Isolation, purification and characterization of a pH tolerant and temperature stable proteinaceous protease inhibitor from marine Pseudomonas mendocina
An extracellular protease inhibitor (BTPI-301) of trypsin was purified and characterized from an isolate of Pseudomonas mendocina.
BTPI-301was purified to homogeneity by (NH4)2SO4, precipitation, DEAE Sepharose and CNBr-activated Sepharose chromatography. Homogeneity was proved by native PAGE and SDS-PAGE. The intact molecular mass was 11567 Da by MALDI-TOF analysis. BTPI-301was a competitive inhibitor with a Ki of 3.5 × 10−10 M. It was stable and active at pH 4–12 and also at 4–90 °C for 1 h. Peptide mass fingerprinting by MALDI revealed that the BTPI-301 is a new inhibitor not reported so far with protease inhibitory activity. The pI of the inhibitor was 3.8. The stoichiometry of trypsin-BTPI-301 interaction is 1:1. The inhibitor was specific towards trypsin.
A pH tolerant and thermostable protease inhibitor BTPI-301 active against trypsin was purified and characterized from P. mendocina that could be developed and used as biopreservative as well as biocontrol agent.
KeywordsInhibitory activity Protease inhibitor Pseudomonas mendocina Trypsin
The authors gratefully acknowledge the financial support from Department of Biotechnology, Government of India (Sanction Order No.: BT/PR7906/AAQ/03/281/2006 dated 07.03.2007).
- Chandrasekaran M (1985) Studies on Microbial spoilage of Penaeus indicus. Ph.D thesis Cochin University of Science and Technology School of Marine Sciences, Cochin, pp. 1–258Google Scholar