Substrate specificity and some physicochemical properties of autolytic enzymes of the bacterium Lysobacter sp. XL 1

• Published in: Biochemistry (Moscow) 2007-07, Vol.72 (7), p.760-765
• Main Authors: Tsfasman, I M, Sitkin, B V, Lysanskaya, V Ya, Stepnaya, O A, Kulaev, I S
• Format: Article
• Language: English
• Subjects: Amidohydrolases - metabolism; Bacterial Proteins - metabolism; Cell Wall - enzymology; Cytosol - enzymology; Endopeptidases - metabolism; Enzymes; Hexosaminidases - metabolism; Hydrogen-Ion Concentration; Lysobacter - enzymology; Muramidase - metabolism; Peptidoglycans; Physicochemical properties; Properties; Substrate Specificity; Temperature
• ISSN: 0006-2979; 1608-3040; 0320-9725
• DOI: 10.1134/S0006297907070103

The substrate specificity of autolytic enzymes of the bacterium Lysobacter sp. XL 1 has been established. The periplasmic enzyme A8, the cytosolic enzyme A1, and the enzyme A10 solubilized from the cell walls and membranes with Triton X-100 exhibit glucosaminidase activity; the cytosolic enzyme A4 and the enzyme A9 solubilized from the cell walls and membranes with LiCl exhibit the muramidase activity. The cytosolic enzymes A3 and A6 have N-acetylmuramoyl-L-alanine amidase activity, and the enzyme A5 exhibits the diaminopimelinoyl-alanine endopeptidase activity. Some physicochemical properties of the most active autolytic cytosolic enzymes of Lysobacter sp. XL 1 (endopeptidases A5 and A7 and N-acetylmuramoyl-L-alanine amidase A6) were studied. The enzymes exhibit maximal activity over a wide range of buffer concentrations in weakly alkaline medium and moderate temperatures. The investigated enzymes are comparatively thermolabile proteins.