Disease relevance of sulfonium

• A cyclic sulfonium compound, S-methyl homocysteine thiolactone (SMHT), is formed from methionine during in vitro tRNA aminoacylation catalyzed by Escherichia coli methionyl-tRNA synthetase [1].
• The presence of sulfonium groups in EDDHSA produces an increase in acidity that affects their protonation and stability constants, although the pFe values suggest that EDDHSA could be also effective to correct iron chlorosis in plants [2].
• Inhibition of Clostridium perfringens phospholipase C by ammonium and sulfonium dications [3].

Psychiatry related information on sulfonium

• These results suggest that the stimulation of locomotor activity by the sulfonium analog is mediated indirectly through the release of DA [4].

High impact information on sulfonium

• An analog of luteinizing hormone-releasing hormone containing a gamma-lactam as a conformational constraint has been prepared with the use of a novel cyclization of a methionine sulfonium salt [5].
• To demonstrate thioether methylation in vivo, mice were injected with [methyl-3H]methionine plus different thioethers, and extracts of lungs, livers, kidneys, and urine were analyzed by high-performance liquid chromatography for the presence of [3H]methyl sulfonium ions [6].
• Similar to when betaine was added to a methionine-deficient diet, choline or sulfonium analogs of betaine induced BHMT expression [7].
• The sulfonium ion linkage in myeloperoxidase. Direct spectroscopic detection by isotopic labeling and effect of mutation [8].
• Chemical modification of antithrombin III, the major plasma protease inhibitor, with the tryptophan reagent dimethy(2-hydroxy-5-nitrobenzyl) sulfonium bromide, results in the incorporation of one hydroxynitrobenzyl moiety per molecule of antithrombin III [9].

Chemical compound and disease context of sulfonium

• However, the sulfonium analog did not stimulate locomotor activity when rats were pretreated with saline instead of nialamide [4].
• Similarly, after intraaccumbens injection, the sulfonium analog also produced a marked stimulation of locomotor activity, and this effect was inhibited by the DA receptor antagonist, haloperidol (0.2 mg/kg, IP) [4].
• In addition, the stimulation of locomotor activity produced by the sulfonium analog in rats pretreated with nialamide was completely inhibited by the DA synthesis inhibitor, alpha-methyl-p-tyrosine [4].
• Similarly, the sulfonium analog produced a marked stimulation of locomotor activity after it was injected into the nucleus accumbens of rats that were previously injected into this region with 6-hydroxydopamine [4].

Biological context of sulfonium

• In the assembly, 1-hydroxyl glucosazido- and 1-thio uronic acid donors are combined in a sequential glycosylation protocol using sulfonium triflate activator systems [10].
• The results of these experiments strongly support a role for Glu47 as an anchor for the sulfonium pole of (S,S)-SAM, and consequently a role as an active site determinant of reaction specificity [11].
• The types of transformations in which it is involved include decarboxylation, electrophilic addition to any of the three carbons bonded to the central sulfur atom, proton removal at carbons adjacent to the sulfonium, and reductive cleavage to generate 5'-deoxyadenosyl 5'-radical intermediates [12].
• In addition, incubation of the Met-192 phenacyl sulfonium enzyme at neutral pH causes a smooth irreversible change to the new phenacyl-enzyme as monitored by changes in enzymatic activity, susceptibility to dealkylation using 2-mercaptoethanol, and ultraviolet difference absorption spectral properties [13].
• Key to success are the formation of its 2,4-disubstituted furan moiety via a palladium-catalyzed alkylation of vinylepoxide 10 derived from sulfonium salt 8 and the use of SEM ethers as the protecting groups for the phenolic OH functions [14].

Anatomical context of sulfonium

• The sulfonium analogue, however, was much more cytotoxic to HL-60 cells than PAF itself, in the concentration range 0-15 microM; replacement of the acetate group by a benzyl group increased the cytotoxicity to the level of that of the methoxy analogue of PAF [15].
• Replacement of mouse LM fibroblast choline by a sulfonium analog. Effects on membrane properties as determined by virus probes [16].

Associations of sulfonium with other chemical compounds

• To duplicate the sulfonium link in myeloperoxidase and to obtain information on its mechanism of formation, we have engineered a methionine residue close to the 2-vinyl group in recombinant pea cytosolic ascorbate peroxidase (rpAPX) by replacement of Ser160 by Met (S160M variant) [17].
• Transferred nuclear Overhauser effect and rotating-frame Overhauser enhancement NMR spectroscopies are used to probe the conformation of a bicyclic sulfonium ion, which is an analogue of the naturally occurring glycosidase inhibitor castanospermine, bound to the enzyme glucoamylase G2 [18].
• The methionyl group typically adopts an extended conformation in complexes with enzymes that transfer the methyl group from the sulfonium center, but is more folded in complexes with proteins that do not catalyze reactions involving the sulfur and which can use the sulfonium sulfur solely as a binding site [19].
• These compounds are 5'-methylethyl(5'adenosyl) sulfonium chloride (MEAS), 5'-methylpropyl-(5'adenosyl)sulfonium chloride (MPAS), and 5'-ethylpropyl(5'-adenosyl)sulfonium chloride (EPAS) They were prepared by reacting an alkyl iodide with the appropriate alkyladenosyl thioether [20].
• The combined results of these studies have been initially interpreted in terms of a neutral pH, phenacyl bromide modification resulting in formation of a new modified enzyme via the Met-192 sulfonium salt [13].

Gene context of sulfonium

• Sequence comparisons suggest that the two ester linkages to the heme may also occur in other homologous mammalian peroxidases, but that the sulfonium ion linkage may be a unique feature of myeloperoxidase [21].
• Synthetic decarboxylated S-adenosyl-L-methionine (dcAdoMet), a mixture of the absolute configuration of S and R at the sulfonium center, was evaluated as a substrate for the measurement of spermidine synthase activity [22].
• Methylation of glucagon, characterization of the sulfonium derivative, and regeneration of the native covalent structure [23].
• Treatment of c[alphaZ-Lys-Pro-Aba-(6-CH2-OC6H5)-Glyn], obtained by peptide synthesis in solution, with R2S/TFA simutaneously cleaved the Z protecting group and the phenyl ether function and led to a series of cyclopeptide sulfonium salts [24].
• The structural features of S-adenosyl-L-methionine (SAM)3 required for optimal binding to a nucleolar 2'-O-methyltransferase were elucidated using various analogs of SAM with modifications of the amino acid, sugar, sulfonium center, and base portions of the molecule [25].

Analytical, diagnostic and therapeutic context of sulfonium

• The Met243 sulfonium ion linkage is responsible for the anomalous magnetic circular dichroism and optical spectral properties of myeloperoxidase [26].
• The biliary excretion of cyclic sulfonium conjugates was quantitated indirectly by measuring the release of tetrahydrothiophene (THT) after treatment of the bile with base [27].
• Capillary electrophoresis was used for monitoring the stability of S-adenosylmethionine in aqueous solution under different conditions of storage and incubation used for "in vitro" and "in vivo" experiments, by evaluating both the entity of degradation and the possibility of epimerization at the sulfonium group [28].
• Efficient clustering of cyclic sulfonium salts applying liquid secondary ion mass spectrometry [29].
• It is also reported the characterization of new sulfonium compounds by U.V. spectrophotometry, thin layer chromatography, high voltage electrophoresis, hydrolysis to known fragments [30].

References