Differential solubilization

Banerjee R, Jao JB, Bush JT, Dawson G. Differential solubilization of lipids along with membrane proteins by different classes of detergents. Chem Phys Lipids 1995 77 65-78. 

Molloy MP, Herbert BR, Walsh BJ, et al. (1998) Extraction of membrane proteins by differential solubilization for separation using two-dimensional gel electrophoresis. Electrophoresis 19, 837- 4. 

The basis for separation employing micellar mobile phases stems from their ability to differentially solubilize and bind structurally similar solutes. Skeptics view MLC as a fascinating example of the incorporation of secondary equilibria for control or adjustment of retention (101). However, it is the ultimate of secondary equilibria since the types of interactions possible with micellar aggregates cannot be duplicated by any single other equilibrium system, or for that matter, any one or mixture of traditional normal or reversed phase mobile phase systems. This is due to the fact that solutes can interact with the surfactant aggregates via hydrophobic, electrostatic, hydrogen bonding, and/or a combination of these factors. 

Bacteria can promote differential solubilization of the constituents of rock, ore and minerals. One such example is the differential... 

The haemolytic activities of natural CyDs are reported to be in the order p- > a- > y-CyD. These differences are ascribed to the differential solubilization of membrane components by each CyD. When the CyD cavity is modified by chemical derivatization, its effects on cell membranes can be changed dramatically from those of parent CyDS. When the muscle tissue damage due to the injection of hydrophilic CyDs was compared with that of mannitol and nonionic surfactants, following a single injection (100 mg ml" ) of the compounds into M. vastus lateralis of rabbits (Fig. 38.2), a-CyD and DM-P-CyD showed a relatively high irritation reaction, the degree of... 

Dijferential solubilization, where micelles interact preferentially with one of the co-crystal components, is the underlying mechanism by which otherwise unstable co-crystals achieve thermodynamic stability in micellar solutions. This concept was recently reported and applied to describe the behavior of several co-crystals." " Pharmaceutical co-crystals generally comprise a hydrophobic drug and a relatively hydrophilic co-former, thus, differential solubilization may be widely encountered. This finding has important implications for the characterization of co-crystal solution behavior and can lead to huge errors in the evaluation of co-crystal solubility and dissolution if not recognized. 

Figure 11.9 Differential solubilization of co-crystal components represented by the relative values of and Ks leads to nonlinear co-crystal solubility dependence and to intersection of the co-crystal and drug solubility curves. CSC refers to the critical stabilization concentration, at which both co-crystal and drug are thermodynamically stable. Adapted with permission from Huang and Rodriguez-Hornedo, ref. 45. Copyright 2010 American Chemical Society.

Efforts to solubilize and isolate the P-450 monoxygenases from the microsomal membranes have been hampered by the facile conversion to a catalytically inactive form, cytochrome P-420. In 1968, however, a successful solubilization of catalytically active P-450 from hepatic microsomes was reported.30, 31 he solubilized system, which effected w-hydroxylation of fatty acids, required three coiq>onents for catalytic activity cytochrome P-450, NADPH-cytochrome c reductase, and a heat-stable, chloroform-soluble factor, the active component of which was identified as the microsomal lipid phosphatidylcholine.32 Further studies with this solubilized and reconstituted system have Indicated that the cytochrome P-450 and P-448 fractions have different catalytic activities 33-35 and that the terminal oxidase activity resides in the b-type cytochrome (P-450 or P-448) fraction rather than the cytochrome c reductase or lipid fractions.33, 36, 37 xhe cytochrome P-450 and P-448 were found to coiq>ete for reductase when present together.38 Cytochrome bs did not appear to be an obligatory component of the reconstituted systera.39 Cytochrome P-450 and P-448 fractions from rat liver were found to contain high levels of an epoxide hydrase, which can convert intermediate oxides to vicinal diols. Further purification has afforded fractions relatively free of cross-contamination of monoxygenase and hydrase enzymes. Recently, differential solubilization of monoxygenase activity towards a Type I substrate (naphthalene) and a Type II substrate (aniline) was... 

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