Multi-Drug Resistance and Drug Metabolism

The expression of multi-drug resistance (MDR) is key in the development of therapeutic and chemotherapeutic drugs. Accessibility, solubility, clearance rate, and drug-drug interactions can mean the difference between a wonder drug and a lethal drug. The classical form of MDR hinges on P-glycoprotein (Pgp) at the cell membrane. Pgp acts as a drug efflux pump, and provides a method to rid cells of both toxic and therapeutic compounds. Sigma has a comprehensive line of substrates, enzymes, antibodies and other screening reagents.

Drug metabolizing enzymes (DMEs) are a diverse group of proteins produced in the liver that are responsible for metabolizing a vast number of xenobiotic compounds. These compounds include exogenous proteins such as steroids, pharmaceuticals drugs, and environmental pollutants. Cytochrome P450 enzymes (CYPs) are known for their ability to metabolize a large number of structurally diverse compounds.

Review Article: Multi-Drug Resistance in Cancer - Role of ABC Transporter Proteins

Pathway Slides:

• Mechanisms In Multi-drug Resistance: ABC-transporters and detoxification enzymes I hepatocytes
• ABC-ATPases as Regulatory Transporters for NHRs: chemical sensors for endogenous metabolites and xenobiotics
• Domain Organization of Bile Salt Transporter (BSEP)
• Domain Organization of Multi-drug Related Protein (MRP1)

Helpful external links
Cytochrome P450 - University of Colorado Health Sciences Center
Biocatalysis / Biodegradation Database - University of Minnesota
Cytochrome P450 Homepage