What energy source does P-glycoprotein (P-gp) use to pump substrates?

What energy source does P-glycoprotein (P-gp) use to pump substrates?

• A. ATP hydrolysis
• B. GTP hydrolysis
• C. Light energy
• D. Proton motive force

Answer: (A)

P-glycoprotein is an ATP-binding cassette transporter, and its activity is powered by ATP hydrolysis. The two nucleotide-binding domains bind and hydrolyze ATP, and the energy released drives conformational changes that switch the transporter from inward-facing to outward-facing, moving substrates from inside the cell to the outside. This ATP-driven cycle is a hallmark of ABC transporters. Other energy sources don’t apply here: GTP hydrolysis is used by different protein families, proton motive force powers many secondary active transporters, and light energy powers photosensitive or photo-driven pumps, not P-gp.

P-glycoprotein is an ATP-binding cassette transporter, and its activity is powered by ATP hydrolysis. The two nucleotide-binding domains bind and hydrolyze ATP, and the energy released drives conformational changes that switch the transporter from inward-facing to outward-facing, moving substrates from inside the cell to the outside. This ATP-driven cycle is a hallmark of ABC transporters. Other energy sources don’t apply here: GTP hydrolysis is used by different protein families, proton motive force powers many secondary active transporters, and light energy powers photosensitive or photo-driven pumps, not P-gp.