A new repetitive protein from Xenopus laevis skin highly homologous to pancreatic spasmolytic polypeptide |
| |
Authors: | W Hoffmann |
| |
Affiliation: | Max-Planck-Institut für Psychiatrie, Abteilung Neurochemie, Martinsried Federal Republic of Germany. |
| |
Abstract: | A cDNA sequence has been used to derive the precursor structure of a highly repetitive protein in Xenopus laevis skin. From the sequence of a whole family of secretory proteins can be predicted containing a classical hydrophobic signal sequence at the NH2-terminal end of the precursor. The proteins contain four domains with high homology to porcine pancreatic spasmolytic polypeptide. These four cysteine-rich, presumably physiologically active domains are separated in the molecule by a repetitive element, locating two such domains to the NH2 terminus of the precursor protein and the remaining two to the COOH-terminal end. The separating spacer consists of very unusual, precise, threonine and proline-rich repeats containing 9 residues which could be targets for extensive O-glycosylation. Additionally, processing at two pairs of basic residues is suggested to liberate two polypeptides ("spasmolysins") and "spasmolysin-glycoprotein." |
| |
Keywords: | |
|
|