Slab gel electrophoresis of oligomeric proteins under high hydrostatic pressure. I. Description of the system and demonstration of the pressure dissociation of a dimer.
A high-pressure bomb was constructed to study the gel electrophoretic behavior of oligomeric proteins under pressure. The apparatus designed by us allows the use of a polyacrylamide slab gel with a capacity of up to 12 wells, therefore permitting the study of several samples in one experiment. The electrophoresis mobility of different single-chain proteins under pressure decreased in the same proportion and the elution pattern was similar to that of the control run at atmospheric pressure. Densitometric analysis of the gel did not show peak spread or asymmetric boundaries, indicating that their conformations were not drastically affected. On the other hand, high-pressure electrophoresis of a dimer, the tryptophan synthase beta 2 subunit, revealed the appearance of a second peak not present at atmospheric pressure. The mobility of the second peak was higher and its fraction increased by decreasing the protein concentration, indicating that the extra peak was the dissociated monomer. The separation under pressure occurs without drastic effects on the tertiary structure of the protein, which seems to furnish a method to study dissociation processes and to separate the constituent polypeptides of oligomeric complexes.
D004591:Electrophoresis, Polyacrylamide Gel / Q000379:methods*; D006874:Hydrostatic Pressure; D009211:Myoglobin / Q000032:analysis; D011506:Proteins / Q000032:analysis*; D012710:Serum Albumin, Bovine / Q000032:analysis; D014367:Tryptophan Synthase / Q000032:analysis
D009211:Myoglobin; D011506:Proteins; D012710:Serum Albumin, Bovine; D014367:Tryptophan Synthase