Detergents, membrane protein solubilization

Solubilize desaturases with 1 % CHAPS at a detergent-membrane protein ratio of equal to one, 5°C for 30 min with gentle stirring. 

Nielson, C. S. and Bjerrum, 0. J. 1977. Crossed immunoelectrophoresis of bovine milk fat globule membrane protein solubilized with non-ionic detergent. Biochim. Biophys. Acta 466, 496-509. 

Luche, S., Santoni, V. and Rabi I loud, T. (2003) Evaluation of nonionic and zwitterionic detergents as membrane protein solubilizers in two-dimensional electrophoresis. Proteomics 3, 249-253. 

Figure 12.2 (a) Schematic drawing of membrane proteins in a typical membrane and their solubilization by detergents. The hydrophilic surfaces of the membrane proteins are indicated by red. (b) A membrane protein crystallized with detergents bound to its hydrophobic protein surface. The hydrophilic surfaces of the proteins and the symbols for detergents are as in (a). (Adapted from H. Michel, Trends Biochem. Sci. 8 56-59, 1983.)... 

It is emphasized that revealing the dynamics as well as the structure (or conformation) based on several types of spin-relaxation times is undoubtedly a unique and indispensable means, only available from NMR techniques at ambient temperature of physiological significance. Usually, the structure data themselves are available also from X-ray diffraction studies in a more refined manner. Indeed, better structural data can be obtained at lower temperature by preventing the unnecessary molecular fluctuations, which are major subjects in this chapter, since structural data can be seriously deteriorated for domains where dynamics are predominant even in the 2D or 3D crystalline state or proteoliposome at ambient temperature. It should be also taken into account that the solubilization of membrane proteins in detergents is an alternative means to study structure in solution NMR. However, it is not always able faithfully to mimick the biomembrane environment, because the interface structure is not always the same between the bilayer and detergent system. This typically occurs in the case of PLC-81(1-140) described in Section 4.2.4 and other types of peptide systems. 

M. le Maire, P. Champed, J. V. Moller (2000) Interaction of membrane proteins and lipids with solubilizing detergents. Biochim. Biophys. Acta, 1508 86-111... 

Subsequent to possible solubilization of membrane-bound proteins, solubilization must be verified. The criteria listed in Table 2 are relevant in assessing whether solubilization has been accomplished. To ascertain whether the solubilized protein has retained biological activity, membrane reconstitution (28) is attempted subsequent to detergent removal (24). Reconstitution is often visualized by electron microscopy employing either negative staining or freeze fracture. 

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. 

An important advantage of using SDS to denature polypeptides is the solubilizing power of the detergent. This property allows for the study of proteins (e.g., membrane proteins) that easily precipitate under most other conditions. 

Solubilization Procedures Detergents An overview, 182, 239 solubilization of functional membrane proteins, 104, 305 solubilization of native membrane proteins, 182, 253 solubilization of protein aggregates,182, 264 removal of detergents from membrane proteins, 104, 318 182, 277. 

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