Drug Transport and Membrane Transport Proteins

Abstract

In order to exert their intended therapeutic goal, drugs need to cross epithelial barriers to reach their site of action. Transport proteins have critical physiological roles in nutrient absorption and transport of endogenous compounds. These systems can serve as useful pharmacological targets and may be utilized as a mechanism to increase drug absorption. However, there is little understanding of these proteins at the molecular level due to their resistance to crystallization. Numerous efforts have been made to characterize the P-glycoprotein efflux pump, the peptide transporter (PepT1), and the apical sodium dependent transporter (ASBT), which are important not only for their native transporter function but also as drug targets to increase absorption and bioactivity. In vitro and computational approaches have been applied to gain some insight into these transporters and their substrate specificities. This represents an opportunity for optimizing molecules as substrates for solute transporters and providing a further screening system for drug discovery. This chapter will demonstrates that future growth in knowledge of transporter function will be lead by integrated in vitro and in silico approaches. Keywords: ASBT; bile acid; bioavailability; epithelia; MDR; multidrug resistance; Pep T1; peptide transport; P-glycoprotein; transport