Changes in Lewis Blood Group Specificity Induced by Enzymes

Abstract

1. A crude enzyme preparation from Bac. Fulminans or from Bac. Cereus O(H) contained O(H)- and Le^b-decomposing enzymes, and when applied on an O(H)+, Le(a±b+) substance, destroyed O(H) and Le^b activity together with enhancing Le^a activity. But when applied on an O(H)+, Le(a±b-) substance, it only destroyed O(H) activity without enhancing Le^a activity. When, however, the O(H)+, Le(a±b+) substance was incubated with purified preparation from Bac. Fulminans, which contained only the O(H)-decomposing enzyme, abolishment of O(H) activity alone was observed, but not enhancement of Le^a activity. These results seem to indicate the following with regard the process of formation of blood group substances: From a precursor substance are individually developed O(H) and Le^a substance, and on the basis of O(H) substance are formed A and B substance, and on the basis of Le^a substance is formed Le^b substance. However, when the crude enzyme preparation from Bac. Fulminans or from Bac. Cereus O(H) was applied on OLe(a-b+) red cells, it was difficult to recognize appearance of Le^a activity, though O(H) and Le^b activity were abolished. 2. When the A-decomposing enzyme from Cl. Tertium and the B-decomposing enzyme from Cl. Maebashi were applied on A and B substance or red cells with Le^b activity, respectively, slight increase in Le^b activity was observed together with enhancement of O(H) activity. When AB substance or AB red cells were incubated with both the A- and B-decomposing enzymes, these were transformed into a substance or red cells having O(H) activity nearly to the same degree as that of O(H) substance or O red cells.