S-decyl-glutathione nonspecifically stimulates the ATPase activity of the nucleotide-binding domains of the human multidrug resistance-associated protein, MRP1 (ABCC1).
The human multidrug resistance-associated protein(MRP1) is an ATP-dependent efflux pump that transports anionic conjugates, and hydrophobic compounds in a glutathione dependent manner. Similar to the other, well-characterized multidrug transporter P-gp, MRP1 comprises two nucleotide-binding domains (NBDs) in addition to transmembrane domains. However, whereas the NBDs of P-gp have been shown to be functionally equivalent, those of MRP1 differ significantly. The isolated NBDs of MRP1 have been characterized in Escherichia coli as fusions with either the glutathione-S-transferase (GST) or the maltose-binding domain (MBP). The nonfused NBD1 was obtained by cleavage of the fusion protein with thrombin. The GST-fused forms of NBD1 and NBD2 hydrolyzed ATP with an apparent K(m) of 340 microm and a V(max) of 6.0 nmol P(I) x mg-1 x min-1, and a K(m) of 910 microm ATP and a V(max) of 7.5 nmol P(I) x mg-1 x min-1, respectively. Remarkably, S-decyl-glutathione, a conjugate specifically transported by MRP1 and MRP2, was able to stimulate the ATPase activities of the isolated NBDs more than 2-fold in a concentration-dependent manner. However,the stimulation of the ATPase activity was found to coincide with the formation of micelles by S-decyl-glutathione. Equivalent stimulation of ATPase activity could be obtained by surfactants with similar critical micelle concentrations.
Cool
Robbert H
RH
Department of Microbiology, Groningen Biomolecular Sciences and Biotechnology Institute, University of Groningen, Haren, The Netherlands. r.h.cool@farm.rug.nl
Veenstra
Marloes K
MK
van Klompenburg
Wim
W
Heyne
René I R
RI
Müller
Michael
M
de Vries
Elisabeth G E
EG
van Veen
Hendrik W
HW
Konings
Wil N
WN
D018528:ATP-Binding Cassette Transporters / Q000187:drug effects* / Q000378:metabolism; D000251:Adenosine Triphosphatases / Q000187:drug effects* / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism*; D001665:Binding Sites; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D005978:Glutathione / Q000031:analogs & derivatives / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D008823:Micelles; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000737:chemistry / Q000187:drug effects* / Q000235:genetics; D010446:Peptide Fragments / Q000187:drug effects / Q000378:metabolism; D017434:Protein Structure, Tertiary / Q000187:drug effects; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D013501:Surface-Active Agents / Q000494:pharmacology*
D018528:ATP-Binding Cassette Transporters; D000251:Adenosine Triphosphatases; D000255:Adenosine Triphosphate; D005978:Glutathione; D008823:Micelles; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D010446:Peptide Fragments; D011993:Recombinant Fusion Proteins; D013501:Surface-Active Agents; C465222:S-decylglutathione; C421109:multidrug resistance-associated protein 1