The Staphylococcal Phospho enol pyruvate‐Dependent Phosphotransferase System Purification and Characterisation of the Galactoside‐Specific Membrane‐Component Enzyme II

• Published in: European journal of biochemistry Vol. 113; no. 2; pp. 289 - 294
• Main Authors: SCHÄFER, Angela, SCHRECKER, Otto, HENGSTENBERG, Wolfgang
• Format: Journal Article
• Language: English
• Published: 01.01.1981
• ISSN: 0014-2956; 1432-1033
• DOI: 10.1111/j.1432-1033.1981.tb05065.x

The galactoside‐specific membrane‐bound component of the staphylococcal phospho enol pyruvate‐dependent phosphotransferase system, enzyme II lac , was purified to homogeneity. The purification procedure involved several extractions steps at the particulate state, followed by solubilisation with Triton X‐100. Up to this stage the biological activity of enzyme II was preserved. Isolation of the homogeneous protein involved gel filtration of the dodecylsulfate‐denatured material. An apparent molecular weight of the polypeptide chain was estimated by dodecylsulfate gel electrophoresis. The 55000‐ M r protein is visible in dodecylsulfate gels upon induction of the staphylococcal lac operon as a more intensively stained area. Antibodies against the denatured 55000‐ M r protein inhibit the mutant complementation assay of enzyme II offered as membrane fragments. This demonstrates that the 55000‐ M r protein and enzyme II lac are identical. Polarity and the solubility of the protein in detergents are typical for an integral membrane protein.