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Research has been conducted on dimethyl sulfoxide reductase from Rhodobacter capsulatus. The construction of the system used for expression site-directed mutants of this reductase in the natural host in order to generate and express dimethyl sulfoxide reductase with Y114F mutantion is described.

Research has been conducted on the ruthenium(II)- and ruthenium(III)-chloride-dimethyl sulfoxide precursors and the antimetasatic drug [ImH][trans-RuCl (sub)4 (dmso-S)] (Im= imidazole, dmso= dimethyl sulfoxide). The reactivity of these compounds toward nitric oxide has been studied and the details are reported.

Research has been conducted on the metal phosphates' layered structures. The method for the ZrPO (sub)4 Cldmso (dimethyl sulfoxide) preparation via direct precipitation has been developed and is described.

Research has been conducted on the dimethyl sulfoxide solvated thallium(III) ion. The vibrational spectra and the structure of this ion have been investigated in the dimethyl sulfoxide solution and in a solid state, and the results of the comparison of the coordination and bonding of solvated thallium(III) ions with those of the other solvated metal ions with the d (super)10 electronic configuration are presented.

Research has been conducted on dimethyl sulfoxide. The characterization of the binary mixtures of this compound with different cosolvents has been carried out via suitable probe and homomorph couples, and the description of various dimethyl sulfoxide and water mixtures is presented.

Analysis of Escherichia coli dimethyl sulfoxide reductase by protein film votammetry shows that the catalytic activity of the enzyme is confined to a narrow window of electrode potential as determined by oxidation-reduction reactions. Implications of this finding in the molybdenum-enzyme catalytic reactions of the enzyme are discussed.

X-ray crystallographic and spectrophotometric studies of the dimethyl sulfoxide reductase show that aerobic exposure of the enzyme, in Hepes buffer, causes dissociation of a pair of thiolates resulting in the loss of catalytic activity. Data further indicate that the dissociation reaction can be reversed by a redox-cycling process.

Research has been conducted on the 4-nitrophenyl X-substituted benzoates. The reaction of these benzoates with alicyclic secondary amines in H (sub)2 O containing dimethyl sulfoxide has been carried out and the results are presented.

Successful improvement of cryopreservation protocols for cells in suspension requires knowledge of how such cells respond to the biophysical stresses of freezing (intracellular ice formation, water transport) while in the presence of a cryoprotective agent (CPA). This work investigates the biophysical water transport response in a clinically important cell type - isolated hepatocytes - during freezing in the presence of dimethylsulfoxide (DMSO). Sprague-Dawley rat liver hepatocytes were frozen in Williams E media supplemented with 0, 1, and 2 M DMSO, at rates of 5, 10, and 50 [degrees] C/min. The water transport was measured by cell volumetric changes as assessed by cryomicroscopy and image analysis. Assuming that water is the only species transported under these conditions, a water transport model of the form dV/dT = f([L.sub.pg]([CPA]), [E.sub.Lp]([CPA]), T(t)) was curve-fit to the experimental data to obtain the biophysical parameters of water transport - the reference hydraulic permeability ([L.sub.pg]) and activation energy of water transport ([E.sub.Lp]) - for each DMSO concentration. These parameters were estimated two ways: (1) by curve-fitting the model to the average volume of the pooled cell data, and (2) by curve-fitting individual cell volume data and averaging the resulting parameters. The experimental data showed that less dehydration occurs during freezing at a given rate in the presence of DMSO at temperatures between 0 and -10[degrees]C. However, dehydration was able to continue at lower temperatures (< - 10[degrees]C) in the presence of DMSO. The values of [L.sub.pg] and [E.sub.Lp] obtained using the individual cell volume data both decreased from their non-CPA values - 4.33 x [10.sup.-13] [m.sup.3]/N-s (2.69 [Mu]m/min-atm) and 317 kJ/mol (75.9 kcal/mol), respectively - to 0.873 x [10.sup.-13] [m.sup.3]/N-s (0.542 [Mu]m/min-atm) and 137 kJ/mol (32.8 kcal/mol), respectively, in 1 M DMSO and 0.715 X [10.sup.-13] [m.sup.3]/N-s (0.444 [Mu]m/min-atm) and 107 kJ/mol (25.7 kcal/mol), respectively, in 2 M DMSO. The trends in the pooled volume values for [L.sub.pg] and [E.sub.Lp] were very similar, but the overall fit was considered worse than for the individual volume parameters. A unique way of presenting the curve-fitting results supports a clear trend of reduction of both biophysical parameters in the presence of DMSO, and no clear trend in cooling rate dependence of the biophysical parameters. In addition, these results suggest that close proximity of the experimental cell volume data to the equilibrium volume curve may significantly reduce the efficiency of the curve-fitting process.

The mechanism behind the regulation of dimethyl sulfoxide (DMSO) reductase genes of the phototroph Rhodobacter sphaeroides by both DMSO and oxygen was studied by investigating the transcriptional regulation of the dorC, dorR and dorS promoters. The dorC::lacZ expression was minimized by up to one-third when the cells were grown photosynthetically with DMSO and with medium to high lighting. The induction also depends on the DorR and DorS proteins.

The kinetics of dimethyl sulfoxide reduction was analyzed in Rhodovulum euryhalinum strain DSM 4868 during dimethyl sulphoxide (DMSO) reduction with reduced sulfur compounds. Characterization of DMSO reduction with sulphide by Rhodovolum euryhalum indicated a sulphide oxidation rate of 60 minutes which led to the formation and subsequent transformation of elemental sulfur to sulphate. Furthermore, reduction of sulphide and sulfates served as electron donors during the reduction of DMSO to dimethyl sulphide.

The effect of dimethyl sulfoxide (DMSO) in neutrophil recruitment in the airways was investigated in dog airways in vivo. Interleukin (IL)-8 production in human airway epithelial cells after exposure to Pseudomonas aeruginosa (PA) supernatant was shown to increase in a dose-dependent manner. This increase, however, was inhibited by DMSO. Incubation of a bypassed segment of dog trachea in the PA supernatant, followed by DMSO treatment, caused a marked decrease in IL-8 concentration. This suggests that DMSO inhibits IL-8 recruitment in the airways.

This study determined if reported decreases in the Delta subunit of ATP synthase and nuclear-encoded cytochrome c oxidase subunits in hearts of copper-deficient rats were secondary to the heart disease pathology or due to lack of the trace element. Male weanling Long-Evans rats were randomly divided into six groups: rats fed a copper-adequate or copper-deficient diet (with free access) with or without 5% dimethyl sulfoxide (DMSO) in the drinking water and rats pair-fed the copper-adequate or copper-deficient diet without DMSO treatment. After 4 wk, rats in the groups fed the copper-deficient diet had lower liver superoxide dismutase and heart cytochrome c oxidase activities compared with groups fed the copper-adequate diet. Administration of DMSO, an antioxidant, and energy restriction (pair-feeding) partially blocked cardiac hypertrophy in rats fed the copper-deficient diet. Greater mitochondrial volume density and mitochondrial:myofibrillar ratio and disrupted myofibrils and basal laminae were observed in the hearts from rats fed the copper-deficient diet and not treated with DMSO compared with hearts from groups fed the copper-adequate diet. The DMSO-treated rats fed the copper-deficient diet had hearts with intact structure but enlarged mitochondria compared with other groups fed the copper-deficient diet. The Delta subunit of ATP synthase and the nuclear-encoded cytochrome c oxidase subunits IV and V were depressed in rats fed a copper-deficient diet regardless of antioxidant treatment and pair-feeding. These data suggest that the effects of copper deficiency upon ATP synthase and cytochrome c oxidase proteins are not due to the cardiac pathology.

The effects of dimethyl sulfoxide (DMSO) on the Escherichia coli F1-ATPase were reported. It was shown that DMSO markedly inhibits multisite catalysis in E. coli F1-ATPase. The results suggest that there is a significant difference between the conformation for ADP binding as opposed to ATP binding, and that the ADP-binding conformation is more hydrophilic. E. coli F1 does not display significant Pi binding either in aqueous buffer or in 40 percent DMSO. Moreover, it was inferred that the deltaG for ATP hydrolysis in 40 percent DMSOis between -9.2 and -16.8 kJ/mol.

An X-ray absorption spectroscopic analysis of the molybdenum active site of Escherichia coli dimethyl sulfoxide (DMSO) reductase contained within its native membranes is reported. The bond lengths determined for Escherichia coli DMSO reductase are very similar to those determined for the well-characterized Rhodobacter sphaeroides DMSO reductase, suggesting similar active site structures for the two enzymes.

Research has been conducted on the structural disorder of the dimethyl sulfoxide reductase's active site. The chemical significance of this structural diversity with respect to the geometric relationship between the terminal oxo and serinato oxygen donors has been investigated.