Na,K-ATPase in crystalline form investigated by scanning force microscopy.

Na,K-ATPase has been isolated in purified membrane fragments from kidney tissue and crystallized by phospholipase treatment to obtain two-dimensional, membrane-bound protein crystals. Scanning force microscopy has been used to identify and analyze the topography of the membrane fragments. Specific patterns in accordance with electron microscopic images have been found. In biological material under physiological conditions the scanning force is a crucial parameter for the resulting image at high resolution.