Purification and characterization of an alpha-mannosidase of sea-squirt.
An alpha-mannosidase was isolated from the extract of acetone powder of CHCl3-treated internal organs of the sea-squirt, Styela plicata. The enzyme was purified 4,110-fold in 11% yield. The preparation was fairly homogeneous on disc and SDS-polyacrylamide gel electrophoreses and Sephadex G-200 chromatography. The enzyme had an estimated molecular weight of 275,000 by gel chromatography and 70,000 by SDS-polyacrylamide gel electrophoresis, and was therefore considered to be a tetramer. The optimum pH for the enzyme activity was 3.4 but the stable pH range was from 4 to 6. The isoelectric point was 5.0. The enzyme was activated by Zn2+ but inhibited by Cu2+, Fe2+, Hg2+, and EDTA. The isolated enzyme released mannose not only from stem bromelin glycopeptide and ovalbumin glycopeptide but also from yeast mannan.
D000818:Animals; D002413:Cations, Divalent / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D046911:Macromolecular Substances; D008361:Mannosidases / Q000037:antagonists & inhibitors / Q000302:isolation & purification* / Q000378:metabolism; D008970:Molecular Weight; D013379:Substrate Specificity; D014561:Urochordata / Q000201:enzymology*; D043323:alpha-Mannosidase
D002413:Cations, Divalent; D046911:Macromolecular Substances; D008361:Mannosidases; D043323:alpha-Mannosidase