In Vitro Release of Lectins From Phallusia mamillata Hemocytes After Their Fractionation on a Density Gradient

Hemocytes were fractionated by centrifugation on a discontinuous Percoll density gradient from the hemolymph of Phallusia mamillata. Results obtained from microcultures of the fractionated hemocytes, sugar-inhibition experiments, SDS-PAGE, and immunoblotting indicate that "compartment cells" release cellular-type (CL) lectins that are specific for a-lactose and lactulose. The released lectins have the same properties as the CL lectins that were previously isolated from sonicated unfractionated hemocytes, but they differ in terms of some molecular and immunological properties from the lectins (SL) purified from the serum. SLs were never found in the supernatants from microcultures ofthe fractionated hemocytes.