(1) Manometric studies with resting cells obtained by growth on each of these sulfur sources yielded net oxygen uptake for all substrates except sulfite and dithionate.
(2) Typically the iron-iron axis (gz) of the binuclear iron-sulfur clusters is in the membrane plane.
(3) Our study suggests that a major part of the renal antimineralocorticoid activity of spironolactone may be attributable to minor sulfur-containing metabolites or their precursors having a high renal clearance that affords access to their site of activity via the renal tubular fluid.
(4) Ferredoxin reductase (Fd-reductase) supplies reducing equivalents obtained from NADPH to mitochondrial cytochrome P450 enzymes via the small iron-sulfur protein ferredoxin.
(5) The loss of enzyme activity in sulfur-rhodanese does not involve cysteinyl residues but can be correlated with the modification of guanidino groups, notably that of Arg-186, the side chain of which may play a role in substrate binding.
(6) In two patients with extensive marrow necrosis, the diagnosis of marrow necrosis was established by morphologic and radioisotopic studies, and the extent of involvement was accurately assessed by marrow scanning with technetium Tc 99m sulfur colloid while the patients were still alive.
(7) It was presumed that thymohydroquinone is excreted as ethereal sulfuric acid conjugate in man.
(8) Also purple sulfur bacteria lowered BOD levels as demonstrated by the growth of T. floridana in sterilized sewage.
(9) An equivalent maximum growth response of rats fed L-methionine or N-acetyl-L-methionine was obtained when the total dietary sulfur amino acids compromised 0.36-0.41% of the diet.
(10) Histopathological evaluations showed that sulfuric acid particles alone did not cause inflammatory responses in centriacinar units of rat lung parenchyma (expressed in terms of percent lesion area) but did cause significant damage (cell killing followed by a wave of cell replication) in nasal respiratory epithelium, as measured by uptake of tritiated thymidine in the DNA of replicating cells.
(11) Ac-MPS of the hyaluronic acid type prevail in the ground substance of the myxoid and fibroblastic mesenchyma, while the substances containing sulfuric groups predominate in the tissue matrix exhibiting fibrogenic tendencies.
(12) Previous work demonstrated a differential decrease in iron-sulfur centers A, B and X which indicated that center X serves as a branch point for parallel electron flow through centers A and B (Golbeck, J.H.
(13) Our observation leads to the suggestion that, in vivo, either rhodanese is maintained in its more stable sulfur-substituted form or cellular compartmentalization prevents inactivation by nitrite.
(14) In contrast, the (Rp)-isomers, which have an equatorial exocyclic sulfur atom, bound to the enzyme without stimulation of its activity.
(15) A strong shoulder was observed at 2481.7 eV on the low-energy side of the sulfate absorption edge, deriving from a novel type of sulfur having a slightly lower oxidation state than sulfate sulfur.
(16) Long-term treatment with furosemide (up to 13 months) caused transient changes in the elemental content of the pancreatic acinar cells: a decrease in chloride and sulfur, and an increase in phosphorus, potassium and magnesium.
(17) The iron-sulfur proteins of the green photosynthetic bacterium Chlorobium have been characterized by oxidation-reduction potentiometry in conjunction with low-temperature electron paramagnetic resonance spectroscopy.
(18) The reaction is based on the reduction of sulfur dioxide at a dropping mercury electrode.
(19) Proton induced X-ray emission (PIXE) analyses were performed on single hair fibers in triplicate from 103 individuals in order to determine sulfur, zinc, calcium, and chlorine content.
(20) In a survey of the proteins from human hair, a genetic electrophoretic variant has been observed in the high-sulfur protein region.
Sulphonium
Definition:
(n.) A hypothetical radical, SH3, regarded as the type and nucleus of the sulphines.
Example Sentences:
(1) Examination of other potential inhibitors revealed a rank order of potency against calpain to be: peptidyl sulphonium methyl ketones > fluoromethyl ketones, diazomethyl ketones >> acyloxymethyl ketones, an order which differs sharply from that found for cathespin B.
(2) In addition, thermolytic cleavage of the high-pH enzyme results in fragmentation of the polypeptide chain in a fashion analogous to model reactions of phenacylmethionyl dipeptides and other methionine-192 sulphonium salts.
(3) These experiments also suggested the possibility that methionine residues in the histones were alkylated to give methylmethionine sulphonium residues.
(4) Carbachol, suberyldicholine and the sulphonium analogue of acetylcholine were all found to be efficacious agonists in the sense that the results indicate that all of them, in sufficiently high concentration, would be able to open 90% or more of channels if it were not for channel block.
(5) The inhibitory effect of 5'-methylthiotubercidin (competitive) and 5'-dimethylthioadenosine sulphonium salt (non-competitive) was also demonstrated.
(6) Antimicrobial properties of some new carbonyl stabilized sulphonium ylides have been tested against two bacteria Staphylococcus aureus, Escherichia coli and two fungi Alternaria alternata and Curvularia lunata.
(7) To this end, DL-cysteine (200 mg 4 times daily) and DL-methionine-methyl sulphonium chloride (MMSC, 500 mg 4 times daily) were administered orally.
(8) Glucose transport was also inhibited by the water-soluble tryptophan-inactivating agent, dimethyl(2-hydroxy-5-nitrobenzyl)sulphonium bromide, and this is consistent with the presence of tryptophan residues in two of the exofacial amino-acid sequences proposed as candidates for involvement in glucose binding sites.
(9) We have synthesized the two naturally occurring enkephalins (Methionine-Enkephalin and Leucine-Enkephalin) as well as four other analogs (Methinonine-Enkephalin amide, S-Benzyl sulphonium analog of Methionine-Enkephalin, 3-Benzyl-tyrosine analog of Methionine-Enkephalin and 3-Benzyl-tyrosine analog of Leucine-Enkephalin) in order to study their relative potency and their inactivation of different tissues.
(10) Ribulose 1,5-bisphosphate carboxylase [3-phospho-D-glyceratecarboxy-lyase (dimerizing), EC 4.1.1.39] is rapidly and irreversibly inactivated by micromolar concentrations of dimethyl (2-hydroxy-5-nitrobenzyl) sulphonium bromide (DMHNB), a tryptophan selective reagent, after reversible protection of the reactive sulphydryl groups.
(11) The reaction of cardiotoxin with iodoacetamide or iodomethane at pH 3.0 afforded the corresponding methionine sulphonium derivatives.
(12) Two biologically active aziridine ring-containing compounds, N,N-ethylene urethane (I) and N,N-ethylene urea (II), have been shown to react with methionine in dilute phosphate buffer (pH 7.4) at 37 degree C. Degradative procedures indicate that the aziridine ring effectively alylates the thio ether group of methionine and other thio ether-containing amino acids to produce sulphonium salts (V).
(13) A stimulating effect of methylethyl(silatrane-I-ilmethyl)-sulphonium iodides, 1-(ethoxy)silatranes and 1-(chloromethyl)silatrane on the processes of rat test acetate ulcer healing is studied.
(14) The enzyme appears to be highly specific: the replacement of the 6'-amino group of the sulphonium compound alone results in a complete loss of activity.
(15) The sulphonium compounds have a 78(-524)-fold higher activity than its nitrogen analogues.
(16) Results conclusively demonstrate that the chemically and physically different modified enzymes prepared at pH 4 and at pH 7 both contain the phenacyl group at methionine-192 in the sulphonium salt form.
(17) To this end, DL-methionine methyl sulphonium chloride (MMSC, 500 mg four times daily) or DL-cysteine (200 mg four times daily) were orally administered with cimetidine.
(18) The biological utilization of DL-methionine (MET), DL-methionine-hydroxy-analog and DL-S-methyl-methionine-sulphonium-chloride (SMM) was tested in rat growth assay.
(19) The free radical scavengers methyl-methionine sulphonium bromide and cysteine (5%) protected the rat gastric mucosa against ischaemic injury produced by reserpine (5 mg kg-1 i.p.).
(20) These results do not support a sulphonium ion intermediate in the formation of the 2-hydroxypropyl-mercapturic acid metabolite of DCP.