Question

I need some help getting going on this.

Name: So here is a problem for you a) You isolate the proteins from an intact membrane and run these on a gel. You find proteins of molecular weights 200kDa (kiloDaltons are used to express molecular weights), 150kDa, 60kDa and 30kDa. b) After washing the membranes with a dilute salt solution, you run the proteins on a gel and find protein bands corresponding to molecular weights 200kDa, 150 kDa and 30 kDa. dl You treat another preparation of the same kind of membrane with phospholipase C and dilute salt. You run the proteins on a gel and find bands corresponding to 200kDa and 150 kDa. Which proteins are likely to be: Integral Peripheral GPI-anchored? 4. Hydronathuunl

Answer 1

1. Intergal membrane protein - A

Intergal membrane protein are tightly attached to the membrane.This proteins are separated by using heavy treatments like detergents, non polar sovents etc.

2. Peripheral protein - B

Peripheral protein temporarily attached to the membrane by using hydrophobic, electrostatic, and other non-covalent interactions. It dissociate a protein easily by adding high salt concentrations.

3. GPI anchored - C

Surface proteins of eukaryotic cells are tethered to the membrane by a GPI-anchor which is enzymatically cleavable by phospholipase C.