OPPapers.com Essay Index >> Science >> Review Of Arginine-482 Is Not Essential For The Transport Of Antibiotics, Primary Bile Acids And Unconjugated Sterols By The Human Breast Cancer Resistance Protein (Abcg2)
We have many free term papers and essays on Review Of Arginine-482 Is Not Essential For The Transport Of Antibiotics, Primary Bile Acids And Unconjugated Sterols By The Human Breast Cancer Resistance Protein (Abcg2). We also have a wide variety of research papers and book reports available to you for free. You can browse our collection of term papers or use our search engine.
Review of Arginine-482 is not essential for the transport of antibiotics, primary
bile acids and unconjugated sterols by the human breast cancer resistance ...
Submitted by patternseed on April 5, 2006
Category: Science
Words: 1292 | Pages: 6
Views: 180
Popularity Rank: 58,650
Average Member Grade: N/A (Add a Comment / Grade this Paper)
The breast cancer resistance protein has been found to be a transporter that extrudes various anticancer drugs from cells, resulting in multi-drug resistance. Recent studies on tissue distribution of BCRP (breast cancer resistance protein) showed that the protein is expressed in the apical membrane of cells in tissues with excretory functions, such as luminal membrane of villous epithelial cells in small and large intestines, the apical pole of the trophoblast cells in the placenta, and apical membranes of capillary vessels in the blood-brain barrier, ducts and lobules of the breast. These findings are consistent with the belief that BCRP plays a role in the disposition and pharmacological activity of a broad range of compounds. Other early studies on BCRP revealed that some drug-selected mammalian cell lines expressing BCRP demonstrate resistance to cationic rhodamine 123 and anthracyclines due to the presence of a neutral G (glycine), T (threonine), S (serine) or M (methionine) residue at position 482 of BCRP while those expressing wild-type, R (with an arginine at 482), remain sensitive. In this study, investigations on sterol transport were expanded to BCRP-R in L. lactis. In addition, the specificities of BCRP-G and –R for antibiotics and primary bile acids were compared in detail to analyze the role of Arg-482 in the BCRP-mediated transport of these substrates.
To examine whether BCRP-G and –R are active as antibiotic efflux systems the interaction of BCRP with antibiotics was tested. When lactococcal cells expressing BCRP-G or –R were exposed to erythromycin, both exhibited significantly increased survival ratio (the number of colony-forming units in the presence of erythromycin / number of colony-forming units without the antibiotic) at increasing concentrations of erythromycin when compared to the non-expressing control cells. High relative resistance factors of 82 and 78 were determined for BCRP-G- and -R-expressing cells in growth...
You must Login to view the entire paper.
If you are not a member yet, Sign Up for free!