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Updated: Jun 25, 2026
Total Protein Extraction and 2-D Gel Electrophoresis Methods for Burkholderia Species
Published on: October 15, 2013
Identification of a serine protease from a Bacillus sp. using multiple loading of O'Farrell-type isoelectric focusing
Nack-Shick Choi1, Jong Hyun Choi, Jung-Hoon Yoon
1Enzyme Based Fusion Technology Research Team, Molecular Bioprocess Research Center, Korea Research Institute of Bioscience and Biotechnology, Jeonbuk, 580-185, Korea.
Abstract:
A protease was purified from Bacillus sp. DJ isolated from Doenjang, a traditional Korean fermented food. Its molecular weight (MW) and isoelectric point (pI) were 18-19 kDa and 6.0-6.5 using 1- or 2-D fibrin zymography, respectively. The protease was optimally active at pH 9 and 55 degrees C. Activity was inhibited by 1 mM PMSF, but not by EDTA, EGTA, aprotinin, or leupeptin, indicating that the protease is a serine protease. By using a new electrophoretic technique, multiple loading of O'Farrell-type isoelectric focusing (IEF) slab gel, the first amino acid residues of the N-terminal sequence of the protease were determined as HPLVLVDPIL, which is 80% identical with serine proteases of the subtilase family.
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