Proteins by electrophoresis

Analyze interacting proteins by electrophoresis, Western blotting, and mass spectrometry. 

Bergstrom, J. et al. (1998) Identification of low abundance proteins by electrophoresis and MALDI-TOF MS. Poster available at www.glycobiology.med.gu.se. 

Electrophoresis has also been employed to separate neomycin from analytically-interfering substances such as proteins. Hence Brammer and Hemsonl82 have determined the neomycin content of blood serum. Neomycin was separated from the serum proteins by electrophoresis on cellulose acetate and assayed colorimetrically following elution from the support. 

EL Le Blanc, RJ Le Blanc. Separation of cod (Gadus morhus) fillet proteins by electrophoresis and HPLC after various frozen storage treatments. J Food Sci 54 827-833, 1989. 

PROBLEM 16.33 Consider the separation of proteins by electrophoresis in the presence of an H2P04- -HP042 buffer. If you want to increase the rate at which the proteins migrate toward the negative electrode, should you increase or decrease the concentration ratio [HP042-]/[H2P04-] Explain. 

In the separation of proteins by electrophoresis, the sample is submitted to an electrical field, causing the electrically charged proteins to move in the direction of the applied current. If the experiment is carried out in solution (free electrophoresis) and the proteins have different charge densities, they will move with different velocities, allowing their separation. In practice, the process is normally carried out in a gel matrix, instead of in solution, and the gel can act not only as an inert support for the electrophoresis buffer, but also, if desired, as an active material that interacts with the proteins. 

In an experiment done to separate proteins by electrophoresis at 20°C, the voltage is switched on at time t = 0. At what time does serum albumin, for which D = 5.94xl0 7 cm2/s and MW = 66,000, reach 99% of its terminal (steady-state) average velocity (See Exercises 3.1 and 3.2.)... 

The ability to separate nucleic acids and proteins by electrophoresis has enabled great advances in the emerging fields of genomics and proteomics, which have... 

Laurell, C. B. (1966) Quartbtative estimabon of proteins by electrophoresis in agarose gel containing anubodies. AtuU. Biochem. 15, 45-52. 

Vesterberg O, Acevedo F, Bayard C. Sensitive quantification of proteins by electrophoresis in gels by use of chemiluminescence. Electrophoresis 1995 16 1390-93. 

Separate proteins by electrophoresis on 12.5% polyacrylamide gel, according to the method of Laemmli (1970). See also Table 16.3. 

Since 1905 when Hardy (H4) first observed separation of serum proteins by electrophoresis, there have been repeated suggestions that the plasma proteins are not independent components in vivo that there exist molecules... 

H2. Hardwioke, J., The estimation of serum proteins by electrophoresis on filter paper. Biochem. J. 67, 166-177 (1954). 

Extracts of the R and S biotypes of Eleusine were fractionated by stepwise increases in polyethylene glycol concentration and the various fractions were monitored for the presence of tubulin and other proteins by electrophoresis and Western blotting. By making small increases in PEG concentration, one fraction contained virtually all the recognizable tubulin and was > 85% pure as determined by Coomassie blue staining of denaturing gels (23, 24). This is comparable in purity to the protocols of Morejohn gi al- (25), but is a much faster method and allows... 

The movement of soil colloidal particles was the first description of electrophoresis as early as 1809. However, Arne Tiselius ( 1937) was the first to construct a successful instrument useful for the separation of serum protein by electrophoresis using the boundary separation principle. Because of the clinical significance of this type of separation, many improvements and refinements followed, such as utilizing paper, cellulose acetate, gel, and more recently capillaries in order to speed up and better separate (into distinct zones) the different proteins. The electric current can be utilized in the clinical applications to accomplish not just separation but other tasks ... 

The 105,000 g supernatant which was obtained from 11-day chick embryos after homogenization contains vegetalizing and some neuralizing factor in a masked form. The factor can be partially activated when the nucleic acids and acidic mucopolysaccharides are separated from the proteins by electrophoresis (Born et al, 1969). When the supernatant is treated with phenol the active factor can be isolated from the phenol layer (Tiedemann et al., 1969b). 

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