Protein electrophoretic behavior

Haggerty, L Lenhoff, AM, Relation of Protein Electrostatics Computations to Ion-Exchange and Electrophoretic Behavior, Journal of Physical Chemistry 95, 1472, 1991. 

The literature is devoid of any studies on the electrophoretic behavior of lignins. However, due to the presence of at least one phenolic hydroxyl group per lignin building unit, it appeared that such an investigation would be feasible. Moreover, due to the success of applying electrophoretic methods to the characterization and fractionation of proteins, a study as to the possible availability of the method to lignins was undertaken in this laboratory. 

From the experiments it is clear that poly electrolyte is adsorbed on the surface of the black lipid film. This applies both to the experiments with gelatin and bovine serum albumin, which gave no decrease of film resistance, and to the experiments with bovine erythrocyte ghost protein and polyphosphate. The adsorption of protein on the phospholipid-water interface may be controlled independently by investigating the electrophoretic behavior of emulsion droplets, stabilized by phospholipid, in a protein solution, as a function of pH. In this way Haydon (3) established protein adsorption on the phospholipid-water interface. If the high resistance (107 ohms per sq. cm.) of black lipid films is to be ascribed to the continuous layer of hydrocarbon chains in the interior of the film, as is generally done, an increase in film conductivity is not expected from adsorption without penetration. 

Bovine Serum Albumin. Since Polis et al. (1950) crystallized bovine serum albumin from whey and demonstrated that it was identical in all properties investigated to blood serum albumin, except in its electrophoretic behavior at pH 4.0, very little work has been done on this protein as isolated from milk. However, much work has been done on the protein isolated from bovine blood plasma. There is considerable evidence that serum albumin is heterogeneous. For example, Spencer and King (1971) have demonstrated several protein bands by electrophoretic focusing, with two major isoelectric components differing by one unit of charge. The chemical nature of this difference is not known. 

The purification of glutamine cyclotransferase from papaya latex has been carried out by Messer and Ottesen (116). A batch procedure was used for the removal of impurities by passage of a papaya latex extract through a thin layer of carboxymethyl-Sephadex the active protein was separated by selective elution. Additional purification was achieved by chromatography on a column of carboxymethyl-Sephadex and by gel filtration on Sephadex G-100. The purified enzyme was homogeneous by the criteria of paper electrophoresis, ultracentrifugation, and gel filtration on Sephadex G-100 columns and chromatography on carboxy-methyl- or DEAE-Sephadex. The electrophoretic behavior of the enzyme indicates that it is a basic protein with an isoelectric point near... 

Hemoglobin A (the major, normal form in humans) has an isoelectric point of pH 6.9. The variant hemoglobin M has a glutamate residue in place of the normal valine at position 67 of the a chain. What effect will this substitution have on the electrophoretic behavior of the protein at pH 7.5 ... 

Corticelli, B., Deiana, S. (1957). Electrophoretic behavior of serous and plasmatic proteins of the rabbit poisoned by Ferula communis. Boll. Soc. Ital. Biol. Sper. 33(5) 625-8. 

One point of interest resulting from these experiments is the difference in the electrophoretic behavior of Ai, A2, and A3. In general, as the pH of a protein solution is increased, various groups within the protein molecule... 

Further evidence for the occurrence of a diester linkage in this protein is reflected in the electrophoretic behavior. Pepsin still moves anodically in 0.1 N hydrochloric acid, pH 1.08. On the other hand, the phosphorus-free pepsin is positively charged at this pH. It has an isoelectric pH of 1.7. As shown in Fig. 6, the mobilities of these two proteins differ by a... 

Polymorphism of CuZnSOD has been found in human and animal populations. A variant of CuZnSOD (SOD-2 an unfortunate designation because SOD-2 is used nowadays for MnSOD, or SOD-A as opposed to the prevalent SOD-A ) has been shown to occur in a small fraction of the Scandinavian population and to be present in the Mormons (Utah, USA) of Scandinavian origin, but it is also present in Central Africa, Italy, and Iraq. The variant protein has a different electrophoretic behavior and shghtly lower specific activity [102,103]. 

N. Humbert, A. Zocchi, T. R. Ward, Electrophoretic behavior of streptavidin complexed to a biotinylated probe a functional screening assay for biotin-binding proteins. Electrophoresis, 2005, 26, 47-52. 

Mosher RA, Dewey D, Thormaim W, SavUle DA, Bier M. Computer simulation and experimental validation of the electrophoretic behavior of proteins. AnoZ Chem 1989 61 362-6. 

This material was identified as the protein YPg (i) by labeling with ( 3H)amino acids (for example, lys, arg, leu, or tyr) (ii) by its sensitivity to pronase, protease K, or amino peptidase (iii) by its electrophoretic behavior on paper or in polyacrylamide gels (Figure 2) and (iv) by the fact that it is insoluble in chlorofom/ methanol or acetone, and only partially soluble in 5-20% trichloroacetic acid (for details, see ref. 8, 11, 12, I3). Attempts to remove the protein from the ENA prior to ENase T2 digestion by various physical methods failed (l1). Unambiguous proof that YPg was covalently linked to virion ENA came from the isolation of a nucleotidyl-protein (VPg-pUp) and a nonanucleotidyl-protein (VPg-pU-U-A-A-A-A-C-A-Gp) after digestion of virion ENA with ENase T2 and ENase T1, respectively (II, I3, I4). 

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