involving C-terminal "tail" residues. The thermodynamics of the interaction of the DNA binding domain with its target DNA sequence have been determined using fluorescence anisotropy a...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi702339q
更新日期:2008-06-17 00:00:00
abstract::Glyoxylate carboligase (GCL) is a thiamin diphosphate (ThDP)-dependent enzyme, which catalyzes the decarboxylation of glyoxylate and ligation to a second molecule of glyoxylate to form tartronate semialdehyde (TSA). This enzyme is unique among ThDP enzymes in that it lacks a conserved glutamate near the N1' atom of Th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi300893v
更新日期:2012-10-09 00:00:00
abstract::Adipocyte lipid-binding protein (ALBP) is the adipocyte member of an intracellular hydrophobic ligand-binding protein family. ALBP is phosphorylated by the insulin receptor kinase upon insulin stimulation. The crystal structure of recombinant murine ALBP has been determined and refined to 2.5 A. The final R factor for...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00128a024
更新日期:1992-04-07 00:00:00
abstract::The kinetics of the phospholipase A2-catalyzed hydrolysis of bilayer vesicles and mixed micelles of several oxyglycero and thioglycero analogues of phospholipids have been studied. The results with vesicles show that, depending on the source of the enzyme, the rates of hydrolysis of the oxy-containing long-chain phosp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00149a014
更新日期:1992-09-01 00:00:00
abstract::Association of the human papillomavirus (HPV) E2 protein with its palindromic DNA-binding site is a necessary step for transcriptional trans-activation. To study the interaction between DNA and E2, the carboxyl-terminal domain of HPV-11 E2 protein (E2C) was expressed in Escherichia coli and purified to homogeneity. Th...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi960447d
更新日期:1996-07-30 00:00:00
abstract::We have used diethyl pyrocarbonate (DEP), which carbethoxylates adenine bases, and dimethyl sulfate (DMS), which methylates guanine residues and single-stranded cytosines, to probe bases in open complexes between RNA polymerase and the lac UV5 promoter in vitro. We compared the kinetics of reactivity between bases in ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00436a040
更新日期:1989-05-16 00:00:00
abstract::The effects of various compounds such as the transport substrate ADP and the transport inhibitors carboxyatractyloside (CATR) and bongkrekic acid (BKA) on the labeling of cysteine residues in the ADP/ATP carrier of bovine heart submitochondrial particles by the SH reagent eosin-5-maleimide (EMA) were studied. Of the f...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00198a019
更新日期:1994-08-16 00:00:00
abstract::The composition of the molybdate-stabilized glucocorticoid receptor (GR) complex has been investigated with a monoclonal antibody against the steroid-binding Mr 94 000 (94K) GR protein. It was concluded that one antibody molecule binds one 94K GR molecule. This finding constituted the basis for calculating the number ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00344a041
更新日期:1985-11-05 00:00:00
abstract::Thymine DNA glycosylase (TDG) is a base excision repair enzyme with key functions in epigenetic regulation. Performing a critical step in a pathway for active DNA demethylation, TDG removes 5-formylcytosine and 5-carboxylcytosine, oxidized derivatives of 5-methylcytosine that are generated by TET (ten-eleven transloca...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b00982
更新日期:2016-11-15 00:00:00
abstract::Solvent reorganization can contribute significantly to the energetics of protein-protein interactions. However, our knowledge of the magnitude of the energetic contribution is limited, in part, by a dearth of quantitative experimental measurements. The biotin repressor forms a homodimer as a prerequisite to DNA bindin...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi400952m
更新日期:2013-09-24 00:00:00
abstract::Macromolecular protease inhibitors and camelid single-domain antibodies achieve their enzymic inhibition functions often through protruded structures that directly interact with catalytic centers of targeted proteases. Inspired by this phenomenon, we constructed synthetic human antibody libraries encoding long CDR-H3s...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.0c00690
更新日期:2020-10-13 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::DNA containing short sequences of the form (dA)n.(dT)n can exhibit pronounced degrees of stable curvature of the helix axis, provided that these homooligomeric stretches are approximately in phase with the helix repeat. However, the precise origin of this effect is unknown. We have observed that pyrimidine 5-methyl gr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00460a003
更新日期:1990-02-27 00:00:00
abstract::NSC 613862 (S)-(-) and NSC 613863 (R)-(+) are the two chiral isomers of ethyl-5-amino-2-methyl-1,2-dihydro-3-phenylpyrido[3, 4-b]pyrazin-7-yl carbamate. Both compounds bind to tubulin in a region that overlaps the colchicine site. They induce formation of abnormal polymers from purified GTP-Mg-tubulin, the active asse...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi970568t
更新日期:1998-01-13 00:00:00
abstract::A mouse monoclonal anti-7-(O-carboxymethyl)oximinoestradiol antibody was photoaffinity labeled with two cross-reactive 6alpha- and 6beta-(5-azido-2-nitrobenzoyl)amido[17alpha-3H]estradiol photoreagents (6alpha- and 6beta-ANBA-[17alpha-3H]estradiol). Covalently bound radioactivity was found exclusively on the light cha...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi962645a
更新日期:1997-06-24 00:00:00
abstract::Biological actions of insulin are initiated by activation of the insulin receptor tyrosine kinase. Protein tyrosine phosphatases (PTPases) PTP1B and PTPalpha are known to dephosphorylate the insulin receptor and may contribute to insulin resistance in diseases such as diabetes. We previously reported that overexpressi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9816103
更新日期:1999-01-05 00:00:00
abstract::Calcium and its receptor protein calmodulin function in the regulation of proliferation of mammalian cells. A 68 kDa calmodulin-specific binding protein was shown previously to be associated with growth factor-dependent progression of a variety of mammalian cells from G1 to S phase and to stimulate DNA synthesis in pe...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00012a002
更新日期:1995-03-28 00:00:00
abstract::Site-directed mutagenesis of the aspartate receptor of Salmonella typhimurium (Tars) at serine 68, a residue located within the aspartate binding pocket and at the subunit interface, identified this residue as an allosteric switch in this receptor. Substitutions at this position can affect both the type and degree of ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi961481v
更新日期:1996-11-26 00:00:00
abstract::Bovine brain adenylate cyclase was solubilized with 3-[(3-cholamidopropyl)dimethylammonio]-1-propanesulfonate (CHAPS), sodium cholate, sodium deoxycholate, or these detergents plus (NH4)2SO4. The specific activity of the extract obtained with 13 mM CHAPS alone was several times those of the other detergent extracts wi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00258a019
更新日期:1982-07-20 00:00:00
abstract::The monoamine transporter of the chromaffin granule membranes can be specifically labeled by the photoaffinity reagent 7-azido-8-[125I]iodoketanserin. The characteristics of the labeled protein have been investigated. Two-dimensional gel electrophoresis of the labeled membranes indicated a MW of about 70,000 and an is...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00122a012
更新日期:1992-02-25 00:00:00
abstract::Peripheral benzodiazepine receptors (PBR), first described more than 20 years ago, have been attributed with many putative functions including ones in cellular proliferation and cellular respiration. Hence, it is quite conceivable that deregulation of this receptor could lead to pathology. We and others have reported ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi030251v
更新日期:2004-09-28 00:00:00
abstract::The trifunctional dinuclear platinum compounds 1,2/c,c [[cis-PtCl(NH(3))(2)]mu-H(2)N(CH(2))(6)NH(2)[cis-PtCl(2)(NH(3))]](+) and 1,2/t,c [[trans-PtCl(NH(3))(2)]mu-H(2)N(CH(2))(6)NH(2)[cis-PtCl(2)(NH(3))]](+) contain a monofunctional platinum coordination sphere linked to a cis-[PtCl(2)(amine)(2)] moiety. The compounds ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi030243e
更新日期:2004-06-22 00:00:00
abstract::The effects of phosphorylation at Ser40 of rat tyrosine hydroxylase on the affinities of catechols have been determined with both the ferric and ferrous forms of the enzyme. Phosphorylation had no effect on the Ki value for the inhibition of the ferrous enzyme by either dopamine or DOPA when the initial rate of turnov...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi980582l
更新日期:1998-06-23 00:00:00
abstract::UDP-glucose:glycoprotein glucosyltransferase (UGT) is a soluble protein of the endoplasmic reticulum (ER) that operates as a gatekeeper for quality control by preventing transport of improperly folded glycoproteins out of the ER. We report the isolation of two cDNAs encoding human UDP-glucose:glycoprotein glucosyltran...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9916473
更新日期:2000-03-07 00:00:00
abstract::The structure of the copper site in oxidized and reduced Rhus vernicifera stellacyanin has been studied by X-ray absorption (XAFS) spectroscopy at different pH values. Data for the oxidized protein are consistent with the fourth ligand being an O- or N-donating ligand rather than a cysteine from the disulfide bridge. ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00001a026
更新日期:1995-01-10 00:00:00