Briefly introduce the molecular characteristics and biological functions of CCK

Posted by Lisa Clara on December 21st, 2019

Cholecystokinin (CCK), also known as pancreozymin, is a gastrointestinal peptide hormone that can cause gallbladder contraction and promote secretion of various enzymes in pancreatic juice. CCK is widely present in the digestive system, central and peripheral nervous systems, and has an inhibitory effect on animal feeding. CholecystokininAreceptor (CCKAR) plays a regulatory role in animal feed intake, satiety, and obesity. This article briefly introduces the molecular characteristics and biological functions of CCK.

Molecular characteristics of CCK

CCK is a general term for a class of molecules of different lengths. Various forms of CCK are formed by post-translational processing of the original CCK, and the mRNA sequence encoding the original CCK is analyzed. The pre-CCK mRNA of human, pig, and rat all consists of 245 nucleotides, encoding a 115-amino acid CCK-prototype, which contains all currently known CCK amino acid sequences.The main molecular form is CCK-8 , CCK-4, CCK-33, CCK-39, and CCK-58. CCK C-terminal sulfide octapeptide Asp-Tyr (S03H) -MET-GLY-Try-Met-Asp-PheNH2 exists in all species and is recognized as the basic unit of peripheral and central biological activity of CCK. The tyrosine at position 7 exists in sulfurized form, which is necessary to maintain the biological activity of CCK.

Biological functions of CCK

CCK is widely distributed and has a variety of biological functions.The most important function is to contract the gallbladder and promote the secretion of pancreatic enzymes.At the same time, as a satiety factor, it has the function of inhibiting animal feeding and can reduce a variety of animals such as rabbits, chickens, Feed intake of pigs and sheep. Endogenous CCK is a basic hormone that regulates gallbladder contraction and pancreatic enzyme secretion after ingestion. CCK plays a key role in the secretion of pancreatic polypeptide and also inhibits gastric emptying. CCK stimulates gastric acid secretion in cats. In humans, dogs, and rats, CCK only stimulates basal gastric acid secretion and inhibits gastric acid secretion caused by gastric acid-stimulating hormone. CCK is a classic satiety factor that stops feeding by producing satiety and inhibiting gastric movement. Recent studies have found that CCK can promote the proliferation of certain cancer cells. CCK stimulates the growth of small cell clones of lung cancer through its receptors and promotes the growth of xenograft pancreatic cancer. The effect of CCK on tumor cell growth provides a new method for the development of new anti-tumor drugs.