Membrane protein X can be extracted from broken erythrocyte membranes by adding
ID: 67172 • Letter: M
Question
Membrane protein X can be extracted from broken erythrocyte membranes by adding a concentrated salt solution, and it can also be cleaved into fragments by proteolytic enzymes. Treatment of intact erythrocytes with proteolytic enzymes prior to breaking the membrane and extracting the membrane components yields intact protein X. However, treatment of erthytocytes with proteolytic enzymes after breaking the membrane and extracting the membrane components yields extensively fragmented protein X. Do the properties of protein X resemble those of an integral or peripheral membrane protein? What do these observations indicate about the location of protein X in the plasma membrane (i.e, found in both leaves of the membrane? found on particular side? Explain your reasoning.
Explanation / Answer
The properties of protein X resemble those of integral membrane protein. Since being an integral membrane protein, it spans the lipid bilayer. So, treatment with proteolytic enzymes without breaking the membrane works to yield the intact protein.