ABC  Vol.2 No.4 , November 2012
Elimination of a disulfide bridge in Aspergillus niger NRRL 3135 Phytase (PhyA) enhances heat tolerance and optimizes its temperature versus activity profile
In this study, the optimum temperature was lowered while the residual phytase activity after heating to 70℃ was raised in a widely utilized phytase, Aspergillus niger NRRL 3135 PhyA. This was accomplished by site-directed mutagenesis of the cysteines that are involved in the formation of a single disulfide bridge (DB). When compared to wild type (WT), three of the four mutant phytases displayed a lower optimum temperature, 42℃, and up to a four-fold increase in activity after heating. These findings have a potentially broad application to be incorporated along with other desirable features to engineer a phytase with superior physical and chem-ical attributes for animal feed applications.

Cite this paper
Mullaney, E. , Sethumadhavan, K. , Boone, S. , Lei, X. and Ullah, A. (2012) Elimination of a disulfide bridge in Aspergillus niger NRRL 3135 Phytase (PhyA) enhances heat tolerance and optimizes its temperature versus activity profile. Advances in Biological Chemistry, 2, 372-378. doi: 10.4236/abc.2012.24046.
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