Studies on American Paragonimiasis. III. Phosphomonoesterase Activity

Abstract

Acid and alkaline phosphomonoesterase activity has been studied in Paragonimus kellicotti Ward, 1908. The enzymes have been partially purified by differential centrifugation and column chromatography on P-60 polyacrylamide gel. These steps also removed endogenous inorganic phosphate which allowed subsequent reactions to be completed at zero-order kinetics. The partially purified enzymes exhibited maximal activity at pH 4.5 and 9.0 against a variety of substrates. In addition, three other substrates were hydrolyzed at a maximal rate at other pH values. These included glucose6-phosphate at 6.8, AMP at 7.2, and fructose-1, 6-diphosphate at 10.0. These data indicate that a complex group of enzymes are involved in the breakdown of phosphomonoesterases by Paragonimus kellicotti. The enzymes acid phosphatase and alkaline phosphatase are known to attack a variety of both natural and synthetic substrates. They have been extensively investigated over the past decades, and have been found to occur in a number of living organisms (Schmidt, 1961; Stadtman, 1961). The distribution of these enzymes in parasites has been studied by both biochemical and histochemical means (von Brand, 1952; Bullock, 1958; Ma, 1964) and some purification of acid phosphatase has been achieved (Ma, 1964). The objective of the present paper was to determine what phosphomonoesters are attacked by enzymes from Paragonimus kellicotti Ward, 1908, and to what extent. In addition, the enzymes have been partially purified and some of their properties ascertained.