Cholecystokinin CCK was the first hormone that was demonstra

Cholecystokinin (CCK) was the first hormone that was demonstrated to affect appetite. It is released from the duodenum and jejunum upon consumption of food, and it acts to create a feeling of \"fullness\". After its discovery, it was hoped that CCK could be used somehow as an anti-obesity drug. However, it appears that decreases in meal size caused by CCK are offset by increases in meal frequency The active hormones are derived by cleavage of the cholecystokinin precursor protein into smaller peptides. In humans, CCK8 is an octapeptide with the sequence DYMGWMDF-NH2. Notice that the peptide is modified: the last residue does not have a free carboxyl group. Instead, it has been amidated (see figure below) DYMGWMDF-C O- NH2 immature CCK8 mature CCK8

Solution

DYMGWMDF

G is Non polar or hydrophobic

DD - are positively charged

YWF are polar uncharged

MM are polar charged