P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environment
P-glycoprotein (P-gp) appears to be associated within specialized raftlike membrane microdomains. The activity of P-gp is sensitive to its lipid environment, and a functional association in raft microdomains will require that P-gp retains activity in the microenvironment. Purified hamster P-gp was r...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2004-10-01
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| Series: | Journal of Lipid Research |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0022227520312657 |
| _version_ | 1818731714062581760 |
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| author | Szabolcs Modok Catherine Heyward Richard Callaghan |
| author_facet | Szabolcs Modok Catherine Heyward Richard Callaghan |
| author_sort | Szabolcs Modok |
| collection | DOAJ |
| description | P-glycoprotein (P-gp) appears to be associated within specialized raftlike membrane microdomains. The activity of P-gp is sensitive to its lipid environment, and a functional association in raft microdomains will require that P-gp retains activity in the microenvironment. Purified hamster P-gp was reconstituted in liposomes comprising sphingomyelin and cholesterol, both highly enriched in membrane microdomains and known to impart a liquid-ordered phase to bilayers. The activity of P-gp was compared with that of proteoliposomes composed of crude egg phosphatidylcholine (unsaturated) or dipalmitoyl phosphatidylcholine (saturated) in the presence or absence of cholesterol. The maximal rate of ATP hydrolysis was not significantly altered by the nature of the lipid species. However, the potencies of nicardipine and XR9576 to modulate the ATPase activity of P-gp were increased in the sphingolipid-based proteoliposomes. The drug-P-gp interaction was investigated by measurement of the rates of [3H]XR9576 association and dissociation from the transporter. The lipid environment of P-gp did not affect these kinetic parameters of drug binding.In summary, P-gp retains function in liquid-ordered cholesterol and sphingolipid model membranes in which the communication between the transmembrane and the nucleotide binding domains after drug binding to the protein is more efficient. |
| first_indexed | 2024-12-17T23:22:04Z |
| format | Article |
| id | doaj.art-21bca5ac5c8841789081db71407e2f3f |
| institution | Directory Open Access Journal |
| issn | 0022-2275 |
| language | English |
| last_indexed | 2024-12-17T23:22:04Z |
| publishDate | 2004-10-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Journal of Lipid Research |
| spelling | doaj.art-21bca5ac5c8841789081db71407e2f3f2022-12-21T21:28:51ZengElsevierJournal of Lipid Research0022-22752004-10-01451019101918P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environmentSzabolcs Modok0Catherine Heyward1Richard Callaghan2Nuffield Department of Clinical Laboratory Sciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United KingdomNuffield Department of Clinical Laboratory Sciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United KingdomNuffield Department of Clinical Laboratory Sciences, John Radcliffe Hospital, University of Oxford, Oxford OX3 9DU, United KingdomP-glycoprotein (P-gp) appears to be associated within specialized raftlike membrane microdomains. The activity of P-gp is sensitive to its lipid environment, and a functional association in raft microdomains will require that P-gp retains activity in the microenvironment. Purified hamster P-gp was reconstituted in liposomes comprising sphingomyelin and cholesterol, both highly enriched in membrane microdomains and known to impart a liquid-ordered phase to bilayers. The activity of P-gp was compared with that of proteoliposomes composed of crude egg phosphatidylcholine (unsaturated) or dipalmitoyl phosphatidylcholine (saturated) in the presence or absence of cholesterol. The maximal rate of ATP hydrolysis was not significantly altered by the nature of the lipid species. However, the potencies of nicardipine and XR9576 to modulate the ATPase activity of P-gp were increased in the sphingolipid-based proteoliposomes. The drug-P-gp interaction was investigated by measurement of the rates of [3H]XR9576 association and dissociation from the transporter. The lipid environment of P-gp did not affect these kinetic parameters of drug binding.In summary, P-gp retains function in liquid-ordered cholesterol and sphingolipid model membranes in which the communication between the transmembrane and the nucleotide binding domains after drug binding to the protein is more efficient.http://www.sciencedirect.com/science/article/pii/S0022227520312657membrane microdomainlipid raftliquid-ordered phaseATP binding cassette transporterdrug binding |
| spellingShingle | Szabolcs Modok Catherine Heyward Richard Callaghan P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environment Journal of Lipid Research membrane microdomain lipid raft liquid-ordered phase ATP binding cassette transporter drug binding |
| title | P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environment |
| title_full | P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environment |
| title_fullStr | P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environment |
| title_full_unstemmed | P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environment |
| title_short | P-glycoprotein retains function when reconstituted into a sphingolipid- and cholesterol-rich environment |
| title_sort | p glycoprotein retains function when reconstituted into a sphingolipid and cholesterol rich environment |
| topic | membrane microdomain lipid raft liquid-ordered phase ATP binding cassette transporter drug binding |
| url | http://www.sciencedirect.com/science/article/pii/S0022227520312657 |
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