SerpinI2 (pancpin) is an inhibitory serpin targeting pancreatic elastase and chymotrypsin
| Autor: | Gareth T. Grehan, Wayne J. Higgins, Kieran Wynne, D. Margaret Worrall |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
0301 basic medicine
Somatostatin-Secreting Cells Serine Proteinase Inhibitors medicine.medical_treatment Biophysics Serpin Biochemistry Analytical Chemistry Cell Line Substrate Specificity 03 medical and health sciences medicine Acinar cell Escherichia coli Chymotrypsin Trypsin Amino Acid Sequence Molecular Biology Pancreatic elastase Serpins Serine protease Protease 030102 biochemistry & molecular biology biology Pancreatic Elastase Sequence Homology Amino Acid Elastase Molecular biology Recombinant Proteins Neoplasm Proteins 030104 developmental biology biology.protein medicine.drug |
| Zdroj: | Biochimica et biophysica acta. Proteins and proteomics. 1865(2) |
| ISSN: | 1570-9639 |
| Popis: | SerpinI2/Pancpin/MEPI is a 46kDa member of the serpin (serine protease inhibitor) superfamily. It is downregulated in pancreatic and breast cancer, and associated with acinar cell apoptosis and pancreatic insufficiency when absent in mice. However, the target protease and protein properties of serpinI2 are previously uncharacterised. We have expressed and purified recombinant serpin I2 in E. coli. The protein exhibited thermal instability typical of inhibitory serpins, which was lost following RCL cleavage. SerpinI2 did not inhibit trypsin, but was found to inhibit pancreatic chymotrypsin and elastase with Kass values >105M-1s-1, and with stoichiometry of inhibition of 1.4 and 1.7 respectively. Mutagenesis of the predicted critical hinge region residue Ser344 abolished inhibitory activity, and a cleavage site C-terminal to Met358 was identified. The protein is also prone to polymerisation/aggregation at 45°C, a characteristic of serpins associated with disease. This study therefore reveals a function for serpinI2 and supports the hypothesis that this protein can protect pancreatic cells from prematurely activated zymogens. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|
Full Text from ScienceDirect