Separation of Proteinase from Embryos during Incubation of chicken Eggs and Control of the Activity by Endogenous Proteinase Inhibitor

Very small amounts of two kinds of proteinases (A and B) were separated from the extract of embryosfifty chicken eggs at the 7th day of incubation by the respective affinity chromatography onovoinhibitor-Sepharose and ovomucoid-Sepharose columns. The activities of these enzymes wererespectively very weak and could be barely assayed using kunitz's casein digestion method by takingthe reacting time of 4或5 hr. Optimum pH value of enzyme A for the reation was ranging from 8 to10 and thet of enzyme B was approximately 6.0. Optimum temeratures of these enzymes wererespectively 42 C. Enzyme A activity不受Mg， Cu ions and EDTA，but inhibited by that of Fe^<2+> or Zn ion (10^<-3>M) by ca. 45 %. The enzyme was inactivated bymodification with diisopropylflurophosphate and inhibited by endogenous ovoinhibitor,不含ovomucoid. The enzyme, moreover, did not hydrolyzed p-tosyl arg.-methylester，but hydrolyzed benzoyltyr. ethylester. From these results，enzyme A was presumed to be chymotrypsin-like enzyme. differing from enzyma A，B not inhibited by ovoinhibiter, but inhibited by ovomucoid；it not hydrolyze BTEE, but hydrolyzed TAME. Therefore，enzyme B was presumed to be trypsin-like enzyme.这些enzymes differed in the chemicalconstitutions. Both the enzymes hydrolyed very slowly diluted egg white solutions (concn.：4%) after inactivation of endogenous inhibitors (ovo-inhibitor and ovomucoid) by heating. These实验结果suggest the control or regulation of proteolysis by endogenous proteinaseinhibitors during chicken embryonic growth。

Very small amounts of two kinds of proteinases (A and B) were separated from the extract of embryos of fifty chicken eggs at the 7th day of incubation by the respective affinity chromatography on ovoinhibitor-Sepharose and ovomucoid-Sepharose columns. The activities of these enzymes were respectively very weak and could be barely assayed using kunitz's casein digestion method by taking the reacting time of 4 or 5 hr. Optimum pH value of enzyme A for the reation was ranging from 8 to 10 and thet of enzyme B was approximately 6.0. Optimum temeratures of these enzymes were respectively 42゜C. Enzyme A activity was not affected by addition of Mg, Cu ions and EDTA, but inhibited by that of Fe^<2+> or Zn ion (10^<-3>M) by ca. 45 %. The enzyme was inactivated by modification with diisopropylflurophosphate and inhibited by endogenous ovoinhibitor, and not inhibited by ovomucoid. The enzyme, moreover, did not hydrolyzed p-tosyl arg.-methylester, but hydrolyzed benzoyltyr.-ethylester. From these results, enzyme A was presumed to be chymotrypsin-like enzyme.Differing from enzyma A, B was not inhibited by ovoinhibiter, but inhibited by ovomucoid; it did not hydrolyze BTEE, but hydrolyzed TAME. Therefore, enzyme B was presumed to be trypsin-like enzyme. These enzymes differed in the chemical constitutions. Both the enzymes hydrolyed very slowly diluted egg white solutions (concn.: 4 %) after inactivation of endogenous inhibitors (ovo-inhibitor and ovomucoid) by heating. These experimental results suggest the control or regulation of proteolysis by endogenous proteinase inhibitors during chicken embryonic growth.