Abstract
Hemolysin-like proteins (HLP) exist not only in pathogenic but also in non-pathogenic bacteria. Although these proteins seem to have a physiological function other than hemolysis, it has not been clarified. In a previous study, we purified HLP from Synechocystis sp. PCC6803 and showed that it underwent a large conformational change from 90 kDa to >200 kDa by heat treatment in the presence of SDS. In the present study, we found that when the HLP was heated in the absence of SDS and then supplemented with calcium ion, the mobility returned to 90 kDa. This fact suggests that the release/binding of calcium ion induces the conformational change of the protein. In immuno-electron microscopy, abundance of HLP molecules existed in the surface layer. We expect that the conformational change of the protein is related to the motility of the bacterium. We will discuss this hypothesis in the presentation.
