ABCB1 p.Phe957Cys
| Predicted by SNAP2: | A: N (53%), C: N (66%), D: D (80%), E: D (71%), G: D (66%), H: D (66%), I: N (57%), K: D (80%), L: N (61%), M: N (72%), N: D (71%), P: D (80%), Q: D (66%), R: D (75%), S: D (53%), T: D (59%), V: N (53%), W: D (66%), Y: N (82%), |
| Predicted by PROVEAN: | A: D, C: D, D: D, E: D, G: D, H: D, I: D, K: D, L: D, M: D, N: D, P: D, Q: D, R: D, S: D, T: D, V: D, W: D, Y: N, |
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[hide] Identification of residues in the drug-binding dom... J Biol Chem. 1999 Dec 10;274(50):35388-92. Loo TW, Clarke DM
Identification of residues in the drug-binding domain of human P-glycoprotein. Analysis of transmembrane segment 11 by cysteine-scanning mutagenesis and inhibition by dibromobimane.
J Biol Chem. 1999 Dec 10;274(50):35388-92., 1999-12-10 [PMID:10585407]
Abstract [show]
The drug-binding domain of the human multidrug resistance P-glycoprotein (P-gp) probably consists of residues from multiple transmembrane (TM) segments. In this study, we tested whether the amino acids in TM11 participate in binding drug substrates. Each residue in TM11 was initially altered by site-directed mutagenesis and assayed for drug-stimulated ATPase activity in the presence of verapamil, vinblastine, or colchicine. Mutants G939V, F942A, T945A, Q946A, A947L, Y953A, A954L, and G955V had altered drug-stimulated ATPase activities. Direct evidence for binding of drug substrate was then determined by cysteine-scanning mutagenesis of the residues in TM11 and inhibition of drug-stimulated ATPase activity by dibromobimane, a thiol-reactive substrate. Dibromobimane inhibited the drug-stimulated ATPase activities of two mutants, F942C and T945C, by more than 75%. These results suggest that residues Phe(942) and Thr(945) in TM11, together with residues previously identified in TM6 (Leu(339) and Ala(342)) and TM12 (Leu(975), Val(982), and Ala(985)) (Loo, T. W., and Clarke, D. M. (1997) J. Biol. Chem. 272, 31945-31948) form part of the drug-binding domain of P-gp.
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No. Sentence Comment
111 All the mutants, except F957C, yielded the mature 170-kDa protein as the major product (data not shown).
X
ABCB1 p.Phe957Cys 10585407:111:24
status: NEW112 Mutant F957C may be unstable and susceptible to proteolytic digestion.
X
ABCB1 p.Phe957Cys 10585407:112:7
status: NEW113 Immunoblots of cell extracts of HEK 293 transfected with mutant F957C showed the presence of only degradation products (data not shown).
X
ABCB1 p.Phe957Cys 10585407:113:64
status: NEW