| Abstract: | Amphibian embryo chymotrypsin and papain inhibitor (ACPI) purified by the procedure described in this paper produces a single band on sodium dodecyl sulfate (SDS) gel electrophoresis and a single peak on Sephadex G-75 chromatography. Except for its enzyme specificity, ACPI is very similar to amphibian embryo trypsin inhibitor (ATI). Its molecular weight is about 10,500 and its amino acid composition is typical of many naturally occurring protease inhibitors. Inhibition develops slowly, is retarded by the presence of substrate and is temporary. ACPI is localized in the yolk platelets and its disappearance both from whole embryos and from select tissue types corresponds closely with that of ATI. Possible roles for amphibian embryo proteases and protease inhibitors in development are discussed. |
