STRUCTURE AND FUNCTION OF MULTIDRUG TRANSPORTER PROTEINS AND MECHANISM OF RESISTANCE TO AVAILABLE CHEMOTHERAPY. - See more at: http://www.journalijar.com/article/8175/structure-and-function-of-multidrug-transporter-proteins-and-mechanism-of-resistance-to-available-chemotherapy./#sthash.Ba1u1p5q.dpuf

Simple prokaryotic cells and complex eukaryotic cells constantly monitor their environment and try to maintain the chemical homeostasis and composition inside their cells? liquid broth (cytoplasm). Cells express, on or across their lipid-bilayer membrane, various proteinaceous receptors, in order to communicate with extra-cellular matrix system by exchange of nutrients, ions, solutes and other molecules of diverse nature and polarity. Majority of compounds, including natural toxins or drugs, can move in or out of cell via passive transport depending on the permeability of membrane by either simple diffusion (through protein-lined channel), facilitated diffusion (using carrier proteins) or osmosis (through membrane) based on their small size, polarity and concentration gradient across the membrane. Whereas, the remaining category of compounds - mainly toxins, metabolites and xenobiotic - which cells sense as poisonous, harmful and unwanted is transported out of the cell through specialized membrane transporters at the expense of energy molecules, called Adenosine Tri-Phosphate (ATP), as they do not follow the normal mechanism of transport. These membrane proteins have evolved as a multidrug transporter, which belongs to the superfamily of ATP-binding cassette (ABC) transporters, are able to expel a wide range of substrates from cells assisted by ATP hydrolysis. These proteins are responsible for efflux of antimicrobials and anticancer drugs out of their target cells? membrane rendering therapy ineffective and development of resistance to available drugs. Understanding the structure, function and mechanism of these proteins holds the key to designing and develop right drug and therapy to combat the problem of drug resistance. - See more at: