You isolate an organelle to identify the precise location of

You isolate an organelle to identify the precise location of three related proteins, p90, p70, and p30. The organelle preparation is divided in half, one half is saved as a control (as-is) sample, the other half is sonicated (bombarded with sonic energy) to lyse (open up) organelles. Each sample is then divided into three treatment group: no treatment (control), high salt (1M KCl), or protease (trypsin). After the treatments, each sample is centrifuged to produce a supernatant and pellet, and separated by SDS-PAGE. Examine the gel below and then draw the locations of p90, p70, and p30 on organelle diagram. Explain you reasoning. Make sure it is clear from the drawing whether each is a luminal protein, a peripheral, or integral membrane protein.

NOT SONICATED SONICATED S P S P S P S P S P S P P90 P30

Solution

When the control is not sonicated, all the proteins are present in the pellet. But On sonication of the control, the p90 is present in the supernatent indicating that it is an peripheral membrane protein. When the solutions is treated with 1M KCl and sonicated then all the proteins come into the supernatent. This suggest that p30 is integral membrane protein as even without sonication if appeared in supernatent on 1M KCl treatment. The p60 is luminal protein