Purification and characterization of a novel α-glucosidase from Malbranchea cinnamomea.
OBJECTIVE
To characterize a novel α-glucosidase from the thermophilic fungus Malbranchea cinnamomea.


RESULTS
The enzyme was purified to homogeneity with purification fold of 40 and a recovery of 7.2 %. It was a monomer with molecular mass of 65.7 kDa on SDS-PAGE. It was optimally active at pH 6 and 50 °C (measured over 10 min) and exhibited a wide range of substrate specificity with the highest specific activity of 47.4 U mg(-1) for p-nitrophenyl α-D-glucopyranoside (pNPGlu) followed by isomaltose, panose and sucrose, suggesting that the enzyme belongs to the type I α-glucosidases. The K m values of the α-glucosidase for pNPGlu and isomaltose were 1.1 and 19.3 mM, respectively.


CONCLUSIONS
Because of its unique properties, the α-glucosidase may have a potential in several industrial applications.
Bioresource Utilization Laboratory, College of Engineering, China Agricultural University, Beijing, China.
Q J
QJ
Yan
P
P
Han
S Q
SQ
Yang
Z Q
ZQ
Jiang
D000595:Amino Acid Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D005936:Glucans / Q000378:metabolism; D005960:Glucosides / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D007534:Isomaltose / Q000378:metabolism; D007700:Kinetics; D008970:Molecular Weight; D020036:Onygenales / Q000201:enzymology*; D013379:Substrate Specificity; D013395:Sucrose / Q000378:metabolism; D013696:Temperature; D000520:alpha-Glucosidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*
D005936:Glucans; D005960:Glucosides; C008763:panose; C019502:4-nitrophenyl alpha-glucoside; D013395:Sucrose; D007534:Isomaltose; D000520:alpha-Glucosidases