Isoelectric Focusing of Plant Plasma Membrane Proteins

Isoelectric focusing.

Isoelectric focusing of proteins in the native and denatured states. Anomalous behaviour of plasma albumin.

1. An analytical technique of isoelectric focusing in thin layers of polyacrylamide gel has been used to determine the isoelectric point, pI, of several proteins in the presence and in the absence of concentrated urea. 2. The presence of urea did not greatly affect pI except for bovine plasma albumin, where an increase of approx. 1pH unit was found. 3. Evidence is presented that this change in ...

Isoelectric focusing and crossed immunoelectrophoresis of heme proteins in the Escherichia coli cytoplasmic membrane.

Isoelectric focusing (IEF), agarose electrophoresis, and crossed immunoelectrophoresis (CIE) were used to resolve the heme-containing proteins of the Escherichia coli cytoplasmic membrane after solubilization by Triton X-100. Two bands in IEF stained for heme with pI values of 4.7 and 5.3. One of the bands, with an isoelectric point of pH 5.3, was present only when the cells were grown to late ...

Separation and Concentration of Proteins by Isoelectric Focusing without Carrier Ampholytes in a Nitrocellulose Membrane

This paper reports a simple isoelectric focusing (IEF) technique without carrier ampholytes to generate stable pH gradients in a nitrocellulose membrane for the fabrication of paper-based analytical devices suitable for complex biological samples. To design the custom-built IEF apparatus, silver-coated copper wire electrodes were employed; the distance between anode and cathode was 8 mm. Concen...

Isoelectric focusing of proteins in rewetted ultrathin polyacrylamide gel layers.

Ultrathin layers of polyacrylamide gel bound to glass can be washed, air-dried, and stored for at least 1 year before rewetting in ampholyte solutions for isoelectric focusing. Short-term drying affects neither fluorescent banding of the ampholytes (not evident in conventional gels) nor resolution of complex protein mixtures while prolonged storage seems to have no deleterious effects. Layers a...