scholarly journals Purification and properties of the S1 secondary alkylsulphohydrolase of the detergent-degrading micro-organism, Pseudomonas C12B

1978 ◽  
Vol 169 (3) ◽  
pp. 659-667 ◽  
Author(s):  
Barbara Bartholomew ◽  
Kenneth S. Dodgson ◽  
Stephen D. Gorham
Keyword(s):  
Chain Length ◽  
Alkyl Chain ◽  
Competitive Inhibitor ◽  
Sulphate Group ◽  
Experimental Conditions ◽  
Alkyl Sulphate ◽  
Purification And Properties ◽  
Crude Preparation ◽  
A Chain ◽  
Comamonas Terrigena

The S1 secondary alkylsulphohydrolase of the detergent-degrading micro-organism, Pseudomonas C12B, was separated from other alkylsulphohydrolases and purified to homogeneity. Under the experimental conditions used the enzyme completely hydrolysed d-octan-2-yl sulphate (d-1-methylheptyl sulphate), but showed no activity towards the corresponding l-isomer. Additional evidence has been obtained to indicate that it is probably optically stereospecific for d-secondary alkyl sulphate esters with the ester sulphate group at C-2 and with a chain length of at least seven carbon atoms. Enzyme activity towards racemic samples of heptan-2-yl sulphate (1-methylhexyl sulphate), octan-2-yl sulphate and decan-2-yl sulphate (1-methylnonyl sulphate) increased with increasing chain length. l-Octan-2-yl sulphate is a competitive inhibitor of the enzyme, as are certain primary alkyl sulphates and primary alkanesulphonates. Inhibition by each of the last two types of compounds is characteristic of the behaviour of an homologous series. Inhibition increases with increasing chain length and plots of log Ki values against the number of carbon atoms in each alkyl chain show the expected linear relationship. A crude preparation of the S2 secondary alkylsulphohydrolase was used to show that this particular enzyme hydrolyses l-octan-2-yl sulphate, but is probably inactive towards the corresponding d-isomer. The similarity of the S1 and S2 enzymes to the CS2 and CS1 enzymes respectively of Comamonas terrigena was established, and some comments have been made on the possible roles of these and other alkylsulphohydrolases in the biodegradation of detergents.

scholarly journals Purification, properties and cellular localization of the stereospecific CS2 secondary alkylsulphohydrolase of Comamonas terrigena

1977 ◽  
Vol 167 (3) ◽  
pp. 723-729 ◽  
Author(s):  
G W J Matcham ◽  
K S Dodgson ◽  
J W Fitzgerald
Keyword(s):  
Chain Length ◽  
Cellular Localization ◽  
Indirect Evidence ◽  
Initial Study ◽  
Potassium Salts ◽  
Experimental Conditions ◽  
Alkyl Sulphate ◽  
A Subunit ◽  
A Chain ◽  
Comamonas Terrigena

The availability of homogeneous samples of the potassium salts of L- and D-octan-2-yl sulphate has enabled the separation of the optically stereospecific CS1 and CS2 secondary alkysulphohydrolases from extracts of cells of Comamonas terrigena. The CS2 enzyme was purified to homogeneity, and an initial study was made of its general properties, specificity, cellular localization and relationship to the CS1 enzyme. The CS2 enzyme has a molecular weight of approx. 250000 and a subunit size of approx. 58000, indicating that the molecule is a tetramer. Under the experimental conditions used the enzyme appears to be specific for (+)-secondary alkyl sulphate esters with the sulphate group at C-2 and with a chain length of at least six carbons. Enzyme activity towards racemic C-2 sulphates increases with increasing chain length up to C10, and there is some indirect evidence to suggest that activity declines when that chain length is exceeded. Other indirect evidence confirms that the CS1 enzyme exhibits similar specificity, except that only (-)-isomers can serve as substrates. Both enzymes are present in broth-grown stationary-phase cells of C. terrigena in approximately equal amounts.

scholarly journals Further studies on the substrate specificity and inhibition of the stereospecific CS2 secondary alkylsulphohydrolase of Comamonas terrigena

1980 ◽  
Vol 191 (2) ◽  
pp. 467-473 ◽  
Author(s):  
Carol H. Barrett ◽  
Kenneth S. Dodgson ◽  
Graham F. White
Keyword(s):  
Free Energy ◽  
Chain Length ◽  
Alkyl Chain ◽  
Hydrophobic Interactions ◽  
Standard Free Energy ◽  
Alkyl Chain Length ◽  
Alkyl Sulphate ◽  
Competitive Inhibitors ◽  
Free Energy Of Binding ◽  
Comamonas Terrigena

A series of d-alkan-2-yl sulphate esters (C7–C14) were prepared by sulphation of the resolved parent alcohols by a method that entails complete retention of configuration. These sulphate esters were tested as substrates for the stereospecific CS2 secondary alkylsulphohydrolase of Comamonas terrigena. Vmax. reached a maximum with the C9 compound, whereas logKm decreased linearly as the alkyl-chain length was increased from C7 to C14. A parallel series of l-alkan-2-yl sulphates was also prepared, and these esters, together with homologous series of primary alkyl sulphates and primary alkanesulphonates, were shown to be competitive inhibitors of the CS2 enzyme. For each series of compounds, logKi values decreased linearly with increasing alkyl-chain length. Plots of chain length against the standard free energy of binding (ΔG0) of substrate and inhibitors to the CS2 enzyme showed that the standard free energy of association of a –CH2– group with the enzyme was 2.0–2.4kJ/mol for all classes of compound studied, indicating an important contribution from hydrophobic interactions to the overall binding. Plots for d-alkan-2-yl sulphate substrates and primary alkyl sulphate inhibitors were nearly coincident, suggesting that the overall interaction between a primary ester and the enzyme is the same as that between the isomeric secondary substrate and the enzyme. Plots for l-alkan-2-yl sulphate and alkanesulphonate inhibitors were very similar to each other, but were displaced by 1.5–3.0kJ/mol from that for substrate binding. This indicates that the binding of any one of these particular inhibitors involves one carbon atom fewer than the number involved in binding a substrate of the same chain length. These observations are discussed in terms of a three-point attachment of substrate to the enzyme involving the alkyl chain, sulphate group and the C-1 methyl group.

scholarly journals Purification and properties of the P2 primary alkylsulphohydrolase of the detergent-degrading bacterium pseudomonas C12B

1980 ◽  
Vol 185 (1) ◽  
pp. 23-31 ◽  
Author(s):  
J M Cloves ◽  
K S Dodgson ◽  
G F White ◽  
J W Fitzgerald
Keyword(s):  
Free Energy ◽  
Chain Length ◽  
Alkyl Chain ◽  
Competitive Inhibition ◽  
Deae Cellulose ◽  
Intact Protein ◽  
Alkyl Sulphate ◽  
Degrading Bacterium ◽  
Purification And Properties ◽  
Considerable Length

The P2 primary alkylsulphohydrolase of the soil bacterium Pseudomonas C12B was purified to homogeneity (200-250-fold) by column chromatography on DEAE-cellulose, Sephadex G-100 and butyl-agarose. The intact protein is a dimer with a mol. wt. of 160 000. Activity towards primary alkyl sulphate esters was maximal at pH 8.3, varied little in the range pH 7.8-8.7, but decreased sharply at higher pH. For a homologous series of primary alkyl sulphate substrates (C6-C12), logKm decreased linearly with increasing chain length, corresponding to a contribution to the free energy of association between enzyme and substrate of ‒2.5kJ/mol for each additional CH2 group in the alkyl chain. logKi for the competitive inhibition by secondary alkyl 2-sulphate esters followed a similar pattern (-2.4kJ/mol for each additional CH2 group) except that only n-1 carbon atoms effectively participate in hydrophobic bonding, implying that the C-1 methyl group is not involved. logKi values for inhibition primary alkanesulphonates also depended linearly on chain length but with a diminished gradient, indicating a free-energy increment of ‒1.2kJ/mol per additional CH2 group. The collective results showed the presence of a hydrophobic site on the enzyme capable of accomodating an alkyl chain of considerable length. Cationic structures (in the form of arginine, lysine or histidine), whose presence might be expected for binding the anionic sulphate group, were not detectable at the active site.

Solubility of Cellulose in Binary Mixtures of 1-Alkyl-3-methylimidazolium Acetate and Dimethyl Sulfoxide: Influence of Alkyl Chain Length in the Cation

2019 ◽  
Vol 72 (9) ◽  
pp. 669
Author(s):  
Yuta Tomimatsu ◽  
Yukihiro Yoshimura ◽  
Akio Shimizu
Keyword(s):  
Binary System ◽  
Chain Length ◽  
Mole Fraction ◽  
Binary Systems ◽  
Alkyl Chain ◽  
Alkyl Chain Length ◽  
Anionic Species ◽  
Hydrogen Bond Basicity ◽  
A Chain ◽  
Chain Lengths

The influence of alkyl chain length of cations on cellulose solubility in a neat imidazolium (MIM)-based ionic liquid (IL) [CnMIM][OAc] and [CnMIM][OAc]–DMSO binary system (n=0–6) was investigated. The correlation between cellulose solubility and Kamlet–Taft hydrogen bond basicity (β) was also examined. Cellulose solubility (g per mol IL) in neat [CnMIM][OAc] increased as the cation alkyl chain length decreased from 6 to 2. However, alkyl chain lengths of 1 and 0 resulted in extremely poor cellulose solubility, indicating that a chain length of 2 was optimal for dissolution of cellulose in the system. Cellulose solubility in the [CnMIM][OAc]–DMSO binary system (n=1–6) was greater than that in neat IL, with maximum solubility occurring at an IL mole fraction of ~0.2. Maximum cellulose solubility in the [CnMIM][OAc]–DMSO binary system was slightly better at even alkyl chain lengths (n=2, 4, or 6) than at odd chain lengths (n=1, 3, or 5), with the best solubility at n=4. More interestingly, maximum cellulose solubility and specific IL mole fraction in the IL-DMSO binary system were related with the β values of neat ILs, even with ILs containing different anionic species or cation alkyl chain lengths. This indicates that solubility information in IL-DMSO binary systems is influenced by the characteristics of neat ILs.

Die Kinetik und der Mechanismus der thermischen Reaktion zwischen Schwefeltetrafluorid und Fluor / The Kinetics and the Mechanism of the Thermal Reaction between Sulfurtetrafluoride and Fluorine

1981 ◽  
Vol 36 (11) ◽  
pp. 1381-1385 ◽  
Author(s):  
Alicia Cristina Gonzalez ◽  
Hans Joachim Schumacher
Keyword(s):  
Chain Length ◽  
Total Pressure ◽  
Reaction Rate ◽  
Thermal Reaction ◽  
Primary Process ◽  
Chain Reaction ◽  
Experimental Conditions ◽  
Medium Length ◽  
A Chain ◽  
Kinetics Of

AbstractThe kinetics of the thermal reaction between SF4 and F2 has been investigated between − 2.4 °C and + 24.0 °C, SF6 and very small amounts of S2F10 being the only products. The reaction is a chain reaction of medium length. Total pressure and surface have only insignificant influence. The reaction rate follows the equation: Under the experimental conditions less than 15% of the SF5 radicals are consumed by r (4b). Therefore Oxygen inhibits the reaction eliminating the SF5 radicals, the final products being now SF5O3SF5 and SF6. From the data obtained in the experiments with high oxygen pressures the rate constant of the primary process and the chain length (v) are determined. E = 10.8 ± 0.7 kcal, E1 = 11.9 ± 0.6 kcal and E4 ≃ 0. E2 = 5.0 ± 2.0 kcal (estimated value) and E3 = 4.7 ± 2.5 kcal.

scholarly journals Preparation and characterization of substrates suitable for the study of stereospecific secondary alkylsulphohydrolases of detergent-degrading micro-organisms

1977 ◽  
Vol 167 (3) ◽  
pp. 717-722 ◽  
Author(s):  
G W J Matcham ◽  
K S Dodgson
Keyword(s):  
Alkyl Chain ◽  
Secondary Alcohols ◽  
Sulphate Group ◽  
Initial Information ◽  
Micro Organisms ◽  
Comamonas Terrigena

During the course of the purification of novel stereospecific secondary aklylsulphohydrolases present in certain detergent-degrading micro-organisms, it became apparent that substrates prepared by sulphating secondary alcohols with H2SO4 are heterogeneous. Apart from the racemization that occurs if resolved alcohols are sulphated, evidence is provided to show that other isomers are produced in which the position of the ester sulphate group on the alkyl chain has been altered. These changes can be avoided if pyridine/SO3 reagent (prepared with SO3) is substituted as sulphating agent. Experiments in which secondary alkyl sulphates prepared by both methods were tested as potential substrates for the two secondary alkylsulphohydrolase enzymes of Comamonas terrigena have provided initial information about the specificity of the enzymes.

scholarly journals Silver Nanoparticles Stabilized with Phosphorus-Containing Heterocyclic Surfactants: Synthesis, Physico-Chemical Properties, and Biological Activity Determination

Nanomaterials ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1883
Author(s):  
Martin Pisárčik ◽  
Miloš Lukáč ◽  
Josef Jampílek ◽  
František Bilka ◽  
Andrea Bilková ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Biological Activity ◽  
Zeta Potential ◽  
Chain Length ◽  
Alkyl Chain ◽  
Chemical Properties ◽  
Alkyl Chain Length ◽  
Microbial Pathogens ◽  
Physico Chemical ◽  
Phosphorus Containing

Phosphorus-containing heterocyclic cationic surfactants alkyldimethylphenylphospholium bromides with the alkyl chain length 14 to 18 carbon atoms were used for the stabilization of silver nanodispersions. Zeta potential of silver nanodispersions ranges from +35 to +70 mV, which indicates the formation of stable silver nanoparticles (AgNPs). Long-chain heptadecyl and octadecyl homologs of the surfactants series provided the most intensive stabilizing effect to AgNPs, resulting in high positive zeta potential values and smaller diameter of AgNPs in the range 50–60 nm. A comparison with non-heterocyclic alkyltrimethylphosphonium surfactants of the same alkyl chain length showed better stability and more positive zeta potential values for silver nanodispersions stabilized with heterocyclic phospholium surfactants. Investigations of biological activity of phospholium-capped AgNPs are represented by the studies of antimicrobial activity and cytotoxicity. While cytotoxicity results revealed an increased level of HepG2 cell growth inhibition as compared with the cytotoxicity level of silver-free surfactant solutions, no enhanced antimicrobial action of phospholium-capped AgNPs against microbial pathogens was observed. The comparison of cytotoxicity of AgNPs stabilized with various non-heterocyclic ammonium and phosphonium surfactants shows that AgNPs capped with heterocyclic alkyldimethylphenylphospholium and non-heterocyclic triphenyl-substituted phosphonium surfactants have the highest cytotoxicity among silver nanodispersions stabilized by the series of ammonium and phosphonium surfactants.

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