Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.6.3.44 (P-glycoprotein)
 13,344 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Multidrug transporters are involved in mediating the failure of chemotherapy in treating several serious diseases. The archetypal multidrug transporter P-glycoprotein (P-gp) confers resistance to a large number of chemically and functionally unrelated anti-cancer drugs by mediating efflux from cancer cells. The ability to efflux such a large number of drugs remains a biological enigma and the lack of mechanistic understanding of the translocation pathway used by P-gp prevents rational design of compounds to inhibit its function. The translocation pathway is critically dependent on ATP hydrolysis and drug interaction with P-gp is possible at one of a multitude of allosterically linked binding sites. However, aspects such as coupling stoichiometry, molecular properties of binding sites and the nature of conformational changes remain unresolved or the centre of considerable controversy. The present review attempts to utilise the available data to generate a detailed sequence of events in the translocation pathway for this dexterous protein.
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PMID:The translocation mechanism of P-glycoprotein. 1638 Jan 20

This year marks the 30th anniversary of the discovery of the multidrug resistance (MDR) ATP-binding cassette (ABC) transporter P-glycoprotein (P-gp). Since then a considerable research effort has attempted to provide a greater understanding of the biological enigma of "multidrug" efflux. Moreover, the growing correlation between P-gp expression and a negative prognosis or poor outcome for chemotherapy has sparked significant interest in the generation of inhibitors. How close are we to overcoming the unwanted actions of P-gp in resistant cancer following 30 years of research? The initial inhibitors were pre-existing clinically used compounds and exploited the broad specificity of P-gp. Unfortunately, the concentrations required to inhibit P-gp meant that these compounds generated considerable toxicity. Pharmacological investigations progressed to rational design using the 1st generation compounds as a template structure. Inherent toxicity of the drugs was reduced; however, pharmacokinetic interactions with the anticancer drugs were unsustainable. Generation of the most recent of inhibitors employed combinatorial chemistry to produce a handful of potent and selective P-gp inhibitors. Some of these drugs have progressed to clinical trials with poor results or in some cases, undisclosed progress. There remains a clear need for the generation of P-gp inhibitors and this review describes the potential for a structure-based design to facilitate this undertaking. In particular, the plethora of functional data can provide important regions on the protein that could conceivably be exploited as inhibitor targets.
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PMID:How can we best use structural information on P-glycoprotein to design inhibitors? 1720 6

Considerable research efforts have been directed towards understanding the enigma of P-glycoprotein (P-gp) in drug development and delivery. P-gp is a multi-specific drug efflux transporter that plays a significant role in governing the bioavailability of various anti-cancer drugs. Modulation of this efflux transporter by various traditional 'chemosensitisers' forms a distinctive approach in improving pharmacokinetics and conquering drug resistance. However, such inhibitors show limitations associated with their safety and unwanted pharmacokinetic drug interaction restraining their clinical applicability. To address these concerns, several research groups have used pharmaceutical excipients (functional excipients or additives) to inhibit P-gp and enhance drug permeability. This article focuses on such excipients, various co-development strategies for the formulation of cytotoxic drugs with this multi-drug resistance (MDR) reversing additives.
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PMID:Novel formulation approaches for optimising delivery of anticancer drugs based on P-glycoprotein modulation. 1964 3