H. Yanase et al., PURIFICATION, CRYSTALLIZATION, AND CHARACTERIZATION OF THE EXTRACELLULAR INVERTASE FROM ZYMOMONAS-MOBILIS, Journal of fermentation and bioengineering, 79(4), 1995, pp. 367-369
Zymomonas mobilis IFO 13756 (ATCC 29191) produces three kinds of sucro
se-hydrolyzing enzymes, E1, E2, and E3. Extracellular enzymes E2 and E
3 bound to the cell surface were released from cells by suspension in
20 mM potassium phosphate buffer (pH 7.0) and incubation at 30 degrees
C for 10 min with gentle shaking. After centrifugation of the cell su
spension, E3 was isolated from the supernatant as crystals in a 52-fol
d purification. The enzyme consisted of a monomer subunit having a mol
ecular mass of 58 kDa and its isoelectric point was pH 3.2. The N-term
inal amino acid sequence was MFNFNASRWTRAQAMKVNKFDL. The enzyme cataly
zed the hydrolysis of sucrose, and was identified as an invertase that
had a strict substrate specificity for sucrose. The optimum pH and te
mperature were pH 5.5 and 50 degrees C, respectively. Thiol reagents i
nhibited the enzyme activity markedly.