抄録
Studies were made to clarify the mechanism by which APase in serum came out of different organs. The enzymes were prepared f rom rat intestines and kidneys by two ways, one by column chromatography on DEAE cellulose, the other on Sepharose 4B. The enzymes obtained by the first way was designated as a soluble fraction, that by the latter as a particulate fraction.
1) When the soluble fraction was treated with acid (pH 2.0), almost all enzymic activity of the kidney was lost immediately and that of the intestines decreased by about 10% of the original whithin the first 10 minutes. When the acid treatment was carried out after mixing both intestines and kidneys, the decrease in the activity caused by the treatment was much less than the total of losses caused by the separate acid treatment of the intestines and kidneys. The decrease in enzymic activity by the acid treatment was not depend on the amount of the material used under these experimental conditions. No appreciable change in effect of the acid treatment of the intestinal APase was observed by prior addition of bovine serum albumine into the enzyme solution.
2) Na-laulylsulfate treatment of the particulate fraction made its molecular size smaller on Sepharose 4B column chromatography. The elution pattern of enzymic activity of the laurylsulfate treated sample prepared by mixing both intestines and kidneys was somewhat different f rom the pattern presumed from those obtained by separate treatment by laurylsulfate of the intestines and kidneys.
3) In the experiments in vivo, the partially purified intestinal APase injected was actually subjected to some changes in its property regarding to its sensitivity to L-phenylalanine.
From the above experimental evidence obtained by the in vitro and in vivo experiments, it is conceivable that a) APase attaches to some materials in a difinites ize or the enzyme associates or dissociates with some structual units in size b) there are some mutual interactions amoung APase from different organs.
