Sodium dodecylsulfate electrophoresis

Size Isomers. In solution, hGH is a mixture of monomer, dimer, and higher molecular weight oligomers. Furthermore, there are aggregated forms of hGH found in both the pituitary and in the circulation (16,17). The dimeric forms of hGH have been the most carefully studied and there appear to be at least three distinct types of dimer a disulfide dimer connected through interchain disulfide bonds (8) a covalent or irreversible dimer that is detected on sodium dodecylsulfate- (SDS-)polyacrylamide gels (see Electroseparations, Electrophoresis) and is not a disulfide dimer (19,20) and a noncovalent dimer which is easily dissociated into monomeric hGH by treatment with agents that dismpt hydrophobic interactions in proteins (21). In addition, hGH forms a dimeric complex with ( 2). Scatchard analysis has revealed that two ions associate per hGH dimer in a cooperative... 

First Dimension Optimization After the second-dimension separation has been developed, the first-dimension flow rate is determined. This includes selecting a first-dimension column diameter to work at the flow rate selected. We illustrate the selection process with an application that addresses a column method for proteins that functions as a replacement for planar 2D gel electrophoresis (2DGE) within a narrow molecular weight and p/range. In the planar experiment, isoelectric focusing is performed in the first dimension and sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS/PAGE) in the second dimension. 

Fig. 1.2 Protein blot analysis of human therapeutic protease inhibitor (HTPI) produced in alfalfa cell cultures using different promoters and subcellular targeting peptides as shown. Equal amounts of total soluble proteins from cell cultures were separated by sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and blotted onto a polyvinyldifluoride (PVDF) membrane. Monoclonal anti-HTPI IgGs were used for detection.

The basic material in seeds that is extractable with trichloroacetic acid solutions is ascribed to nonprotein nitrogen when the acid is in the 0.4-1.0 M concentration range. Gel electrophoresis on a sodium dodecylsulfate polyacrylamide medium pointed to the presence of 12 kDa polypeptides in soybean meal and 7, 10, 12 and 28 kDa in almond meal332. 

Sample preparation. All allantoic fluid of chicken embryos or calf serum used in experiments contained influenza virus (104—106 EID50/ml). The samples of biological fluids underwent photodynamic treatment as described above. One milliliter aliquots were taken before treatment and at 3 and 6 h after the start of experiment. To analyze the effect of photodynamic treatment on proteins we used alkaline denaturing electrophoresis in the presence of sodium dodecylsulfate (SDS) and P-mercaptoethanol (P-ME). 

Thin-layer chromatography (75) and sodium dodecylsulfate-(poly)acrylamide gel electrophoresis (SDS-PAGE) are helpful for analyses of the lipid and protein composition, respectively. Size-exclusion chromatography allows estimation of the size distribution of the (proteo)liposomes and crude fractionation of the material as reviewed in Ref. 76. Accurate determinations of size distributions require analyses by static or dynamic... 

Parekh, B. S, Mehta, H. B., West, M. D., and Montelaro, R. C. (1985) Preparative elution of proteins from nitrocellulose membranes after separation by sodium dodecylsulfate-polyacrylamide gel electrophoresis Anal Biochem 148, 87-92... 

Several of the synthetic detergents used for dissolving membranes and solubilizing integral membrane proteins. Triton X-100 and octylglucoside are nonionic detergents cetyltrimethylammonium bromide and sodium dodecylsulfate (SDS) are ionic. SDS is also an effective denaturant of proteins and is used in polyacrylamide-gel electrophoresis (see chapter 6). 

Maizel introduced the use of sodium dodecylsulfate (SDS) for high-resolution electrophoresis of protein mixtures. 

Index Entries Recombinant green fluorescent protein GFPuv hydro-phobic interaction chromatography sodium dodecylsulfate polyacrylamide gel electrophoresis three-phase partitioning extraction. 

Jann, B., Reske, K., Jann, K. Heterogeneity of lipopolysaccharides. Analysis of polysaccharide chain lengths by sodium dodecylsulfate-polyacrylamide gel electrophoresis. Eur J Biochem 60 (1975) 239-246. 

Answer Treat a suspension of the bacteria as follows Add lactose at a concentration well above the A), so that virtually every molecule of galactoside transporter binds lactose. Next, add nonradiolabeled NEM and allow it to react with all available —SH groups on the cell surface. Remove excess lactose by centrifuging and resuspending the cells, then add radiolabeled NEM. The only Cys residues now available to react with NEM are those in the transporter protein. Dissolve the membrane proteins in sodium dodecylsulfate (SDS), and separate them on the basis of size by SDS gel electrophoresis. The Mt of the labeled band should represent that of the galactoside transporter. 

If a further purification is desired, then the supernatant (above) can be subjected to ammonium sulfate fractionation, gel filtration on Sephadex G-200, and finally on a-aminopropane-agarose affinity column. On polyacrylamide gel electrophoresis in the presence of sodium dodecylsulfate, the final product migrated as a single band with an estimated molecular weight of 113,000. Upon sedimentation equilibrium velocity ultracentrifugation, an estimated molecular weight value of near 117,000 was obtained. 

Capillary SDS-gel electrophoresis is a rapid automated separation and characterization technique for protein molecules and is contemplated as a modern instrumental approach to sodium dodecylsulfate-polyacrylamide slab-gel electrophoresis (SDS-PAGE). Size separation of SDS-protein complexes can be readily attained in coated capillaries filled with cross-linked gels or non-cross-linked polymer networks. Figure 9 depicts one of the early applications of the technique for the analysis of a standard protein test mixture ranging in size from 14.2 to 205 kDa. 

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