ENZYMATIC-PROPERTIES OF ALPHA-AMYLASE FROM SEA-URCHIN, STRONGYLOCENTROTUS-NUDAS

alpha-Amylase from the digestive tube of sea urchin, Strongylocentrotu s nudas, was isolated by acetone powder, ammonium sulfate fractionatio n and ion exchange chromatography. Optimum pH of the alpha-amylase was similar to 7.3 in 50 mM NaCl and similar to 6.0 in the absence of NaC l at 30 degrees C. Chloride ions activate amylolytic activity in addit ion to causing a shift of the optimum pH; the K-d value was 2.4 mM at 30 degrees C. The action pattern of alpha-amylase using amylose as a s ubstrate showed a multiple attack mechanism similar to porcine pancrea tic alpha-amylase. Enzymatic properties oi alpha-amylase from the sea urchin were nearly the same as those of mammalian alpha-amylases, alth ough the digestive organs are still not fully evolved.