Stabilizing the cystic fibrosis transmembrane conductance regulator (CFTR) by nucleotide derivative binding to promote proper folding

Abstract

Seventy percent of people who suffer from cystic fibrosis have a cystic fibrosis transmembrane conductance regulator gene on chromosome 7 that contains a three base-pair deletion of phenylalanine at position 508, in a nucleotide binding domain called NBD1. Nucleotide binding domain one (wild-type) was expressed in protein aggregates, or inclusion bodies, from a plasmid in Escherichia coli. It was then purified on a nickel histidine-binding column and refolded. A fluorescence emission spectra wavelength scan was run on the protein that yielded a []max of 330nm for the native state of NBD1 and a []max of 346nm for the denatured state. The biggest difference between the two curves was at 225nm so this wavelength was chosen to follow unfolding. Monitoring the denaturation of NBD1 with fluorescence at this wavelength will give a characteristic curve that can be used for comparison with binding ligands to the mutant phenylalanine 508 deficient form in order to find any stabilizing effects that promote proper folding.