Cell-wall proteins of Staphylococcus aureus : a kinetic study of release by lysostaphin.

The kinetics of cell-wall hydrolysis of Staphylococcus aureus (strain Cowan I) by lysostaphin was studied by turbidity, quantitative determination of hexosamines, phosphorus, total proteins, protein A and by electron microscopy. In our experimental conditions, the lytic activity of lysostaphin was very fast and no characteristic cell-wall structures could be seen after five minutes. The release of hexosamines, phosphorus and protein A was synchronous and could be recorded even though turbidity had become stable. At the end of the hydrolysis, the totality of these components was solubilized. Total proteins represented about 14% of the cell-wall dry weight. During hydrolysis protein A was the only protein solubilized.