| Autor: |
Nai-Wan Hsiao, Yeh Chen, Yi-Chia Kuan, Yen-Chung Lee, Shuo-Kang Lee, Hsin-Hua Chan, Chao-Hung Kao |
| Jazyk: |
angličtina |
| Rok vydání: |
2014 |
| Předmět: |
|
| Zdroj: |
Electronic Journal of Biotechnology, Vol 17, Iss 2, Pp 89-94 (2014) |
| Druh dokumentu: |
article |
| ISSN: |
0717-3458 |
| DOI: |
10.1016/j.ejbt.2014.02.002 |
| Popis: |
Background: Aspartic proteases are a subfamily of endopeptidases that are useful in a variety of applications, especially in the food processing industry. Here we describe a novel aspartic protease that was purified from Peptidase R, a commercial protease preparation derived from Rhizopus oryzae. Results: An aspartic protease sourced from Peptidase R was purified to homogeneity by anion exchange chromatography followed by polishing with a hydrophobic interaction chromatography column, resulting in a 3.4-fold increase in specific activity (57.5 × 103 U/mg) and 58.8% recovery. The estimated molecular weight of the purified enzyme was 39 kDa. The N-terminal sequence of the purified protein exhibited 63–75% identity to rhizopuspepsins from various Rhizopus species. The enzyme exhibited maximal activity at 75°C in glycine–HCl buffer, pH 3.4 with casein as the substrate. The protease was stable at 35°C for 60 min and had an observed half-life of approximately 30 min at 45°C. Enzyme activity was not significantly inhibited by chelation with ethylenediamine tetraacetic acid (EDTA), and the addition of metal ions to EDTA-treated protease did not significantly change enzyme activity, indicating that proteolysis is not metal ion-dependent. The purified enzyme was completely inactivated by the aspartic protease inhibitor Pepstatin A. Conclusion: Based on the observed enzyme activity, inhibition profile with Pepstatin A, and sequence similarity to other rhizopuspepsins, we have classified this enzyme as an aspartic protease. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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