Amylase polymorphism in crustacea decapoda: electrophoretic and immunological studies

Abstract

Alpha-amylase polymorphism was studied in 40 species of crustaceans belonging to four infraorders of Decapoda. Specific activities of alpha-amylases from hepatopancreas extracts of the same species were also measured. Very low specific activities were measured for Carcinus, Munida, Nephrops and Palinurus, whilst high activities were measured for shrimps and crabs. Amylases from one species of each of the four infraorders of Decapoda were purified by affinity chromatography. Very few differences in the specific activities of the pure enzymes were detected. The amylase content of crude extracts ranges between 0.1% of total protein, from the hepatopancreas in Carcinus maenas and Eupagurus bernhardus, to 1% Penaeus vannamei and Procambarus clarkii. The apparent molecular weight, determined by denaturating electrophoresis, was 55 kDa for Eupagurus and Procambarus amylases but only about 30 kDa for Carcinus and Penaeus amylases. Using immunodiffusion, rocket immunoelectrophoresis and enzyme inhibition with antibodies against Palaemon serratus α-amylase, we have shown that all the Decapod α-amylases are immunologically related but that they are different from those of Copepods, Bacillus or pig pancreatic amylases. The use of these data for phylogenetic analysis is discussed.