The cystic fibrosis transmembrane conductance regulator. Effects of the most common cystic fibrosis-causing mutation on the secondary structure and stability of a synthetic peptide

J Biol Chem. 1992 Mar 25;267(9):5727-30.


Deletion of phenylalanine 508 (delta Phe-508) in the cystic fibrosis transmembrane conductance regulator (CFTR) protein causes approximately 70% of all cases of cystic fibrosis. This residue lies in a region of the protein that we have synthesized chemically and shown to bind adenine nucleotides (Thomas, P. J., Shenbagamurthi, P., Ysern, X., and Pedersen, P. L. (1991) Science 251, 555-557). A peptide lacking this critical residue, but otherwise corresponding to this crucial part of the protein, now also has been chemically synthesized and purified. This mutant peptide (P-66) exhibits a significant loss of beta-sheet structure as compared with the wild type peptide (P-67). Furthermore, urea denaturation of peptide structure reveals that P-66 is less stable than P-67. Although under non-denaturing conditions both peptides bind adenine nucleotides with high affinity, the loss of structural stability is reflected in the binding function of the peptides. Thus, P-67, in contrast to P-66, retains a significant capacity for nucleotide binding in 4 M urea. These results suggest a model for impaired delta Phe-508 CFTR function.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphate / metabolism
  • Amino Acid Sequence
  • Binding Sites
  • Chromosome Deletion
  • Circular Dichroism
  • Cystic Fibrosis / genetics*
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Humans
  • Membrane Proteins / chemistry
  • Membrane Proteins / genetics*
  • Membrane Proteins / metabolism
  • Models, Molecular
  • Molecular Sequence Data
  • Mutation*
  • Peptides / chemical synthesis
  • Peptides / chemistry
  • Peptides / metabolism
  • Protein Conformation


  • CFTR protein, human
  • Membrane Proteins
  • Peptides
  • Cystic Fibrosis Transmembrane Conductance Regulator
  • Adenosine Triphosphate