| Abstract: | Electrofocusing patterns of plasma fucosyltransferases provide information concerning marrow status of patients with myeloproliferative disorders. Three enzymes were detected in normal plasmas using an acceptor terminating in the sequence N-acetylglucosamine-galactose. The enzyme which focused at pH 4.7 was elevated during rapid proliferation of myeloid cells, e.g., acute myelogenous leukemias and certain infectious diseases. Activity at pI = 5.1 was decreased in acute myelogenous leukemia patients, and from other observations, appears related to the level of erythropoietic activity. Acceptor studies show this enzyme to be specified by the H gene. A third enzyme focused at pH 5.5 and appeared to be correlated with a later step in granulocytes maturation. Two other plasma fucosyltransferases (pl = 5.6 and 8.3) were detected with a high-molecular-weight acceptor terminating in N-acetylglucosamine. This activity was markedly elevated during regeneration of a normal marrow population during drug-induced remission of acute myelogenous leukemia. Additional isoenzymes were detected, using this acceptor, in plasma of patients with certain solid tumors and multiple myeloma. However, the new isoelectric points observed (pH 6.0, 6.9, and 7.8) suggest these enzymes are probably not derived from hematopoietic tissues. |
