Correlation of Isozyme Patterns of S-Adenosylmethionine Synthetase with Fetal Stages and Pathological States of the Liver

摘要: Abstract The liver is the most active organ engaged in S-adenosylmethionine metabolism. S-Adenosylmethionine synthetase isozymes (EC 2.5.1.6) were studied normal, fetal, and pathological livers including hepatoma to correlate their activities with developmental stages pathophysiological states of liver. Three synthetase, namely low, intermediate, high-Km, have been identified from adult rat human livers. Km (methionine) are 3.6 μm, 23 1.03 mm for 3.1 20 0.65 isozymes. high-Km isozyme could be distinguished other by its dependency on sulfhydryl reagents, activation dimethyl sulfoxide, chromatographic behaviors Sepharose 6B DEAE-cellulose columns. activity low-Km isozyme, a lesser extent that intermediate-Km was greatly enhanced characteristic rapid growth, such as newborn, regenerating In contrast, undetectable fetal reduced during growth phase remnant following partial hepatectomy. Only detectable Novikoff hepatoma, indicating unique metabolic feature associated this tumor respect synthetase. Such an aberration may significant bearing neoplasia. Livers patients who died hereditary tyrosinemia showed abnormal patterns either undetectable, thus resembling pattern, or present relatively low amount. It suggested development partly responsible methionine metabolism hepatic dysfunctions often these patients.