native gel electrophoreis and SDS-PAGE

[sarah_121]

I just needed a bit of help with this question:

A sample of protein was exambined by both native gel electrophoresis and SDS-PAGE.

For the native gel electrophoresis, it resulted in one band at 150kDa, and for the SDS PAGE there was 2 bands: one at 70kDa and another at 40kDa.

The questions are:
i. what is the apparent molecular weight of the protein?
ii. what is the likely subunit composition of the purified protein? How many subunits and what size could they be?

Thanks!

[deadbudgy]

I think you have answered your own question. The molecular weight of the protein, as estimated by this experiment, is going to be approximately 150kDa. It appears that your protein may have three subunits, 1x70kDa and 2x40kDa. Be aware that estimating mw from native PAGE can be problematic and perhaps the difference represents experimental error.