Protein mobility

Piljic, A. and Schultz, C. (2006). Annexin A4 self-association modulates general membrane protein mobility in living cells. Mol. Biol. Cell 17, 3318-28. 

Karpowich, N. K., Huang, H. H., Smith, P. C. and Hunt, J. F. (2003). Crystal structures of the BtuF periplasmic-binding protein for vitamin B12 suggest a functionally important reduction in protein mobility upon ligand binding, J. Biol. Chem., 278, 8429-8434. 

The set of buffers compiled by McLellan provides the simplest way to carry out the electrophoresis of proteins in their native state.25 McLellan s buffers range from pH 3.8 to pH 10.2, all with relatively low conductivity (Table 8.1). By using different buffers from the set it is possible to compare the effect of pH changes on protein mobility while maintaining similar electrical conditions. This is demonstrated... 

Figure 8.5 Effect of pH on protein mobility. Hemoglobin A (pi 7.1) and Hemoglobin C (pi 7.4) were electrophoresed in eight of the McLellan native, continuous buffer systems (Table 8.1). The diagram is drawn to scale. Migration is from top to bottom as shown by the vertical arrows. Bands marked A or C indicate the positions of the two hemoglobin variants in each gel representation. The polarities of the voltages applied to the electrophoresis cell are indicated by + and - signs above and below the vertical arrows. Run times are shown below the arrows. Note the polarity change between the gel at pH 7.4 and the one at pH 8.2. This reflects the pis of the two proteins (and was accomplished by reversing the leads of the electrophoresis cell at the power supply).

Measurement of Protein Mobility Within Cell Membranes... 

Osterberg, F., Morris, G.M., Sanner, M.F., Olson, A.J. and Goodsell, D.S. (2002) Automated docking to multiple target structures incorporation of protein mobility and structural water heterogeneity inAutoDock. Proteins, 46, 34—40. 

The interactions can be studied when both the analyte and the affinity molecule are in free solution. In most polysaccharide-protein interaction studies, the protein is injected as a substrate to the capillary and the polysaccharide is in the running buffer. The change in migration of the protein due to the binding to the polysaccharide is observed, and this allows the affinity of interaction to be determined. However, a mobility change of the polysaccharide might also be observed in cases where little or no change in protein mobility is observed. 

Under this condition of reduced solution amounts, the amount of the SDS ions in the electrolyte solution decreases with time and protein mobility during electrophoresis becomes gradually reduced if the applied potential is maintained at a constant voltage. Applying the condition of constant current, the voltage is increased to maintain the separation mobility in the latter half of the process. 

N-NMR relaxation 49 protein mobility and 46 -49 rotation of amino acid side chains and 47, 48... 

Muntz, K., Belozersky, M.A., Dunaevsky, Y.E., Schlereth, A., and Tiedemann, J. 2001. Stored proteinases and the initiation of storage protein mobilization in seeds during germination and seedling growth. J Exp Bot 52(362) 1741-1752. 

Protein mobility and aggregation are inherent problems in the in situ STM and AFM characterization. This can, however, also be turned to the better and brought to open other new perspectives for mapping of molecular and collective protein dynamics such as phase transitions, heterophase fluctuations etc. 

A. Relationship of Protein Mobility to Protein Mass and Valence... 

Resolution is enhanced by titration across a common pKa region or a region where either charge or side-chain modification has occurred that will emphasize charge difference. The resolution is increased when the EOF and mobility are matched. Protein mobility changes in a sigmoidal fashion as a function of pH. 

In the last years the application of two-dimensional electrophoresis (2-DE) has often been declared outdated and a new century of gel-free proteomics was announced. Nevertheless, 2-DE is still the method of choice when analyzing complex protein mixtures. With a separation of10 000 proteins, 2-DE gives access to high-resolution proteome analysis. Continuous development has consolidated 2-DE application in proteomics, where the introduction of difference gel electrophoresis (DICE) is the latest improvement. DICE is based on fluorescently tagging all proteins in each sample with one set of matched fluorescent dyes designed to minimally interfere with protein mobility during 2-DE. 

One of the most important of these applications is determining the molecular weights of native proteins. Under restrictive electrophoresis conditions, that is where the gel porosity affects protein mobility, there is a linear relationship between... 

---