Acid and alkaline phosphatases of Capnocytophaga species. III. The relationship of the enzymes to the cell wall.

Abstract

Acid (AcP) and alkaline phosphatase (AlP) were localized by physicobiochemical techniques. Greater than 53% of the phosphatases were detected, following sonication, in a low speed centrifugation pellet while osmotically shocked and spheroplasted Capnocytophaga species released only 9-28% and 11-43% of the cellular phosphatases, respectively. French pressure cell disruption was more effective in releasing the phosphatases. Cell fragments were separated into cell wall, cytoplasmic membrane, and soluble fractions as determined by marker enzyme, chemical composition, transmission electron microscopy, sodium dodecyl sulphate - polyacrylamide gel electrophoresis (SDS-PAGE) protein analysis, and gel diffusion. AcP and AlP was partitioned between the isolated cell wall (31-46%) and soluble material (33-61%), with greater than 60% of the phosphatases remaining with the cell wall following Triton X-100 treatment. The amount of phosphatase at the surface of intact C. ochracea was quantitated by specific 125I-protein labelling.