Gastrin family

The gastrin family, which consists of gastrin, CCK, cerulein, enkephalin, and motilin, and... 

Fig. 1. The C-terminal structure of members of the gastrin family. The members are characterized by the same active site, i.e., the C-terminal tetrapeptide amide (shown in the internal box). Another characteristic is an O-sulfated tyrosyl residue close to the active site. In gastrin peptides the sulfated tyrosyl residue is located in position six (as counted from the C-terminus) in cholecystokinins it is position seven. The frog skin peptide caerulein therefore acts as cholecystokinin in mammals. Cionin is a neuropeptide from the protochordate, Ciona intestinalis. Cionin is unique in having O-sulfated tyrosyl residues in both positions six and seven. The cionin structure is therefore likely to correspond to that of the common ancestor of gastrin and cholecystokinin.

Potential Bioactive Conformations of Hormones of the Gastrin Family... 

Gastrin family, a member of the gastroen-teropancreatic peptide families. This family comprises the mammalian hormones gastrin and cholecystokinin, the pro-tochordean neuropeptide cionin, and... 

Growth-Arrest-Specific protein 2 Domain Gastrin/cholecystokinin/caerulein family Dynamin GTPase effector domain Gelsolin homology domain G protein y subunit-like motifs Glycoprotein hormone a chain homologs... 

After the early discovery of a tyrosine 0-sulfate residue in bovine fibrinopeptide B, 15 this posttranslational modification which occurs ubiquitously in proteins was also detected in a series of biologically active peptides such as the neurohormones of the gastrin/cholecysto-kinin (CCK) family of peptides, phyllokinin, Leu-enkephalin, and the thrombin inhibitor hirudin listed in Table 1. 

The gastrin receptor is one of the receptors that bind cholecystokinin (Table 13.4), and is known as the CCK-B receptor it is another member of the G-protein-coupled receptor family. 

Figure 1. Sequence homologies among members of the insect sulfakinin family and human gastrin II and cholecystokinin-12 (CCK-12). Dashed lines denote residues in which the nucleotide codons could differ by a single nucleotide. Abbreviations LSK = leucosulfakinin, PSK = perisulfakinin, DSK = drosulfakinin, LMSK = Locusta m/gruron -sulfakinin.

Phe) (9), the insect SK s (His), and the vertebrate gastrin/CCK peptide family (Trp) (9), suggesting conservation of aromatic character at this position throughout the molecular evolution of these homologous myotropic peptides. 

Jn Figure 2.1U, examine the order of ainiriD adds at the C termiivi of gastrin and cholecystokin. How many amino acids are identical in the two hormones Are any other identical sequences shared by these hormones Ihcsc questions are relevant lo the concept that a number of hormones with different functions are actually part of the same family of hormones. A number of proteins, such as various enzymes, hormone receptor proteins, and DNA-binding protcirLS, also share similar primary sequences and thus may becortsidered members of specific families of proteins. 

ATPase. Annu. Rev. Pharmacol. Toxicol.. 35.277-305. gastrin is the name of members of a family of peptide hormones secreted in the neuroendocrine ceils of the mucosa of the stomach, and secreted into the portal blood. 

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