CATHEPSIN-L-LIKE PROTEASE FROM XENOPUS EMBRYOS THAT IS STIMULATED BY NUCLEOSIDE PHOSPHATES AND NUCLEIC-ACIDS

An acid thiol protease that was activated at an early stage of embryog enesis was purified from Xenopus embryos. The N-terminal amino acid se quence(16 residues) of the heavy chain of the enzyme was similar to th at of cathepsin L. The proteolytic activity of the protease was enhanc ed by ATP. Other nucleoside triphosphates, AMP and nucleic acids also enhanced the proteolytic activity. The possible mechanism and biologic al significance of the activation of the protease in Xenopus embryos a re discussed.