Purification and Characterization of Cell Wall-associated N-Acetylmuramyl-L-alanine Amidase from Alkaliphilic Bacillus lentus C-125.
Cells of the facultative alkaliphile Bacillus sp. C-125 grown at neutral pH autolyze rapidly in alkaline buffers of pH 9-10. Alkaline autolytic activity has been found mainly in the cell wall fraction. A peptidoglycanlytic enzyme was extracted from the cell wall fraction suspended in 4M LiCl. The enzyme was identified as N-acetylmuramyl-L-alanine amidase, with a molecular mass of 58kDa. At low salinity, the enzyme formed an aggregate of high molecular mass. The peptidoglycan lytic reaction of this enzyme happened at pH 9.0-10.5 at 37°C. Optimum pH for the reaction was 9.7-10.0. The enzyme was most active at 60°C when assayed at pH 9.0.
a Department of Bioengineering, Faculty of Bioscience and Biotechnology , Tokyo Institute of Technology, Nagatsuta 4259 , Yokohama 226 , Japan.
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Rikizo
a Department of Bioengineering, Faculty of Bioscience and Biotechnology , Tokyo Institute of Technology, Nagatsuta 4259 , Yokohama 226 , Japan.
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Takafumi
a Department of Bioengineering, Faculty of Bioscience and Biotechnology , Tokyo Institute of Technology, Nagatsuta 4259 , Yokohama 226 , Japan.
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Koki
N-acetylmuramyl-L-alanine amidase; alkaliphile; alkaliphilic Bacillus lentus; peptidoglycan lytic enzyme