[Interaction of aldolase with pigeon erythrocyte plasma membranes]

Osmotically hemolysed pigeon erythrocytes retain a considerable part of the total cell content of aldolase activity. After washing off the ghosts from hemoglobin and removing the nuclei, a considerable portion of aldolase activity is found in the supernatant. The retained part of aldolase is rather firmly bound to plasma membranes (PM), as evidenced by the fact, that double washing with a mixture of 0.3 M sucrose, 0.01 M tris-HCl (pH 7.4) and 0.004 M MgCL2, or with 0.15 M NaCl or H2O does not appreciably decrease the aldolase activity of PM. Only washing of PM with 0.5 M NaCl results in appreciable decrease of aldolase retention by PM. The binding of aldolase proved to be temperature sensitive: after heating the binding of aldolase to PM specifically decreased. These data suggest that the interaction of the enzyme with PM of pigeon erythrocytes occurs in the intact cell and may be of physiological significance.