Solution structure of the satiety factor, CART, reveals new functionality of a well-known fold

Cocaine and amphetamine regulated transcript (CART) peptide has been shown to be an anorectic peptide that inhibits both normal and starvation-induced feeding and completely blocks the feeding response induced by neuropeptide Y and regulated by leptin in the hypothalamus. The C-terminal part containing the three disulfide bridges CART(48-89) is the biologically active part of the molecule affecting food intake. The solution structure of the active part of CART has a fold equivalent to other functionally distinct small proteins. CART consists mainly of turns and loops spanned by a compact framework composed by a few small stretches of antiparallel beta -sheet common to cystine knots.