ABCMdb

PMID: 21452853

Ohnuma S, Chufan E, Nandigama K, Jenkins LM, Durell SR, Appella E, Sauna ZE, Ambudkar SV
Inhibition of multidrug resistance-linked P-glycoprotein (ABCB1) function by 5'-fluorosulfonylbenzoyl 5'-adenosine: evidence for an ATP analogue that interacts with both drug-substrate-and nucleotide-binding sites.
Biochemistry. 2011 May 10;50(18):3724-35. Epub 2011 Apr 13., 2011-05-10 [PubMed]

Sentences

No. Mutations Sentence Comment

30 ABCB1 p.Tyr1044Ala ABCB1 p.Tyr401Ala In addition, this FSBA interaction at the TMDs does not require functional ATP sites, as the IAAP labeling in the Y401A/Y1044A double mutant lacking ATP-binding capacity is still inhibited by FSBA. Login to comment 38 ABCB1 p.Tyr401Ala High-Five insect cells (Invitrogen, Carlsbad, CA) were infected with the baculovirus carrying the human MDR1 cDNA (either wild-type or Y401A/ 1044A or the cys-less mutant where all seven native cysteine residues are replaced with alanine) with a 6X histidine tag at the C-terminal end as described previously.33 Crude membranes were prepared and stored at À70 °C as described previously.33,34 Purification and Reconstitution of P-gp. Login to comment 156 ABCB1 p.Tyr1044Ala ABCB1 p.Tyr401Ala Similar results were obtained when the mutant P-gp (Y401A/Y1044A), which lacks the capacity to bind nucleotides, was used in lieu of the wild-type protein (Figure 6D). Login to comment 188 ABCB1 p.Tyr1044Ala ABCB1 p.Tyr401Ala (B) The apparent affinity of FSBA for the substrate-binding sites of the Y401A/Y1044A mutant-P-gp, which cannot bind ATP, was estimated as described in (A). Login to comment 190 ABCB1 p.Tyr401Ala Photoaffinity labeling of wild-type (C) and Y401A/1044A mutant (D) with IAAP after the formation of FSBA-P-gp adduct. Login to comment 257 ABCB1 p.Tyr401Ala The binding of the transport substrate IAAP to wild-type P-gp or mutant Y401A/1044A (that cannot bind to ATP) is not affected by the formation of an FSBA-P-gp adduct (Figure 6C,D), suggesting that FSBA is not cross-linked to the IAAP binding site. Login to comment