Simple hydrophobic reagents

A simple hydrophobic reagent is a small radiolabeled organic molecule that can be photochemically activated after it has bound to a lipid bilayer. The major merit of such reagents in comparison to phospholipid analogs is that they are simple to use with native membranes. Klip and Gitler (1974) 

The question of reactivity has two facets. First, a very reactive intermediate will be short-lived and for two reagents of similar hydrophobicity the more reactive one will be less likely to dissociate from and react outside the lipid bilayer (Bayley and Knowles, 1978a,b). Second, as mentioned 

Comparison of three well-characterized hydrophobic reagents3 

Reagent Structure tnax p, b rbc Reactive species References 

Iodonaphthylazide 125 691 N3 310 nm/21,400 163,000 Nitrene and azacyclo-heptatetraene or benzazirine Berovici et al. (1978), Kahane and Gitler (1978), Karlish et al. (1977), Tarrab-Hazdai et al. (1980) 

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Many of the matters that were considered for simple hydrophobic reagents apply to amphipathic molecules and they will not be discussed again here. Like hydrophobic reagents, properly designed amphipathic reagents are convenient to use as they may be added directly to samples... 

The looping around of photoactivated fatty acyl chains to the membrane surface, with subsequent reaction there or at an intervening point, is a distinct possibility (Bayley and Knowles, 1978a). Such events would be analogous to the exchange of simple hydrophobic reagents into the aqueous phase resulting in the derivatization of peripheral proteins, but in the case... 

Statistical mechanical treatments fail to address the dispersion and polarization interactions that are particularly important when hydrophobic reagents such as IPRs are dealt with [46]. The quantitative treatment of these interactions was introduced by Bockris, Bowler-Reed, and Kitchener [47] their work is important for explaining anomalous salting in when the simple electrostatic theory would predict salting onL... 

Li et al. developed a simple and versatile strategy for converting hydrophobic rare earth nanophosphors into water-soluble and carboxylic acid-functionalized analogues. The surface oleic acid ligands could be directly oxidized by the Lemieux-von Rudloff reagent, and the modified NCs kept the excellent luminescence and were further used as DNA labels (Figure 77) (Chen et al., 2008c). 

Where impurities are present as microparticulate material filtration affords a convenient technique for solvent purification. The mobile phase containing added buffers or reagents may be filtered through a 0.5 pm or smaller filter to remove particulate matter that can damage the analytical system. The equipment for filtration is simple. Usually, it consists of an Elenmayer flask connected to vacuum and a reservoir in which a porous filter disk or membrane is placed. The porous disk is usually made from nonporous spherical glass beads (1-2 pm) and/or polytetrafluoroethylene (PTEE). Membrane materials are usually made from PTEE, cellulose, or nylon. To improve the efficiency of the separation process, the surface of the filter disks or membrane surface are often modified chemically, similar to that used for chemically bonded packing materials in RP-HPLC and/or SPE. In this case, the surface properties (hydrophobic or hydrophilic) of filters and/or membranes determine the extent of purification possible. 

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