Question

The integral protein, when removed from plasma membrane, will show which one of the following properties?

• A. Soluble in aqueous solution
• B. Insoluble in aqueous solution
• C. Formation of bilayer in H${}_2$O
• D. Solubility will differ from protein to protein

Answer 1

Answer: (B)

Insoluble in aqueous solution

• The proteins associated with plasmalemma may be intrinsic or integral membrane protein and extrinsic or peripheral membrane protein.
• The peripheral proteins are associated with the membrane by weak electrostatic bonds. Peripheral proteins can be easily solubilized by extraction with aqueous solutions of high salt or alkaline pH.
• The integral proteins are not easily extracted from the membrane because of their high degree of insolubility in water and non-covalent bonds. They are embedded deep within the membrane lipid bilayer.