title: Comparative release of alkaline phosphatases from Serratia marcescens by osmotic shock and polymyxin B treatment.
abstract: The comparative release of periplasmic enzymes and proteins from two strains of Serratia marcescens by osmotic shock and polymyxin B treatment was studied. There were significant qualitative and quantitative differences in the materials released by these two techniques. The osmotic shock procedure released a higher level of alkaline phosphatase activity and a greater number of protein components than the polymyxin B treatment. The molecular weights of the active components released by the two techniques were shown to be 190,000 +/- 10,000 (A'), 140,000 +/- 10,000 (A) and 110,000 +/- 10,000 (B) daltons. Components released by polymyxin B were also released by osmotic shock. However, the reverse was not true. Component B in the osmotic shock fluids was by far the most active. The differences in the release mechanisms of the two techniques were discussed. It is suggested that polymyxin B treatment is the method of choice because of its selectiveness and mildness, despite the rather low level of activity of alkaline phosphatase released.
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism*; D001426:Bacterial Proteins / Q000032:analysis; D004352:Drug Resistance, Microbial; D008970:Molecular Weight; D009997:Osmotic Pressure; D011113:Polymyxins / Q000494:pharmacology*; D012706:Serratia marcescens / Q000032:analysis / Q000187:drug effects / Q000201:enzymology*
chemical_list: D001426:Bacterial Proteins; D011113:Polymyxins; D000469:Alkaline Phosphatase