In the schematic drawing below, a protein is present on one side of a membrane in a high-enough quantity to induce curvature in this region of the membrane. In each of the following scenarios, indicate whether the protein would induce positive (P) or negative (N) curvature in the membrane. Your answer would be a three-letter string composed of letters P and N only, e.g. PPP.

( ) The protein inserts a hydrophobic domain into the membrane leaflet that is facing it.
( ) The protein is a phospholipase that cleaves the head group in specific phospholipids.
( ) The protein binds cooperatively to multiple phospholipids with very large head groups.

Question

In the schematic drawing below, a protein is present on one side of a membrane in a high-enough quantity to induce curvature in this region of the membrane. In each of the following scenarios, indicate whether the protein would induce positive (P) or negative (N) curvature in the membrane. Your answer would be a three-letter string composed of letters P and N only, e.g. PPP.
  
( )	The protein inserts a hydrophobic domain into the membrane leaflet that is facing it.
( )	The protein is a phospholipase that cleaves the head group in specific phospholipids.
( )	The protein binds cooperatively to multiple phospholipids with very large head groups.

Quizplus · Accepted Answer

Proteins can use various strategies to create curvature in cellular membranes: by inserting a hydrophobic domain (or attached lipid anchor), by acting as rigid scaffolds that directly deform the membrane, or by biasing the shape of phospholipids present in a particular region of the membrane (e.g. by clustering phospholipids that have large head groups).

In the Schematic Drawing Below, a Protein Is Present on One