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Biochimica Et Biophysica Acta May 1983Guinea pig skin was found to display a high lipoxygenase activity, evidenced by the formation of a hydroxyeicosatetraenoic acid (HETE) from exogenous [14C]arachidonic...
Guinea pig skin was found to display a high lipoxygenase activity, evidenced by the formation of a hydroxyeicosatetraenoic acid (HETE) from exogenous [14C]arachidonic acid. The lipoxygenase activity was localized to the epidermal layer of the skin, was completely inhibited by eicosatetraynoic acid (ETYA) and slightly enhanced by indomethacin. Susceptibility to inactivation by sulfhydryl-directed reagents indicated that an essential sulfhydryl is present in a hydrophobic region of the molecule. The enzyme exhibited a broad pH activity optimum and a Km of 2.48 . 10(-5) M. The cytosolic enzyme has been partly purified by ammonium sulfate precipitation and two steps of of column chromatography and exhibited an apparent high molecular weight. The lipoxygenase and hydroperoxidase activities were resolvable from one another. The physiological and pathophysiological roles of the enzyme remain to be elucidated.
Topics: Animals; Arachidonate Lipoxygenases; Female; Guinea Pigs; Hydrogen-Ion Concentration; Kinetics; Lipoxygenase; Lipoxygenase Inhibitors; Male; Skin; Specimen Handling; Subcellular Fractions; Sulfhydryl Reagents
PubMed: 6405794
DOI: 10.1016/0005-2760(83)90295-3 -
The Journal of Biological Chemistry Feb 1954
Topics: Adenosine Diphosphate; Brain; Hexokinase; Nucleotides; Phosphotransferases; Sulfhydryl Compounds; Sulfhydryl Reagents
PubMed: 13143054
DOI: No ID Found -
The Journal of General Physiology Nov 1948Oxidizing agents of sulfhydryl groups such as iodosobenzoate, alkylating agents such as iodoacetamide, and mercaptide-forming agents such as cadmium chloride, mercuric...
Oxidizing agents of sulfhydryl groups such as iodosobenzoate, alkylating agents such as iodoacetamide, and mercaptide-forming agents such as cadmium chloride, mercuric chloride, p-chloromercuribenzoate, sodium arsenite, and p-carboxyphenylarsine oxide, added in small concentrations to a suspension of sea urchin sperm produced an increase in respiration. When the concentration was increased there was an inhibition. These effects are explained by postulating the presence in the cells of two kinds of sulfhydryl groups: soluble sulfhydryl groups, which regulate cellular respiration, and fixed sulfhydryl groups, present in the protein moiety of enzymes. Small concentrations of sulfhydryl reagents combine only with the first, thus producing an increase in respiration; when the concentration is increased, the fixed sulfhydryl groups are also attacked and inhibition of respiration is the consequence. Other inhibitors of cell respiration, such as cyanide and urethanes, which do not combine with -SH groups, did not stimulate respiration in small concentration.
Topics: Animals; Cell Respiration; Male; Proteins; Respiration; Sea Urchins; Spermatozoa; Sulfhydryl Compounds; Sulfhydryl Reagents; Tissues
PubMed: 18891144
DOI: 10.1085/jgp.32.2.179 -
Kidney International Mar 1989Organomercurial diuretics stimulate renin secretion although the underlying cellular mechanisms remain undefined. Since organomercurials are also known to react with...
Organomercurial diuretics stimulate renin secretion although the underlying cellular mechanisms remain undefined. Since organomercurials are also known to react with sulfhydryl groups, the present studies determined the effects of sulfhydryl reagents on renin secretion. The effects of the non-diuretic mercurial agent, parachloromercuriphenyl-sulfonate (PCMPS), as well as that of other sulfhydryl reagents, N-ethylmaleimide (NEM), N-phenylmaleimide (NPM) and monobromotrimethylammoniobimane (qBBR), on renin secretion were determined in rabbit renal cortical slices. All four reagents stimulated renin secretion. NEM, which has a high membrane permeability, stimulated secretion to a relatively small extent and its effects were not apparent for at least one hour. Conversely, PCMPS, which is much less permanent than NEM, produced the largest stimulation and these effects were apparent within one hour. The stimulation of secretion by sulfhydryl reagents was independent of the concentration of Ca2+, Na+, and K+ in the incubation media, suggesting that the stimulation is not secondary to alterations of intracellular ion concentrations. These results raise the possibility of direct involvement of sulfhydryl groups of particular membrane protein(s) of the juxtaglomerular (JG) cells in some steps leading to renin secretion, and raise the possibility that sulfhydryl reactivity might in part account for the stimulatory effects of organomercurial and other diuretics.
Topics: Animals; In Vitro Techniques; Kidney Cortex; Rabbits; Renin; Stimulation, Chemical; Sulfhydryl Reagents
PubMed: 2651760
DOI: 10.1038/ki.1989.57 -
Biochimica Et Biophysica Acta Aug 1992Many secondary membrane transport systems contain reactive sulfhydryl groups. In this review the applications of SH reagents for analyzing the role of sulfhydryl groups... (Review)
Review
Many secondary membrane transport systems contain reactive sulfhydryl groups. In this review the applications of SH reagents for analyzing the role of sulfhydryl groups in membrane transport systems will be discussed. First an overview will be given of the more important reagents, that have been used to study SH-groups in membrane transport systems, and examples will be given of transport proteins in which the role of cysteines have been analyzed. An important application of SH-reagents to label transport proteins using various SH-reagents modified with fluorescent- or spin-label moieties will be discussed. Two general models are shown which have been proposed to explain the role of sulfhydryl groups in some membrane transport systems.
Topics: Amino Acid Sequence; Biological Transport; Carrier Proteins; Disulfides; Escherichia coli Proteins; Membrane Proteins; Membrane Transport Proteins; Molecular Sequence Data; Monosaccharide Transport Proteins; Quinones; Sulfhydryl Compounds; Sulfhydryl Reagents; Symporters
PubMed: 1510995
DOI: 10.1016/0304-4157(92)90037-b -
Contributions To Nephrology 1988
Topics: Animals; Calcium; Enzyme Activation; Glutaminase; Kidney; Phosphates; Rats; Sulfhydryl Reagents; Swine
PubMed: 3191705
DOI: 10.1159/000415714 -
Chemico-biological Interactions Sep 2008Previously we used site-directed mutagenesis, in vitro expression, and molecular modeling to investigate the inactivation of an invertebrate acetylcholinesterase,...
Previously we used site-directed mutagenesis, in vitro expression, and molecular modeling to investigate the inactivation of an invertebrate acetylcholinesterase, cholinesterase 2 from amphioxus, by the sulfhydryl reagents 5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) and N-ethylmaleimide (NEM). We created the mutants C310A, C466A, C310A/C466A and C310A/F312I to assess the roles of the two cysteines and a proposal that the increased rate of inactivation previously found in an F312I mutant was due to increased access of sulfhydryl reagents to Cys310. Our results indicated that both of the cysteines could be involved in inactivation by sulfhydryl reagents, but that the cysteine near the acyl pocket was more accessible. We speculated that the inactivation of aphid AChEs by sulfhydryl reagents was due to the presence of a cysteine homologous to Cys310 and proposed that this residue could be a target for a specific insecticide. Here we reconsider this proposal.
Topics: Acetylcholinesterase; Animals; Cholinesterase Inhibitors; Drug Design; Humans; Insecticides; Invertebrates; Sulfhydryl Reagents
PubMed: 18384763
DOI: 10.1016/j.cbi.2008.02.006 -
Biometals : An International Journal on... Oct 2021The effects of both Tl and thiol reagents were studied on the content of the inner membrane free SH-groups, detected with Ellman reagent, and the inner membrane... (Review)
Review
The effects of both Tl and thiol reagents were studied on the content of the inner membrane free SH-groups, detected with Ellman reagent, and the inner membrane potential as well as swelling and respiration of succinate-energized rat liver mitochondria in medium containing TlNO and KNO. These effects resulted in a rise in swelling and a decrease in the content, the potential, and mitochondrial respiration in 3 and 2,4-dinitrophenol-uncoupled states. A maximal effect was seen when phenylarsine oxide reacting with thiol groups recessed into the hydrophobic regions of the membrane. Compared with phenylarsine oxide, the effective concentrations of other reagents were approximately one order of magnitude higher in experiments with mersalyl and 4,4'-diisothiocyanostilbene-2,2'-disulfonate, and two orders of magnitude higher in experiments with tert-butyl hydroperoxide and diamide. The above effects of Tl and the thiol reagents became even more pronounced with calcium overload of mitochondria. However, the effects were suppressed by inhibitors of the mitochondrial permeability transition pore (cyclosporine A, ADP, and n-ethylmaleimide). These findings suggest that opening of the pore induced by Tl in the inner membrane can be dependent on the conformation state of the adenine nucleotide translocase, which depends on the activity of its thiol groups.
Topics: Animals; Calcium; Membrane Potential, Mitochondrial; Mitochondria; Mitochondria, Liver; Mitochondrial Membrane Transport Proteins; Permeability; Rats; Rats, Wistar; Respiration; Succinic Acid; Sulfhydryl Compounds; Sulfhydryl Reagents; Thallium
PubMed: 34236558
DOI: 10.1007/s10534-021-00329-6 -
Current Topics in Cellular Regulation 1979
Review
Topics: Allosteric Regulation; Binding Sites; Cold Temperature; Kinetics; Ligands; Muscles; Phosphofructokinase-1; Plants; Prokaryotic Cells; Protein Conformation; Structure-Activity Relationship; Sulfhydryl Reagents
PubMed: 160863
DOI: No ID Found -
Life Sciences. Pt. 2: Biochemistry,... Jul 1971
Topics: Carbon Isotopes; Catechol Oxidase; Chloromercuribenzoates; Chromatography, Thin Layer; Estradiol; Ethylmaleimide; Models, Chemical; NAD; Sulfhydryl Compounds; Sulfhydryl Reagents
PubMed: 4327695
DOI: 10.1016/0024-3205(71)90002-6