Sodium dodecyl sulfate-polyacrylamide isolation

It is unlikely that the protein fractions from this experiment contain a single type of protein. How many different proteins are present What is the relative abundance of each protein Is a-lactalbumin the predominant protein in the isolated fractions What are the approximate molecular weights of a-lactalbumin and other proteins These questions may be answered by analysis of the isolated fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) (see Chapter 4). The technique of SDS-PAGE will be introduced and applied to the column-purified fractions, crude whey fraction, and standard a-lactalbumin. 

M Schuhmacher, MO Glocker, M Wunderlin, M Przybylski. Direct isolation of proteins from sodium dodecyl sulfate-polyacrylamide gel electrophoresis and analysis by electrospray-ionization mass spectrometry. Electrophoresis 17 848-854, 1996. 

Link protein preparations from most cartilages, isolated as described above, contain two proteins approximately 44,000 and 48,000 in molecular weight, on sodium dodecyl sulfate polyacrylamide gel electrophoresis. These two proteins have been called link proteins 1 and 2. Molecular weights of link proteins 1 and 2 from several cartilages are given in Table II. 

Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) has also been successfully used in both one and two dimensions to isolate discrete proteins from DON (e.g., Jones et al, 2004 Tanoue, 1995 Yamada and Tanoue,... 

Fig. 5.5. Crosslinking of a and P subunits of F, at the catalytic site with 3 -0- 3-(iV-(4-a2ido-2-nitrophenyl)amino]propionyl)8-azido-adenosine 5 -triphosphate. The crosslinked product (molecular weight, 120000) was isolated by sodium dodecyl sulfate polyacrylamide gel electrophoresis, and then hydrolyzed at the position shown by an arrow. Analysis of each fraction confirmed the structure [73].

Epstein-Barr virus (EBV)-transformed homozygous human B-cell lines were used as a source for isolating HLA class II molecules. In the case of isolation of HLA-DR1, WT-100 cell pellets were lyzed by NP-40, and DR1 was isolated from homogenates by affinity chromatography with the monoclonal antibody L243 essentially as described [64,65].The purity of the preparation was analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), HPSEC and Western blotting. 

Khan, K. and Bushuk, W. Studies of Glutenin. XII. Comparison by sodium dodecyl sulfate-polyacrylamide Gel Electrophoresis of unreduced and reduced Glutenin from various isolation and purification procedures. Cereal Chem. 56 63-68, 1979. 

Photo system I (PS I) preparations from barley contain polypeptides with apparent molecular masses of 82 (PSI-A and PSI-B), 18 (PSI-D), 16 (PSI-E), 14, 9.5 (PSI-H), 9 (PSI-C), 4, and 1.5 kDa (PSI-I) as determined by sodium dodecyl sulfate polyacrylamide gel electrophoresis (1, 2). The nomenclature used for the subunits is described in more detail by Moller et al. (3). In this paper we report the characterization of a cDNA clone for the PsaE gene encoding the 16-kDa polypeptide PSI-E. The molecular mass of the mature polypeptide is 10,821 Da when deduced from the nucleotide sequence. To test whether the discrepancy between the molecular mass determinations could be due to post-translational modification of the polypeptide, the isolated polypeptide was analyzed by plasma desorption mass spectrometry. It has previously been established that the N- and C-terminal amino acid residues of the PSI-E polypeptide are not modified (4). 

The NAD glycohydrolase was isolated and purified [14] from SMP to apparent homogeneity as judged by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and showed a mol.wt. of about 64,000. The purified enzyme had highest activity with NAD, moderate activity with NADP, and was inactive with NAD(P)H. 

The ADP-ribosylation reaction is stimulated by GTP, phospholipids, and various cellular factors, both membrane and soluble (2-9). Kahn and Gilman (7, 9) isolated a membrane protein termed ADP-ribosylation factor (ARF) that promoted the toxin-catalyzed ADP-ribosylation of Gso. The protein bound GTP in a reaction which was enhanced by NaCl and dimyristoyl phosphatidylcholine (9). It was proposed that ARF boimd directly to Gso (7) and Aat the ARF Gso complex served as the actual substrate in the toxin-catalyzed reaction (7). Tsai et cd. (10) demonstrated that ARF from bovine brain membranes activated the toxin directly rather than interacting with the substrate Gso. Other factors that enhanced the ability of choleragen to ADP-ribosylate Gso were identified in a soluble fraction from bovine brain. Two proteins that accoimted for most of the choleragen activation by the soluble fraction were resolved by ion exchange chromatography and separately purified. Each exhibited one major band by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. 

A general picture of the fractionation of retina membranes is shown in Fig. 1. The ROS (rod outer segment) membranes were isolated by the procedure of McConnell (1965) with slight modifications. In the sucrose density gradient that we used the ROS membranes floated as two well defined red colored layers, at the junction between 0.77 and 0.94 M sucrose and between 0.94 and 1.10 M sucrose. The proteins of these two membrane layers showed similar patterns by sodium dodecyl-sulfate polyacrylamide gel electrophoresis, being rhodopsin its major component. The retina membranes that did not sediment with the crude ROS fraction, namely ROS free membranes, were subfractionated by centrifugation in sucrose density gradients into subfractions Pla,Plb,P2,P3 and P4. The ROS and Plb layers were red colored while the sediment at the bottom of the tube was brownish. 

Slurrying, starch isolation, 674-676 Small-granule starches, centrifugation, 676 Smell chemicals, see Aroma compounds Smoke, interfacial properties, 609 (table) Sodium borohydride, 717 Sodium dodecyl sulfate, in SDS-PAGE. see Polyacrylamide gel electrophoresis Sodium thiosulfate, standardization, 519-520... 

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