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Purification
and characterization of a novel protease from Bacillus
strain SAL1
Sadia Almas1,2*,
Abdul Hameed1,
Dennis Shelly2
and Priya Mohan2
1Department
of Microbiology, Quaid-i-Azam University, Islamabad, 45320,
Pakistan.
2Department of Chemistry and Biochemistry, Texas Tech
University, Lubbock, Texas, 79409, USA.
*Corresponding author. E-mail:
sadiamalik305@gmail.com.
Accepted 27 July, 2009 |
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The purification and characterization of
alkaline protease from a
Bacillus
strain SAL1, isolated from tannery waste have been reported
in this paper. This protease was
purified to homogeneity by the combination of ammonium
sulfate precipitation, DEAE sephacryl
ion exchange and phenyl sepharose hydrophobic
interaction chromatography.
The protease was purified up to 11.18 fold and had a
specific activity of 4250 PU/mg. The enzyme was a monomeric protease with a relative molecular mass
of 27 kDa by SDS-PAGE.
Proteolytic activity of the enzyme was detected by gelatin
zymography, which gave a very clear protease activity
zone
on gel.
Molecular mass of the purified protease was also determined
by
matrix-assisted laser desorption ionization-time-off light-
mass spectrometry
(MALDI-TOF-MS) that corresponded to the mass determined by
SDS-PAGE.
The enzyme exhibited its optimal activity at 60°C and at pH
9.
The enzyme was stable in the pH range of 7.0 – 10.0 and was able to maintain its stability at 50°C for 1 h.
Key words:
Alkaline protease, Bacillus subtilis, purification,
characterization, tannery waste,
DEAE sephacryl, chromatography. |
