I. Kimura et al., PURIFICATION AND CHARACTERIZATION OF AN ENDO-1,4-BETA-D-GALACTANASE FROM ASPERGILLUS-SOJAE, Journal of fermentation and bioengineering, 85(1), 1998, pp. 48-52
An endo-1,4-beta-D-galactanase (EC 3.2.1.89) was purified to homogenei
ty from a solid-state culture of Aspergillus sojae. The molecular weig
ht of the galactanase was estimated to be 39,700 by sodium dodecyl sul
fate-polyaclylamide gel electrophoresis (SDS-PAGE). Gel filtration chr
omatography indicated the native enzyme to be a monomer. The isoelectr
ic point of the galactanase was 3.60. The optimum pH and temperature o
f the enzyme activity were 4.5 and 50 degrees C, respectively. The gal
actanase was stable from pH 6.0 to 10.0, and up to 35 degrees C. The K
-m value for arabinogalactan from soybean was 0.82 mg/ml. The activity
of the enzyme was significantly inhibited by Mn2+, Hg2+, Ag+, and Fe3
+, and no stimulation by metal ions was apparent. After the hydrolysis
of arabinogalactan from soybean, the major products were galactobiose
and galactose, and no liberation of arabinose was observed in the rea
ction mixture.