title: alpha-N-Acetylgalactosaminidase from squid liver: purification and characterization of two enzymes.
abstract: Squid liver contains two kinds of alpha-N-acetylgalactosaminidases, which could be separated by gel filtration on Sephadex G-200 or by SP-Sephadex ion exchange chromatography. The two alpha-N-acetylgalactosaminidases, alpha-N-acetylgalactosaminidase I and II, were purified by procedures involving extraction, ammonium sulfate precipitation, and chromatographies on SP-Sephadex, Sephadex G-100, Sephadex G-200, DEAE-Sephadex, and Sepharose 6B. Enzyme I was purified 1,100-fold and enzyme II 3,000-fold. Both enzymes appeared to be homogeneous based upon the results of disc gel electrophoresis. Enzyme I had a pH optimum of 3.0 and was heat-stable. It was inhibited by N-acetylgalactosamine and galactose. On the other hand, enzyme II had a pH optimum of 4.2 and was heat-labile. Galactose did not affect the enzyme activity. In contrast to enzyme I, which showed alpha-galactosidase activity even in the final preparation, enzyme II was practically free from alpha-galactosidase activity.
mesh_terms: D000818:Animals; D002850:Chromatography, Gel / Q000379:methods; D002852:Chromatography, Ion Exchange / Q000379:methods; D049832:Decapodiformes; D006026:Glycoside Hydrolases / Q000378:metabolism; D006596:Hexosaminidases / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007527:Isoenzymes / Q000302:isolation & purification* / Q000378:metabolism; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D048809:alpha-N-Acetylgalactosaminidase
chemical_list: D007527:Isoenzymes; D006026:Glycoside Hydrolases; D006596:Hexosaminidases; D048809:alpha-N-Acetylgalactosaminidase