Transporter Drug Discovery In Vitro Assay

The transporter is a membrane protein that helps ions, tiny molecules, and macromolecules like proteins travel across a biological membrane. By facilitated diffusion or active transport, the transporters may aid in the movement of molecules. The two primary categories of proteins involved in such transport are channel proteins and carrier proteins. In humans, atypical SLCs and solute carriers are secondary active or facilitative transporters. Transporters control the cellular influx and outflow of ions, nutrients, and medicines.

Fig.1. Membrane transport protein. (Wikipedia)

Membrane Transport Proteins

When compared to channels or pores, transporters behave significantly differently. Transporters transport solutes across the membrane in discrete quanta rather than allowing a relatively fast ow of solutes through the membrane. They do this by binding to the solute on one side of the membrane, changing conformation to bring the solute to the other side of the membrane, and then releasing the solute.

• Active transport
  Moving a material through a membrane against its concentration gradient is known as active transport. Usually, this is done to build up large amounts of chemicals that a cell need, such glucose or amino acids. Primary active transport is a term used to describe a process that employs chemical energy, such as adenosine triphosphate (ATP). Secondary active transport does not use energy produced by the cell and instead uses an electrochemical gradient. Unlike channel proteins, which can only passively move materials through membranes, carrier proteins can move ions and molecules by secondary active transport or passively through assisted diffusion. To transport particles from low- to high-concentration regions, a carrier protein is necessary.
• Facilitated diffusion
  Facilitated diffusion is the energy-free movement of molecules or ions across a biological membrane by means of certain transport proteins. Active transport uses a somewhat different class of carrier proteins than assisted diffusion. Even though they are gated transmembrane channels, which do not internally translocate or require ATP to function, they are nonetheless transmembrane carrier proteins. Without requiring ATP, the substrate is released into the cell after being taken in by one side of the gated carrier.

Pharmacology

Membrane transport proteins catalyze the translocation of ions, nutrients, neurotransmitters, and a variety of medications across biological membranes, which is a crucial activity in every live cell. Their function has been linked to a variety of diseases, including autism, epilepsy, migraine, depression, drug addiction, and cystic fibrosis, and they play a key part in the success or failure of cancer treatment. As a result, they are of key medical/pharmacological interest for drug development and delivery with a specific target.