Dodecyl maltoside

The surfactant dienes 90 and 91 (Figure 4.3), analogs to commercially available sodium dodecyl sulfate (SDS) and dodecyl maltoside, react rapidly with highly hydrophilic and reactive triazoline dione 92 in water at 25 °C forming, quantitatively, the corresponding adducts. The Diels-Alder reactions with less potent dienophile 93 gave, similarly, quantitative yields in 0.5 h and 3 h with 90 and 91, respectively. 

A recent review of the detergent literature indicated the following trends (1) improvement in dodecyl maltoside surfactants (73), (2) expansion of the use of Triton detergents in biochemistry (74), and (3) the use of detergents for solution nuclear magnetic resonance studies (75). 

Lambert O, Lev D, Ranck J-L, Leblanc G, Rigaud J-L. A new gel-like phase in dodecyl maltoside-lipid mixtures implications in solubilization and reconstitution studies. Biophys J1998 74 918-930. 

De La Maza A, et al. Biopolymer excreted by Pseudoalteromonas antarctica NF3, as a coating and protective agent of liposomes against dodecyl maltoside. Biopolymers 1999 50(6) 5795-5788. 

The PSI-200 preparation can be subjected to further fractionation by solubilisation in the detergent dodecyl maltoside, followed by sucrose gradient ultracentrifugation (Bassi and Simpson 1987c). This... 

III. Structure and Dynamics of Rhodopsin in Solutions of Dodecyl Maltoside ... 

Cysteine-scanning mutagenesis, involving more than 100 mutations, has been systematically carried out through Cl—C3, the cytoplasmic terminations of TM1-TM7, H8, and the C-terminal tail. In addition, more than 40 pairs of cysteines have been introduced at the cytoplasmic face. With these mutants as a basis set, three classes of experiments have been carried out, namely SDSL, sulfhydryl reactivity, and disulfide cross-linking kinetics. A global comparison of the results provides a unique view of the solution state, its dynamics, and its correlation with the crystal structure. By solution state is meant, in all cases, rhodopsin solubilized in dodecyl maltoside (DM) micelles. The measured functional properties of rhodopsin, namely transducin activation (Resek et al., 1993) and phosphorylation by the rhodopsin kinase (Thurmond et al., 1997), are conserved in this detergent, and it is presumed to be a reasonable approximation to the bilayer environment. 

Orthorhombic crystals obtained from the preparations stabilized with the detergent decyl maltoside diffracted X-rays up to a maximum resolution of 2.3 resolution from non-frozen crystals (Yoshikawa et ah, 1998). No commercially available detergent other than decyl maltoside has been found that will produce orthorhombic crystals. Even dodecyl maltoside, only two alkyl chain units longer than decyl maltoside, did not produce crystals even though the detergent stabilizes the enzyme effectively. It should... 

Thylakoids were prepared from wheat and pea leaves as described previously (7). PSII reaction centres were prepared from Triton X-lOO-solubilised pea thylakoids and exchanged into "maltoside buffer" (2 mM dodecyl maltoside in 50 mM Tris-Cl pH 7.2) as described elsewhere (8). 

The reaction centre complex as prepared by the method of Nanba and Satoh (1) is unstable. Increased stability of the complex occurs when the Triton X-100 is exchanged for a detergent such as dodecyl maltoside (3,4). 

Figure lA and 1C show that a decrease in the Triton X-100 concentration from 0.2 to 0.033% resulted in an increase in the yield of spin polarised triplet as did replacement of the Triton X-100 with dodecyl maltoside (not shown).In concentrated samples a delta iiw = 2 triplet was also seen at half field. 

The PSII reaction centre was isolated as described in ref. 1. In the initial experiments the samples contained Triton-XlOO, but in later measurements dodecyl maltoside replaced the Triton. No difference was observed between the two preparations in EPR kinetics. The samples were diluted with 50 mM tris-HCl pH 8.0 to a concentration of 80 ig chl/ml. 10 mg/ml Na dithionite was added. After dark adaptation, the samples were cooled rapidly in complete darkness to 77 K. 

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