Porcine pancreatic polypeptide

Extracted porcine C-peptide (21), porcine glucagon (24), porcine monocomponent insulin (25), porcine pancreatic polypeptide (36), porcine proinsulin (30), somatostatin (24), vasoactive intestinal polypeptide (19)... 

The vertebrate NPY family contains such prominent members as pancreatic polypeptide (PP), characterized initially from chicken where PP is synthesized and released from the endocrine cells of the pancreatic islets [204], neuropeptide Y (NPY) found in porcine brain [205] and peptide YY (PYY) isolated from porcine intestine [206]. Such peptides are characterized by a chain length of 36 amino acids and Tyr-amide at the C-terminus. Whereas NPY is exclusively expressed in neurons of mammals and is known to control processes such as stimulation of food intake, vasoconstriction, sexual behaviour and circadian rhythm, PP and PPY are synthesized in endocrine cells of the gut and are inhibitors of gut motility and of the secretion of exocrine products from the pancreas. 

Amland PF, Jorde R, Aandernp S, Burhol PG, Giercksky K-E. Effects of intravenonsly infused porcine GIP on sernm insnlin, plasma C-peptide, and pancreatic polypeptide in non-insnlin-dependent diabetes in the fasting state. Scand J Gastroenterol 1985 20 315-320. 

Avian (aPP), porcine (pPP), bovine (bPP), ovine (oPP), and human (hPP) pancreatic polypeptides have been sequenced (Kimmel et a/., 1975 Floyd et a/., 1977), and the avian hormone has been crystallized (Wood et a/., 1977). X-ray analysis of monoclinic crystals of aPP (Pitts et aL, 1979) initially provided a molecular structure to 3.0 A resolution this has now been extended to 1.4 A resolution (Blundell et a/., 1980 Tickle, 1980). The asymmetric unit comprises one molecule related about a crystallographic twofold axis to an equivalent molecule with which it forms a dimer. The dimers are linked in the crystals through coordination to zinc ions. 

The effect of various peptides and growth factors in small cell lung cancer cells has been reported by Bepler et al [121]. Four peptides isolated from completely different sources with structural similarities represent members of a new family of growth factors [121]. These peptides include 1) a 60 amino acid residue breast cancer- associated pS2 peptide isolated from human gastric juice and the culture media of the human breast cancer cell line MCF-7, 2) a 106 amino acid residue pancreatic spasmolytic polypeptide (PSP) isolated from porcine pancreas and 3) a 49 and 50 amino acid residue peptide predicted from a cyclic DNA isolated from the skin of frog, Xenopus laevis. 

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