ATP-Dependent Signaling in Simulations of a Revised Model of Cystic Fibrosis Transmembrane Conductance Regulator (CFTR).

Cystic fibrosis transmembrane conductance regulator (CFTR) is a member of the ATP-binding cassette (ABC) transporter superfamily that has uniquely evolved to function as a chloride channel. It binds and hydrolyzes ATP at its nucleotide binding domains to form a pore providing a diffusive pathway within its transmembrane domains. CFTR is the only known protein from the ABC superfamily with channel activity, and its dysfunction causes the disease cystic fibrosis.

Glutathione reductase activity with an oxidized methylated glutathione analog.

The activity of glutathione reductase with an unnatural analog of oxidized glutathione was explored. The analog, L-γ-glutamyl-2-methyl-L-cysteinyl-glycine disulfide, places an additional methyl group on the alpha position of each of the central cysteine residues, which significantly increases steric bulk near the disulfide bond. Glutathione reductase was completely unable to catalyze the sulfur-sulfur bond reduction of the analog.