Lyotropic Behavior of “3,4-(42-Crown-14)benzyl Dodecyl Ether” in Toluene in the Presence of Water

1997 ◽  
Vol 30 (26) ◽  
pp. 8153-8160 ◽  
Author(s):  
Frank A. Brandys ◽  
Coleen Pugh
Keyword(s):  
Dodecyl Ether

scholarly journals Reverse vesicles as a new system for studying enzymes in organic solvents

1992 ◽  
Vol 285 (2) ◽  
pp. 373-376 ◽  
Author(s):  
A Sánchez-Ferrer ◽  
F García-Carmona
Keyword(s):  
Aqueous Solution ◽  
Organic Solvents ◽  
Reverse Micelles ◽  
Active Form ◽  
Ionic Surfactant ◽  
New Approach ◽  
Optically Transparent ◽  
Reverse Vesicles ◽  
Dodecyl Ether ◽  
New System

A new approach to the study of enzyme activity in organic solvents has been developed by using optically transparent reverse vesicles. Polyphenol oxidase was incorporated in an active form into the above ternary system formed by the non-ionic surfactant tetra(ethylene glycol) dodecyl ether/n-dodecane/water. The enzyme in this microenvironment, surprisingly, showed an apparent positive co-operativity which has never before been described either in aqueous solution or in reverse micelles. In addition, the Vmax. expressed was similar to that in water and twice that displayed in reverse micelles.

Characterization of Reaction Center-B875 Complex of Rhodocyclus gelatinosus: QB Site Properties Derived from Reconstitution Experiments

1991 ◽  
Vol 46 (1-2) ◽  
pp. 99-105 ◽  
Author(s):  
I. Agalidis ◽  
E. Rivas ◽  
F. Reiss-Husson
Keyword(s):  
Reaction Center ◽  
Protein Complex ◽  
Electron Acceptors ◽  
Rhodocyclus Gelatinosus ◽  
Pigment Protein Complex ◽  
Ubiquinone Binding ◽  
Dodecyl Ether ◽  
Particle Weight

Abstract Purified reaction center-B875 pigment-protein complex isolated from Rc. gelatinosus (I. Agalidis, E. Rivas, and F. Reiss-Husson, Photosynth. Res. 23, 249 - 255 (1990)) was further characterized. In the chromatophores, the quinone content was shown to be 6 menaquinones 8 and 16 ubiquinones 8 per reaction center, indicating that the pool contained both quinone types. Besides the primary (MK8) and secondary (UQ8 ) electron acceptors of the reaction cen­ter, the complex contains residual quinones from the membrane pool (about 3 MK8 and 5 UQ8) probably associated with the phospholipids. Apparent particle weight of the complex including bound detergent was 520 ± 46 kDa. The secondary quinone QB was partially removed from the RC by treatment with 2 -3 % octaethyleneglycol dodecyl ether and 3 -4 mᴍ orthophenanthroline. Reconstitution experi­ments showed that UQ6, UQ9 and UQ10 could replace QB but that MK8 and MK9 could not. It was concluded that QB site has a clear specificity towards ubiquinone binding.

Reaction of Fluorescein Isothiocyanate with Thiol and Amino Groups of Sarcoplasmic ATPase

1985 ◽  
Vol 40 (11-12) ◽  
pp. 863-875 ◽  
Author(s):  
Gertrude Swoboda ◽  
Wilhelm Hasselbach
Keyword(s):  
Absorption Maximum ◽  
Sodium Dodecylsulfate ◽  
Specific Effect ◽  
Fluorescein Isothiocyanate ◽  
Thiol Groups ◽  
Amino Groups ◽  
Model Compounds ◽  
Intramolecular Transfer ◽  
Dodecyl Ether ◽  
Lysyl Residue

Abstract Several model compounds containing thiol and/or amino groups (mercaptoethanol, glutathione, cysteine, ethanolamine, glycine) were studied with respect to their reactivity towards fluorescein isothiocyanate (followed spectrophotometrically at 504 and 412 nm), stability of product and long­ wave absorption maximum of the fluorescein residue attached. Thiol groups reacted by far more readily than amino groups. A specific effect was observed with cysteine, indicating an intramolecular transfer of the fluorescein residue from SH to NH2.With sarcoplasmic vesicles both types of reactions were observed. The ratio of products, which can be distinguished by their different stabilities and absorption spectra, depended on the absence or presence of detergents. While with native vesicles the NH2 reaction predominated, with vesicles solubilized with sodium dodecylsulfate, octaethyleneglycol mono-n-dodecyl ether or 1-0-tetradecyl-propanediol-(1,3)-3-phosphorylcholine the SH reaction became prevailing. Already 0.35 mg sodium dodecylsulfate per mg protein were sufficient to give rise to dithiourethane formation exclusively. Excess fluorescein isothiocyanate reacted with several thiol groups of dodecylsulfate-solubilized vesicles. In the presence of ATP binding of fluorescein isothiocyanate to native vesicles was significantly reduced.Total blockage of the vesicular SH groups with N-ethyl-maleimide led to preparations that reacted with fluorescein isothiocyanate much more slowly, compared to native vesicles. Octaethy­ leneglycol mono-n-dodecyl ether or 1-0-tetradecyl-propanediol-(1,3)-3-phosphorylcholine in the assay accelerated the thioureide formation from N-ethylmaleimide modified vesicles, whereas sodium dodecylsulfate prevented it almost completely.Our results support the suggestion that one or several thiol groups in vicinity of the highly reactive lysyl residue might play a role in the fast specific reaction, which is only observed with intact native vesicles.

Cocklebur Control in Soybeans with 2,4-DB and Chloroxuron

Weed Science ◽  
1972 ◽  
Vol 20 (5) ◽  
pp. 489-491 ◽  
Author(s):  
B. J. Gossett ◽  
L. R. Reinhardt ◽  
W. P. Byrd
Keyword(s):  
Glycine Max ◽  
Polyethylene Glycol ◽  
Butyric Acid ◽  
Crop Injury ◽  
Seed Yields ◽  
Dodecyl Ether

Foliar-applied 3-[p-(p-chlorophenoxy)phenyl]-1,1-dimethylurea (chloroxuron), chloroxuron with dodecyl ether polyethylene glycol surfactant, and dimethylamine salt of 4-(2,4-dichlorophenoxy)butyric acid (2,4-DB) effectively controlled cocklbur(Xanthiumsp.) in soybeans(Glycine max(L.) Merr. ‘Hampton’ or ‘Lee’). While treatments caused crop injury, treated soybeans produced higher seed yields than untreated soybeans infested with cocklebur plants. Seed yields from soybeans growing free of cocklebur were not reduced by treatment with chloroxuron or chloroxuron with surfactant but in some cases were reduced by 2,4-DB treatment.

Sign in / Sign up

Export Citation Format

Share Document