Glycogen synthase from human and bovine polymorphonuclear leukocyte Immunochemical characterization and comparison to glycogen synthase from rat and rabbit muscle and liver cells

Glycogen synthase from human and bovine polymorphonuclear leukocytes was purified to homogeneity. Rabbit antisera were raised against the two glycogen synthases and used for immunochemical analysis. Western blotting analysis showed that the subunit of glycogen synthase in crude homogenates of human and bovine leukocytes in both cases has an M_r of 85 000. The existence of a cross-reactivity between the two enzymes and the corresponding antisera demonstrates immunological similarities between bovine and human leukocyte glycogen synthase. In addition, both antisera recognize glycogen synthase in crude cellular extracts from rabbit and rat liver and from skeletal muscle. Leukocyte glycogen synthase, therefore, cannot be classified as either muscle (M-type) or liver (L-type) glycogen synthase and our results do not support the proposed immunochemical distinction between M- and L-type glycogen synthase.