scholarly journals THE EFFECT OF SODIUM DODECYL SULPHATE ON THE FORCED HYDROLYSIS OF FeCl3 SOLUTIONS

2017 ◽  
Vol 38 (1) ◽  
pp. 57
Author(s):  
Mira Ristić ◽  
Jasenka Štajdohar ◽  
Ivana Opačak ◽  
Svetozar Musić
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Intermediate Phase ◽  
Sodium Dodecyl ◽  
Degree Of Crystallinity ◽  
Precipitation Process ◽  
Preferential Adsorption ◽  
Oxide Phases ◽  
Forced Hydrolysis ◽  
The Stability ◽  
Hydrolysis Of

Precipitations by the forced hydrolysis of 0.2 M FeCl3 aqueous solutions between 2 and 72 hours in the presence of 1% sodium dodecyl sulphate (SDS) were investigated. In the absence of SDS a direct phase transformation ß-FeOOH → α-Fe2O3 via dissolution/recrystallization occured in the precipitation system. In the presence of SDS, α-FeOOH as an intermediate phase precipitated and, with a prolonged time of forced hydrolysis, also transformed to α-Fe2O3 via the dissolution/recrystallization mechanism. On the basis of Mössbauer spectra it was concluded that in the presence of SDS, α-Fe2O3 phase possessed a lower degree of crystallinity. In this precipitation process the competition between the stability of Fe(III)-dodecyl sulphate, on one side, and the formation of iron oxide phases, on the other, also played an important role. FE SEM revealed that the big α-Fe2O3 particles possessed the substructure. The elongation of primary α-Fe2O3 particles produced in the presence of SDS was noticed. This effect can be assigned to the preferential adsorption of dodecyl sulphate groups on nuclei and crystallites of FeOOH and α-Fe2O3 phase during the forced hydrolysis of FeCl3 solutions.

scholarly journals Monitoring of the Forced Hydrolysis of FeCl3 Solutions in the Presence of Sodium Dodecyl Sulphate

2018 ◽  
Vol 91 (3) ◽  
Author(s):  
Mira Ristić ◽  
Jasenka Štajdohar ◽  
Ivana Mitar ◽  
Svetozar Musić
Keyword(s):  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Forced Hydrolysis ◽  
Hydrolysis Of

scholarly journals p-NN′-phenylenebismaleimide, a specific cross-linking agent for F-actin

1978 ◽  
Vol 175 (3) ◽  
pp. 1023-1032 ◽  
Author(s):  
P Knight ◽  
G Offer
Keyword(s):  
Quantitative Analysis ◽  
Sodium Dodecyl Sulphate ◽  
Actin Filaments ◽  
Sodium Dodecyl ◽  
Cysteine Residue ◽  
Cross Linking ◽  
Maximum Value ◽  
Cross Links ◽  
The Cross ◽  
Hydrolysis Of

Covalent cross-links can be inserted between the subunits of F-actin by using p-NN′-phenylenebismaleimide. Cross-linking reaches its maximum value when one molecule of reagent has reacted with each actin subunit. p-NN′-Phenylenebismaleimide reacts initially with a cysteine residue on one subunit, the slower cross-linking reaction involving a lysine residue on a neighbouring subunit. Hydrolysis of the actin-bound reagent limits the extent of cross-linking. Quantitative analysis of the amounts of cross-linked oligomers seen on polyacrylamide gels containing sodium dodecyl sulphate suggests that neither the binding of the reagent to actin nor the formation of cross-links introduces strain into the structure. The cross-links do not join together different F-actin filaments, and evidence is presented that suggests that the cross-links join subunits of the same long-pitched helix.

scholarly journals The action of progesterone and diethylstilboestrol on the dehydrogenase and esterase activities of a purified aldehyde dehydrogenase from rabbit liver

1977 ◽  
Vol 161 (1) ◽  
pp. 123-130 ◽  
Author(s):  
R J S Julian
Keyword(s):  
Aldehyde Dehydrogenase ◽  
Sodium Dodecyl Sulphate ◽  
Sodium Dodecyl ◽  
Rabbit Liver ◽  
Polyacrylamide Gels ◽  
Catalytically Active ◽  
Steroid Sensitive ◽  
Hydrolysis Of Esters ◽  
Hydrolysis Of ◽  
Esterase Activities

A steroid-sensitive aldehyde dehydrogenase (EC 1.2.1.3) was purified from rabbit liver and is homogeneous by the criterion of electrophoresis in polyacrylamide gels with or without sodium dodecyl sulphate. The enzyme is tetrameric, of subunit mo.wt. 48 300, and contains no tightly bound zinc. The fluorescence of the protein is decreased in the presence of progesterone, which is inhibitory to the reactions catalysed by the enzyme. When NADH is bound to the enzyme, the fluorescence of the coenzyme is augmented to an extent independent of the presence of steroids or acetaldehyde. The purified enzyme catalyses the oxidation of acetaldehyde and glucuronolactone, and the hydrolysis of 4-nitrophenyl acetate. Each of these reactions is inhibited by progesterone in such a manner as to suggest the formation of a catalytically active enzyme-hormone complex. Diethylstilboestrol inhibits the hydrolysis of esters by this enzyme, but stimulates the oxidation of aldehydes, except at low aldehyde concentrations; the ligand is then inhibitory. NADH inhibits the hydrolysis of 4-nitrophenyl acetate by the enzyme in a partially competitive fashion.

Irreversible heat denaturation of bovine α-lactalbumin

1986 ◽  
Vol 53 (2) ◽  
pp. 249-258 ◽  
Author(s):  
Lesley C. Chaplin ◽  
Richard L. J. Lyster
Keyword(s):  
Molecular Weight ◽  
Sodium Dodecyl Sulphate ◽  
Gel Electrophoresis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Heat Denaturation ◽  
Two Dimensional ◽  
Native Protein ◽  
Denatured Protein ◽  
Hydrolysis Of

SUMMARYThe irreversible heat denaturation of α-lactalbumin (α-la) in 0·1 M-phosphate, pH 7·0, at 100 °C was studied using polyacrylamide-gel electrophoresis (PAGE). PAGE revealed two groups of bands, one moving faster than native α-la and one slower, in addition to some denatured protein which remained at the origin and some residual native α-la. The faster group had unchanged molecular weight, but an increase in charge, partly due to hydrolysis of glutamine and asparagine residues. The slower group was shown by two-dimensional sodium dodecyl sulphate-PAGE to be oligomers of denatured α-la; formation of the smaller oligomers preceded the larger ones. The oligomers reverted to monomers in the presence of dithiothreitol, showing that they were disulphide-linked aggregates of denatured α-la. Immuno-blots of the gels showed that both fast and slow groups of bands had irreversibly lost most of the antigenicity of the native protein.

scholarly journals The active site of penicillinase from Staphylococcus aureus PC1. Isolation of a specific covalent complex with the substrate quinacillin

1975 ◽  
Vol 149 (2) ◽  
pp. 397-401 ◽  
Author(s):  
R Virden ◽  
A F Bristow ◽  
R H Pain
Keyword(s):  
Staphylococcus Aureus ◽  
Sodium Dodecyl Sulphate ◽  
Active Site ◽  
Sodium Dodecyl ◽  
Carboxyl Group ◽  
Guanidinium Chloride ◽  
Group 3 ◽  
Ph Range ◽  
Hydrolysis Of ◽  
Covalent Complex

1. The penicillinase-catalysed hydrolysis of quinacillin was quenched by addition of 5 m-guanidinium chloride or 1% (w/v) sodium dodecyl sulphate, and the quenched reaction mixture was dialysed exhaustively against solutions of the denaturant. 2. Irreversibly bound quinacillin was shown by titration with HgCl2 to be covalently attached to the protein by the β-lactam carboxyl group. 3. The derivative was found to be stable over the pH range 3.5-8.5. 4. Chymotryptic hydrolysis of the product and subsequent fractionation showed that quinacillin was bound to one or possibly two peptides.

scholarly journals Activity and stability of RuO2-coated titanium anodes prepared via the alkoxide route

2006 ◽  
Vol 71 (11) ◽  
pp. 1173-1186 ◽  
Author(s):  
Vladimir Panic ◽  
Aleksandar Dekanski ◽  
Slobodan Milonjic ◽  
Vesna Miskovic-Stankovic ◽  
Branislav Nikolic
Keyword(s):  
Degradation Mechanism ◽  
Sol Gel ◽  
Active Material ◽  
Coating Surface ◽  
Coating Mass ◽  
Voltammetric Behavior ◽  
Forced Hydrolysis ◽  
The Stability ◽  
Hydrolysis Of ◽  
Alkoxide Route

Titanium anodes with an active RuO2 coating of two different thicknesses were prepared from the oxide suspended in ethanol ("ink" method), while the oxide itself was synthesized by the hydrolysis of ruthenium ethoxide in an ethanolic solution (alkoxide route). The morphology of prepared oxide was examined by scanning electron microscopy. The electrochemical properties of the prepared Ti/RuO2 anodes, involving their cyclic voltammetric behavior in H2SO4 and NaCl solutions, activity in the chlorine and oxygen evolution reaction, impedance behavior in H2SO4, and stability during electrolysis in dilute chloride solutions, were investigated. The performances of the anodes are compared to those of a Ti/RuO2 anode prepared by the sol-gel procedure from an oxide sol obtained by the forced hydrolysis of ruthenium chloride in acid solution. The anodes prepared via the alkoxide route showed a higher capacitance and activity for the chlorine evolution reaction than the anode prepared by the inorganic sol-gel procedure. The results of the stability test showed that the utilization of the coating active material is better when the anodes were prepared via the alkoxide route than via the inorganic sol-gel procedure, particularly for anodes with a smaller mass of coating. The different rates of loss of activity indicate a degradation mechanism for the anodes prepared via the alkoxide route in which electrochemical dissolution of RuO2 from the coating surface prevails over the growth of an insulating TiO2 layer in the coating/Ti substrate interphase. The effect of RuO2 dissolution from the coating surface increases with increasing coating mass.

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