Octyl glucosides

FIGURE 3 Effect of the amount of cholesterol on the particle size. Phosphatidylcholine/cholesterol liposomes were prepared by the octyl glucoside dilution technique. The begin concentration of the mixed micelles was 150 mM octyl glucoside and 10 mM phosphatidylcholine in 10 mM tris(hydroxymethyl)aminomethane and 0.9% NaCl, pH 7.4. Dilution was performed with an automatic titration unit at a dilution rate (= dilution factor, relative to the initial volume, per unit of time) of 0.026 sec"l ( a and ) or 0.69 sec l ( and o). Mean diameters after dilution and ) and after filtration ( L and q) are repi sented. (Adapted from Jiskoot et al, 1986a.)... 

Jopski B, Pirkl V, Jaroni HW, et al. Preparation of hemoglobin-containing liposomes using octyl glucoside and octyltetraoxyethylene. Biochim Biophys Acta 1989 978 79. 

Ollivon M, Eidelman O, Blumenthal R, Walter A. Micelle-vesicle transition of egg phosphatidylcholine and octyl glucoside. Biochemistry 1988 27 1695. 

Almog S, Litman BJ, Wimley W, et al. States of aggregation and phase transformations in mixtures of phosphatidylcholine and octyl glucoside. Biochemistry 1990 29 4582. 

A similar activity level was obtained in the deoxycholate, Triton X-100, and NP-40 extract preparations. Octyl glucoside and CHAPS extract preparations showed no detectable prephenate aminotransferase activity. When the hemoglobin step was used, there was no increase in the soluble activity recovered in the initial supernatant fraction, but the specific activity of the deoxycholate (the only detergent tried in this experiment) extract increased about tenfold. We would anticipate equally good results with use of Triton X-100 or NP-40 in combination with the hemoglobin step. 

S.A. = 0.67 in octyl glucoside buffer) could be found in all of the detergent-extract preparations. As above, the hemoglobin step increased dramatically the S.A. of shikimate dehydrogenase assayed in detergent-extract preparations. 

In 1985 Tyminski etal. [55, 56] reported that two-component lipid vesicles of a neutral phospholipid, e.g. DOPC, and a neutral polymerizable PC, bis-DenPC (15), formed stable homogeneous bilayer vesicles prior to photopolymerization. After photopolymerization of a homogeneous 1 1 molar lipid mixture, the lipid vesicles were titrated with bovine rhodopsin-octyl glucoside micelles in a manner that maintained the octyl glucoside concentration below the surfactant critical micelle concentration. Consequently there was insufficient surfactant to keep the membrane protein, rhodopsin, soluble in the aqueous buffer. These conditions favor the insertion of transmembrane proteins into lipid bilayers. After addition and incubation, the bilayer vesicles were purified on a... 

Dissolve 5.04 g urea (final 8 M) and 788 (J.1 carrier ampholyte mixture (e.g., Pharmalyte Amersham Pharmacia Biotech final 7.5%) in water to 10.5 ml. Add a reducing agent (60 mM dithiothreitol) and/or a detergent (0.5% [w/v] Triton X-100, CHAPS, or octyl glucoside), if desired. Make fresh. 

Many protein samples require the use of detergents for their solubilization. For IEF work, the zwitterionic detergents CHAPS and CHAPSO, or the nonionic detergent octyl-glucoside, at concentrations of 1-2% in the gel are recommended. Even in the presence of detergents, some samples may have stringent salt requirements and may aggregate in salt-free environments. 

The ideal sample run on the Rotofor cell would contain only the protein mixture, water, and ampholytes or buffers. However, pi precipitation may require that 3 M urea be included for solubility. When higher urea concentrations are needed, the Rotofor cell is run at 12°C. Detergents (1-2% w/v) may also be added to samples. Zwitterionic detergents, such as CHAPS, CHAPSO, and nonionic octyl-glucoside are satisfactory. 

Normal aqueous micellar media can also be employed to extract and purify components from solid matrices. Proteins have been extracted from wheat kernals using aqueous NaLS (399). This same surfactant system has been employed in an improved method for the extraction of filth from cheese (417). In another application, aqueous solutions of Brij-35 micelles have been employed to extract components (i.e. vanillin and ethylvanillin) from smoking tobacco (106). In a similar manner, various phenolic compounds have been extracted from herbal/plant leaves using nonionic Triton X-100, Brij-35, or octyl glucoside (0G) (393). In both of these latter examples, the indicated compounds could be identified and quantitated by reversed phase HPLC using as mobile phase the same micellar solutions (refer... 

Twelve ordered octyl glucoside molecules are associated with the aromatic regions near the external side of each tetramer (Fig. 4). The pyranoside rings interact laterally with the external tryptophan/tyrosine layer, while the alkyl chains extend toward the hydrophobic core. 

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