Sodium dodecyl sulfate -protein complexes

Dittman, M. M. and Rozing, G. R, High-sensitivity separations of sodium dodecyl sulfate-protein complexes with capillary gel electrophoresis, LC-GC, 17(2), 132, 1999. 

A. Gerstner, Z. Csapo, M. Sasvari-Szekely, and A. Guttman, Ultrathin sodium dodecyl sulfate gel electrophoresis of proteins Effect of gel composition and temperature on the separation of sodium dodecyl sulfate-protein complexes, Electrophoresis, 21, 834 (2000). 

Figure 4.7. Polyacrylamide Gel Electrophoresis. (A) Gel electrophoresis apparatus. Typically, several samples undergo electrophoresis on one flat polyacrylamide gel. A microliter pipette is used to place solutions of proteins in the wells of the slab. A cover is then placed over the gel chamber and voltage is applied. The negatively charged SDS (sodium dodecyl sulfate)-protein complexes migrate in the direction of the anode, at the bottom of the gel. (B) The sieving action of a porous polyacrylamide gel separates proteins according to size, with the smallest moving most rapidly.

Giordano, B.C., Couch, A.J., Ahmadzadeh, H., Jin, L.J., Landers, J.P., Dynamic labeling of protein-sodium dodecyl sulfate (SDS) complexes for laser induced fluorescence (LIF) detection on microchips. Micro Total Analysis Systems, Proceedings 5th l TAS Symposium, Monterey, CA, Oct. 21-25, 2001, 109-110. 

Prokaryotic cells express hundreds to thousands of proteins while higher eukaryotes express thousands to tens of thousands of proteins at any given time. If these proteins are to be individually identified and characterized, they must be efficiently fractionated. One-dimensional sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) has typically been use to study protein mixtures of <100 proteins. Onedimensional electrophoresis is useful because nearly all proteins are soluble in SDS, molecules ranging from approximately 10,000 to 300,000 molecular weight can be resolved, and extremely basic or acidic proteins can be visualized. The major disadvantage to one-dimensional gels is that they are not suitable for complex mixtures such as proteins from whole cell lysates. 

Karim, M.R., Shinagawa, S., Takagi, T. (1994). Electrophoretic mobilities of the complexes between sodium dodecyl sulfate and various peptides or proteins determined by free solution electrophoresis using coated capillaries. Electrophoresis 15, 1141-1146. 

Mattice, W.L., Riser, J.M., Clark, D.S. (1976). Conformational properties of the complexes formed by proteins and sodium dodecyl sulfate. Biochemistry 15, 4264 4272. 

Recently, novel polymethine carbonyl-dyes based on coumarin moiety and their boron difluoride complexes 9a-d and lOa-d [34—36] were evaluated as fluorescent dyes for the detection of native proteins using bovine serum albumin (BSA) as a model protein, and as probes for the nonspecific detection of proteins using a BSA/ sodium dodecyl sulfate (SDS) mixture [37]. Optical properties of these compounds in the absence and presence of BSA, as well as in SDS and BSA/SDS mixture, were measured in Tris-HCl buffer (pH 8.0) (Table 1). 

Anderson, M., Cawston, T. and Cheeseman, G. C. 1974. Molecular weight estimates of milk fat globule membrane protein-sodium dodecyl sulfate complexes by electrophoresis in gradient acrylamide gels. Biochem. J. 139, 653-660. 

This can be done by the Ouchterlony diffusion technique (see Fig. 2 and ref. 6). by enzyme-linked immunosorbent assay (see Chapter 15), or by Western blot, either using the purified protein or a more complex mixture of proteins containing the antigen of interest separated on a sodium dodecyl sulfate-polyacrylamide gel electrophoresis gel (see Chapter 20). 

Regardless of the chromatography method that is used, fractions containing subsets of the proteins in the sample are collected at the bottom of the column. Each of the fractions is assayed for enzyme activity. In addition, the complexity of the fraction is evaluated by separating the proteins in a small sample of the fraction using sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE). This method separates proteins in mixtures based on their size. 

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