[Purification and properties of endoinulinase from Chaetomium sp].
An endoinulinase produced by Chaetomium sp. C34 was purified to electrophoretic homogeneity, with recovery of 7.7% activity and purification factor of 30.8 fold by five steps including ammonium sulfate precipitation, DEAE-cellulose, Q-sepharose Fast Flow, Sephacryl S-200 and Pre-Packed Hydrophobic Column. Its subunit molecular weight was estimated to be about 66kD by SDS-PAGE. The optimum temperature and pH of the enzyme activity were 50 approximately 55 degrees C and 6.0 respectively. The K(m) and V(max) values for inulin were 0.199 mmol/L and 115 micromol/(mg x min) respectively. Cu2+ completely inhibited inulinase activity. An appreciable loss of activity was observed in presence of NBS, Mn2+, Zn2+, Fe2+ and EDTA. A ratio of inulinase activity to invertase activity (I/S) of 20 was found in purified inulinase. The endoinulinase hydrolyzed inulin and liberated inulooligosaccharides. But it lacked activity toward melezitose or raffinose.
Zhang
Guo-Qing
GQ
Institute of Microbiology, Chinese Academy of Sciences, Beijing 100080, China.
Cui
Fu-Mian
FM
Yang
Xiu-Qing
XQ
Qian
Shi-Jun
SJ
D002597:Chaetomium / Q000201:enzymology*; D006026:Glycoside Hydrolases / Q000302:isolation & purification* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D013696:Temperature
D006026:Glycoside Hydrolases; C023086:inulinase