The problem is to explain why each additive gives rise to the distribution of the protein (RMAS) as shown in the Western blow below:
In each case, the homogenates were subjected to high-speed centrifugation and the supernatant/pellet fractions were resolved separately by SDS-polyacrylamide gel electrophoresis. The gels were blotted and probed with an antibody raised against RMAS.
I am specifically stuck on explaining the effect of the 0.5M urea vs 5M urea on the soluble and insoluble proteins represented by the pellet and supernatant respectively. My thinking is that at low urea concentrations (0.5M) the pellet protein is destabilised by urea and solubility increases showing a band. However, soluble proteins are denatured and show no band. However, at 5M urea, the pellet proteins are reversibly soluble and therefore do not show as a band whereas the soluble proteins are OK and so show a 'normal' band. I don't know if this is the right explanation, so could someone please explain it to me??