ATP hydrolysis by a CFTR domain: pharmacology and effects of G551D mutation.

Published

Journal Article

Residues 417-830 of the cystic fibrosis transmembrane conductance regulator (CFTR) were expressed as a glutathione-S-transferase fusion protein. This fusion protein, NBD1/R/GST, contains the regulatory and first nucleotide binding domains of CFTR. NBD1/R/GST hydrolyzed ATP with a K(M) (60 microM) and V(max) (330 nmol/min/mg) that differed from those reported for CFTR and for a peptide containing CFTR residues 433-589. The ATPase inhibitor profile of NBD1/R/GST indicates that CFTR resembles P-glycoprotein with respect to the NBD1 ATPase catalytic mechanism. ATP hydrolysis by NBD1/R/GST was unaffected by genistein, glybenclamide, and other agents known to affect CFTR's chloride channel function, suggesting that these agents do not act by directly influencing the ATPase function of NBD1. The disease-causing mutation, G551D, reduced ATP hydrolysis by NBD1/R/GST by increasing the K(M) for ATP fourfold. This suggests that when G551D occurs in patients with cystic fibrosis, it affects CFTR function by reducing the affinity of NBD1 for ATP.

Full Text

Duke Authors

Cited Authors

  • Howell, LD; Borchardt, R; Cohn, JA

Published Date

  • May 10, 2000

Published In

Volume / Issue

  • 271 / 2

Start / End Page

  • 518 - 525

PubMed ID

  • 10799328

Pubmed Central ID

  • 10799328

International Standard Serial Number (ISSN)

  • 0006-291X

Digital Object Identifier (DOI)

  • 10.1006/bbrc.2000.2659

Language

  • eng

Conference Location

  • United States