An electrophoretic and biochemical analysis of acid phosphatase in the tail of Xenopus laevis during development and metamorphosis

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AbstractThe properties of acid phosphatase from tail tissues of Xenopus laevis tadpoles have been investigated by means of acrylamide gel electrophoresis and biochemical assay with alpha‐naphthyl acid phosphate as substrate. Studies were made on intact tails during development and spontaneous metamorphosis, and on isolated tail tips undergoing thyroxine‐induced regression in culture.Quantitative and qualitative changes in acid phosphatase are found to occur during the process of tail resorption. The same types of changes are found during both spontaneous metamorphosis and thyroxine‐induced regression in culture, although the magnitude of these changes is greater during spontaneous metamorphosis. Tail resorption is characterized by increases in total activity (per tail) and specific activity (per unit of protein) of acid phosphatase, as well as changes in the pH optimum and heat sensitivity of the enzyme. Electrophoresis of enzyme preparations from whole tails and different parts of the tail resolves two distinct forms of the enzyme which are both present throughout growth and regression. Densitometric tracings of these gels reveal that the ratio of one form to the other remains constant during growth and the early stages of tail regression. However during late stages of tail regression this ratio becomes significantly altered, due primarily to an increase in one form. Biochemical analysis of enzyme preparations subjected to hypotonic conditions and to Triton X‐100 indicates that there is an increase in the proportion of soluble versus bound enzyme in tail tissues undergoing advanced atrophy. Possible implications of these results are discussed.