A new group of mitogenic lectins from invertebrate sources.

In the haemolymph of the Tridacnid bivalve clams anti-galactans occur which do not have only glycosubstance precipitating and cell agglutinating properties, but also show mitogenic activity with respect to the blast transformation of human peripheral lymphocytes. This new property can be inhibited in a specific way by galactans and is destroyed by the degradation of the mitogenic lectin into subunits by polymer bound pronase. Quite a number of invertebrate haemolymph samples and snail albumin gland extracts, containing agglutinin activity, proved to have no mitogenic potency. The only exception was found in an extract of the snail albumin gland of Ampullaria canaliculata which contained a strong mitogen of the lectin type.