Serum Alkaline Phosphatase of Large Molecular Weight

Bio-Gel A-5m and Bio-Gel A-150m gel-chromatography of serum alkaline phosphatase was carried out. Large molecular alkaline phosphatase in serum which exhibited alkaline phosphatase activity prior to any treatment was obtained and assumed tobe cell debris enzyme. By the treatment with Triton X-100, its molecular weight became smaller and alkaline phosphatase activity increased. Treatment with DOC also lowered the molecular size, but alkaline phosphatase activity was inhibited. Electron microscopic study of ultracentrifugation sediment of this material revealed cell debris like features possessing alkaline phosphatase activitythe molecular weight of this meterial may be over ten million with a very broad size distribution.