Electrophoresis on polyacrylamide

Escherichia coli contains one RNA polymerase, which transcribes all three major types of RNA. The active enzyme is a pentamer containing four different polypeptide chains with a total molecular weight of about 500,000. The subunits of the enzyme can be separated by electrophoresis on polyacrylamide gels. The four different polypeptide chains, termed j8, /3, a10, and a, have molecular weights of 155,000, 151,000, 70,000, and 36,500, respectively. Additional cr-like proteins have been identified, which we discuss later. 

Sims, M., Methods for detection of enzymatic activity after electrophoresis on Polyacrylamide Gel in Drosophila species. Nature 207, 757-758 (1965). 

Horse serum butyrylcholinesterase isoenzymes have been resolved by electrophoresis on polyacrylamide gel, and the differential reactivity of the various isoenzymes toward butyrylthiocholine has been measured simultaneously in a single gel (C7). The results are shown in Table 5. Only 63 % of the total enzymic activity was found to be associated with the major component (CJ, compared with 80% found by previous investigators (S49). 

Analytical Techniques and Physical Methods.— The mapping of oligonucleotides and nucleic acid digests on cellulose or cellulose-polyethyleneimine has been described recently, and columns of mercurated dextran or dihydroxyborylcellulose have been used to fractionate nucleotide mixtures. Electrophoresis on polyacrylamide gels has been advocated as a rapid method for desalting and fractionating mixtures of oligonucleotides. ... 

Paetzold et al. (1990) obtained similar results by fractionating proteins from Sauvignon Blanc must using electrophoresis on polyacrylamide gel, followed by chromatofocusing. Proteins in must from this grape variety have molecular weights between 13 000 and 67 000 Da (Figure 5.10) and a... 

Fig. 5.10. Separation of proteins from Sauvignon Blanc must and wine by electrophoresis on polyacrylamide gel under denaturing conditions (Moine-Ledoux, 1996)...

Radioactive metabolites are often separated by electrophoresis on polyacrylamide gels. The subsequent liquid scintillation analysis of the radioactivity is usually performed after treatment with some quarternary ammonium base solubilizer. 

Fig. 4. Electrophoresis on polyacrylamide gels of HCl-soluble proteins from testis (a) and liver b) at pH 2.9 (/) or on reducing SDS gels (II). The purity of the 70,000 Mj- proteins from testis (c) and liver (d) are shown after elution from gel slices...

These encouraging results led to further attempts to purify the hormone. Sephadex filtration, first on G50 and later on GlOO, followed by chromatographic analysis on a carboxymethyl-cellulose column, and finally electrophoresis on polyacrylamide gel yielded two different polypeptides. Enough of the two polypeptides could be obtained to compare their properties. Although the polypeptides differed by their mobilities and amino acid composition, their biological and immunological properties were identical. 

The monomer has a sedimentation constant of 3 and a molecular weight of 11,500. When the monomer is submitted to electrophoresis on polyacrylamide gel in 8 M urea at pH 10.2, two bands are obtained. But the meaning of this finding is not clear. 

P-D-2-Acetamido-2-deoxyhexosidase from bull epididymis has been purified by affinity chromatography on a benzidine derivative of agarose to which monosaccharide lactones had been covalently attached. The use of 2-acetamido-2-deoxy-D-mannono-1,5-lactone is advantageous, and the enzyme fraction obtained could be separated into two bands, one of which was enzymically active, by electrophoresis on polyacrylamide gel. 

Disk electrophoresis on polyacrylamide gels of the denatured enzyme-[ S]MMPR-OP complex is carried out to determine the subunit bound by the affinity label. ... 

The inactivated enzyme and the native isomerase are electropho-retically distinct, yielding Rj values of 0.51 and 0.54, respectively, upon electrophoresis on polyacrylamide gels at pH 9. 

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