Description
Cyclophilins are peptidyl prolyl isomerases that catalyze the cis-trans isomerization of X-Pro peptide bonds. They are highly-conserved cytoplasmic enzymes that accelerate protein folding and facilitate HIV infectivity. Cyclosporin A binds to cyclophilin and inhibits its activity. The cyclosporin A-cyclophilin complex binds to calcineurin and inhibits T-cell activation. The structure of human, recombinant cyclophilin is given by Holzman, et al