Abstract:
:125I-Labeled enterotoxin from Clostridium perfringens was utilized to characterize the association of the enterotoxin with cells isolated from rabbit intestine and tissue homogenates from liver, kidney, and brain. The enterotoxin was found to bind in a specific and saturable manner to cells from intestine and to tissue homogenates from liver and kidney but not the brain. Detailed studies of the binding were carried out with the ileal epithelial intestinal cells. The rate and amount of binding of enterotoxin to cells appeared to be temperature dependent. Apparent affinity and association and dissociation rate constants were calculated for what appeared to be two classes of saturable binding sites. The amount of enterotoxin molecules that bound per milligram of cell protein was similar in tissue of intestinal, liver, and kidney origin (approximately 10(13) molecules/mg of cell protein). Spontaneous dissociation into the supernatant medium was observed to be much slower than expected from calculations based on the rate of association. Chaotropic ions did not enhance dissociation of the enterotoxin from cells. Enterotoxin binding was demonstrated to be heat labile (binding ability was lost after the enterotoxin was heated for 10 min at 60 degrees C). A mechanism is described whereby the enterotoxin binds and then is inserted into the membrane where it becomes trapped.
journal_name
Biochemistryjournal_title
Biochemistryauthors
McDonel JLdoi
10.1021/bi00562a014subject
Has Abstractpub_date
1980-10-14 00:00:00pages
4801-7issue
21eissn
0006-2960issn
1520-4995journal_volume
19pub_type
杂志文章相关文献
BIOCHEMISTRY文献大全abstract::The activation of adenosine-5'-monophosphate aminohydrolase from rabbit skeletal muscle by H+ has been demonstrated. Evidence is presented which indicates that the binding of H+ and K+ is linked, in that the dissociation constant (KA) for K+ activation is reduced as the pH is lowered. Concomitantly, the pK of several ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00641a013
更新日期:1977-11-01 00:00:00
abstract::Myelin basic protein (MBP) binds to negatively charged lipids on the cytosolic surface of oligodendrocyte membranes and is most likely responsible for adhesion of these surfaces in the multilayered myelin sheath. It can also polymerize actin, bundle F-actin filaments, and bind actin filaments to lipid bilayers through...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0519194
更新日期:2006-01-17 00:00:00
abstract::High-precision studies of oxygen binding in hemoglobin (HbA0) solutions at near-physiological concentrations (2-12 mM heme; pHs 7.0-9.1; various buffers) have led to an unanticipated result: an unmeasurably low contribution from the triply ligated species. We have obtained this result from new differential oxygen-bind...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00387a038
更新日期:1987-06-30 00:00:00
abstract::The members of the glutamine amidotransferase (GATase) family catalyze the incorporation of ammonia within numerous metabolic pathways and can be categorized in two classes. Here, we concentrated on class I GATases, which are heteromeric enzyme complexes consisting of synthase subunits and glutaminase subunits with a ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.9b00286
更新日期:2019-06-04 00:00:00
abstract::The dynamics of the backbone and (some of) the side chains of lac headpiece (1-56; lac HP56) have been studied for the free protein and for its complex with lac half-operator DNA by 15N T1 and T1p relaxation measurements combined with [1H-15N] NOE experiments. For the structurally well-defined part of the free lac HP5...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi961670d
更新日期:1997-01-07 00:00:00
abstract::The rate of the reaction between p-nitroperoxybenzoic acid and cytochrome c peroxidase (CcP) has been investigated as a function of pH and ionic strength. The pH dependence of the reaction between CcP and peracetic acid has also been determined. The rate of the reactions are influenced by two heme-linked ionizations i...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991497w
更新日期:1999-11-23 00:00:00
abstract::Nitric oxide is produced in mammals by the nitric oxide synthase (NOS) isoforms at a catalytic site comprising a heme associated with a biopterin cofactor. Through genome sequencing, proteins that are highly homologous to the oxygenase domain of NOSs have been identified, in particular in bacteria. The active site is ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/acs.biochem.6b01018
更新日期:2017-02-07 00:00:00
abstract::Despite the expression of only one type of receptor, there is great variation in the ability of different cell types to discriminate between C5a and its more stable metabolite, C5a des Arg74. The mechanism that underlies this phenomenon is not understood but presumably involves differences in the interaction with the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi990139q
更新日期:1999-07-27 00:00:00
abstract::The dietary flavonoid quercetin has a broad range of biological activities, including potent antitumor activity against several types of tumors. Recently, it has been shown that quercetin inhibits cancer cells proliferation by depleting cellular microtubules and perturbing cellular microtubule functions. However, the ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi025952r
更新日期:2002-10-29 00:00:00
abstract::The natural product hypericin is a photosensitive polycyclic aromatic dione compound, which has been widely investigated because of its virucidal and antitumor properties. Although it has been suggested that singlet oxygen or a radical species might be responsible for its biological action, its mechanism of action rem...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991147+
更新日期:1999-08-31 00:00:00
abstract::The molecular structure of ammonium deoxycytidylyl-(3'-5')-deoxyguanosine, crystallized from aqueous acetone near pH 4, was determined for X-ray diffraction data. The crystals were tetragonal, space group P43212 with a = b = 11.078 (1) A and c = 45.826 (4) A. The structure was solved by tangent expansion of phases bas...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00277a014
更新日期:1983-04-12 00:00:00
abstract::The 14-3-3 proteins interact with diverse cellular molecules involved in various signal transduction pathways controlling cell proliferation, transformation, and apoptosis. To aid our investigation of the biological function of 14-3-3 proteins, we have set out to identify high-affinity antagonists. By screening phage ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi991353h
更新日期:1999-09-21 00:00:00
abstract::There is much debate whether the fatty acid substrate of lipoxygenase binds "carboxylate-end first" or "methyl-end first" in the active site of soybean lipoxygenase-1 (sLO-1). To address this issue, we investigated the sLO-1 mutants Trp500Leu, Trp500Phe, Lys260Leu, and Arg707Leu with steady-state and stopped-flow kine...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0489098
更新日期:2004-10-19 00:00:00
abstract::The binding of various forms of vanadate to myosin and myosin subfragment 1 (S-1) was studied by 51V NMR at increasing vanadate concentrations between 0.06 and 1.0 mM. The distribution of the various forms of vanadate in the solution depended on the total concentration of vanadate. At low concentrations, the predomina...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00490a029
更新日期:1990-09-25 00:00:00
abstract::Rhodopsin kinase phosphorylates serine- and threonine-containing peptides from bovine rhodopsin's carboxyl-terminal sequence. Km's for the peptides decrease as the length of the peptide is increased over the range 12-31 amino acids, reaching 1.7 mM for peptide 318-348 from the rhodopsin sequence. The Km for phosphoryl...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00448a013
更新日期:1989-10-31 00:00:00
abstract::PsbU is a lumenal peripheral protein in the photosystem II (PS II) complex of cyanobacteria and red algae. It is thought that PsbU is replaced functionally by PsbP or PsbQ in plant chloroplasts. After the discovery of PsbP and PsbQ homologues in cyanobacterial PS II [Thornton et al. (2004) Plant Cell 16, 2164-2175], w...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi047539k
更新日期:2005-09-13 00:00:00
abstract::Inosine 5'-monophosphate (IMP) cyclohydrolase catalyzes the cyclization of 5-formaminoimidazole-4-carboxamide ribonucleotide (FAICAR) to IMP in the final step of de novo purine biosynthesis. Two major types of this enzyme have been discovered to date: PurH in Bacteria and Eukarya and PurO in Archaea. The structure of ...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi061637j
更新日期:2007-05-01 00:00:00
abstract::The structure of the His-94-->Cys variant of human carbonic anhydrase II (CAII) has been determined by X-ray crystallographic methods to a resolution of 2.3 A with a final crystallographic R factor of 0.155. This variant of CAII crystallizes in orthorhombic space group P2(1)2(1)2(1) which is the first example of a new...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00057a015
更新日期:1993-02-16 00:00:00
abstract::Pyruvate decarboxylase (PDC) uses thiamine diphosphate as an essential cofactor to catalyze the formation of acetaldehyde on the pathway of ethanol synthesis. Here we report the crystallographic image of a prereaction intermediate of a bacterial pyruvate decarboxylase prepared by cocrystallizing the enzyme with pyruva...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi901864j
更新日期:2010-03-02 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::Polyhydroxybutyrate (PHB) synthases catalyze the conversion of beta-hydroxybutyryl coenzyme A (HBCoA) to PHB. These enzymes require an active site cysteine nucleophile for covalent catalysis. A protein BLASTp search using the Class III Chromatium vinosum synthase sequence reveals high homology to prokaryotic lipases w...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9928086
更新日期:2000-04-11 00:00:00
abstract::Positively charged cyclic hexapeptide Phe-Arg-Cys-Arg-Cys-Phe-CONH2 (FRCRCFa) represents a group of conformationally constrained peptides that block the cardiac sarcolemma Na(+)-Ca2+ exchanger [Khananshvili et al. (1995b) J. Biol. Chem. 270, 16182-16188]. Here, we study the kinetic mechanisms of FRCRCFa-induced inhibi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi961099i
更新日期:1996-12-10 00:00:00
abstract::The active form of the animal fatty acid synthase (FAS) is a dimer of identical multifunctional polypeptides, each containing seven discrete functional domains, that cooperate to form two centers for palmitate synthesis. To assess the importance of domain cooperation across the subunit interface in the reaction mechan...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi971886v
更新日期:1998-02-24 00:00:00
abstract::Pancreatic and duodenal homeobox 1 (Pdx1) is a homeodomain transcription factor belonging to the ParaHox family. Pdx1 plays an essential role in pancreatic endocrine and exocrine cell development and maintenance of adult islet beta-cell function. Mutations in the human pdx1 gene are linked to an early onset form of no...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi060969l
更新日期:2007-03-20 00:00:00
abstract::Polymerase eta is a member of the Y family of DNA polymerases which is able to bypass thymine dimers efficiently and in a relatively error-free manner. To elucidate the mechanism of dimer bypass, the efficiency of dAMP and pyrene nucleotide insertion opposite the thymine dimer and its N3-methyl derivatives was determi...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0345687
更新日期:2003-08-12 00:00:00
abstract::Nicotinic acetylcholine receptors (nAChRs) were studied in detail in the past regarding their interaction with therapeutic and drug addiction related compounds. Using fast kinetic whole-cell recording, we have now studied effects of tacrine, an agent used clinically to treat Alzheimer's disease, on currents elicited b...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi101789y
更新日期:2011-03-22 00:00:00
abstract::Detailed 31P NMR measurements have been conducted on pig platelet dense granules and aqueous mixtures of ATP, ADP, MgCl2, and 5HT. The resonance line widths of the dense granule nucleotides were temperature independent above approximately 30 degrees C; below this temperature they exhibit a strong temperature dependenc...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00298a004
更新日期:1984-01-31 00:00:00
abstract::Polyamides composed of N-methylpyrrole (Py) and N-methylimidazole (Im) subunits can bind in the minor groove of DNA at predetermined sequences with subnanomolar affinity and high specificity. Covalent linkage of polymer subunits using a gamma-aminobutyric acid linker has been shown to increase both the affinity and sp...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi0022339
更新日期:2001-01-09 00:00:00
abstract::Conjugative transfer of F-like plasmids in Escherichia coli is repressed by a plasmid-encoded protein, FinO. FinO blocks the translation of TraJ, a positive activator of transcription of genes required for conjugation. FinO binds a traJ antisense RNA, FinP, thereby protecting it from degradation, and catalyzes FinP-tr...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi9911482
更新日期:1999-10-19 00:00:00
abstract::The quercetin binding sites on spinach chloroplast coupling factor 1 (CF1) have been investigated using direct and competitive binding, stopped-flow, temperature-jump, and fluorescence resonance energy transfer measurements. It was found that 8-anilino-1-naphthalensulfonic acid (ANS) competes with quercetin binding at...
journal_title:Biochemistry
pub_type: 杂志文章
doi:10.1021/bi00646a001
更新日期:1976-01-13 00:00:00