PURIFICATION, PROPERTIES, AND N-TERMINAL AMINO-ACID-SEQUENCES OF GUARGUM-DEGRADING ENZYME FROM BACILLUS-CIRCULANS K-1

A guar gum-degrading enzyme of the newly isolated Bacillus circulans K -1 was purified to an electrophoretically homogeneous state, The molec ular weight of the purified enzyme was 62,000 by SDS-PAGE, The purifie d enzyme was separated into at least six isozymes by isoelectric focus ing and the pI of these isozymes were 5.4, 5.5, 5.6, 5.8, 6.0, and 6.2 , respectively, The N-terminal amino acid sequences of the typical thr ee of these proteins were all the same, s-Leu-Leu-Asp-Ala-Thr-Gly-Gln- Pro-Phe-Val-Met-Arg. The enzyme was most active at pH 6.9 and at 64 de grees C, The enzyme was activated slightly by Al3+ and inhibited stron gly by Sn2+ and Zn2+, N-bromosuccinimide, 2-mercaptoethanol, and ethyl enediamine-tetraacetic acid.