Quick Definition
What is an ABC Transporter?: ATP-binding cassette (ABC) transporters are membrane proteins that use ATP hydrolysis to actively transport substrates across cell membranes against a concentration gradient. In pharmacokinetics, ABC efflux transporters — including P-gp, BCRP, BSEP, and the MRP family — control drug absorption, distribution, and elimination by pumping drugs out of cells at key biological barriers.
Buy ABC transporter vesicle kits (HEK293-derived)
Request a quote for P-gp, BCRP, BSEP and MRP vesicle kits for in vitro DDI studies.
- P-gp (MDR1/ABCB1) vesicle kit
- BCRP (ABCG2) vesicle kit
- BSEP (ABCB11) vesicle kit
- MRP1 (ABCC1) vesicle kit
- MRP2 (ABCC2) vesicle kit
- MRP3 (ABCC3) vesicle kit
- MRP4 (ABCC4) vesicle kit
- MRP5 (ABCC5) vesicle kit
- MRP8 (ABCC11) vesicle kit
- P-gp vesicle kit with FluoPgp substrate
- Control vesicle kit (negative control)
Vesicle kits for FDA/EMA/ICH M12 transporter studies · EU stock
How do ABC transporters work?
ABC transporters have two transmembrane domains (TMDs) forming the substrate translocation pathway and two nucleotide-binding domains (NBDs) that bind and hydrolyse ATP. Transport cycle: (1) substrate binds to inward-facing TMD from cytoplasm; (2) ATP binds to both NBDs → dimerisation → TMDs shift to outward-facing conformation; (3) substrate released extracellularly; (4) ATP hydrolysis → transporter resets.
Clinical significance of ABC transporter DDIs
Most important clinical examples: P-gp inhibition by ritonavir increases digoxin AUC by 86%; dual P-gp/BCRP inhibition by eltrombopag doubles rosuvastatin exposure; BSEP inhibition by troglitazone caused fulminant hepatic failure and market withdrawal; P-gp induction by rifampicin reduces digoxin bioavailability 30–40%.
Key Facts
- ABC = ATP-Binding Cassette — named after conserved nucleotide-binding domains that hydrolyse ATP to power transport
- Human genome encodes 48 ABC transporter genes divided into 7 subfamilies (ABCA–ABCG)
- Drug-relevant efflux transporters: P-gp (ABCB1), BCRP (ABCG2), BSEP (ABCB11), MRP1-8 (ABCC1-6, ABCC10-11)
- Location determines pharmacokinetic role: intestinal epithelium (limits oral absorption), BBB (limits CNS penetration), hepatocyte canalicular membrane (biliary excretion), renal tubule (urinary excretion)
- ABC transporters work as efflux pumps: substrate binds on intracellular face → ATP hydrolysis → conformational change → substrate released extracellularly
- FDA, EMA and ICH M12 require in vitro assessment of P-gp, BCRP, BSEP, and MRP family interactions for all NMEs
Further Reading
- What is P-glycoprotein (P-gp)?
- What is BCRP?
- What is BSEP?
- What is a Vesicular Transport Assay?
- Inside-Out Vesicles Explained
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Related products & protocols: ABC transporter vesicle kits & transporter assays
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