Cysteines introduced into extracellular loops 1 and 4 of human P-glycoprotein that are close only in the open conformation spontaneously form a disulfide bond that inhibits drug efflux and ATPase activity. Loo TW, Clarke DM. J Biol Chem. 2014 Sep 5;289(36):24749-58. Read Identification of the distance between the homologous halves of P-glycoprotein that triggers the high/low ATPase activity switch. Loo TW, Clarke DM. J Biol Chem. 2014 Mar 21;289(12):8484-92. Read The cystic fibrosis V232D mutation inhibits CFTR maturation by disrupting a hydrophobic pocket rather than formation of aberrant interhelical hydrogen bonds. Loo TW, Clarke DM. Biochem Pharmacol. 2014 Mar 1;88(1):46-57. Read