Enzymatic characterization of a maltogenic amylase from Lactobacillus gasseri ATCC 33323 expressed in Escherichia coli.
A gene corresponding to a maltogenic amylase (MAase) in Lactobacillus gasseri ATCC 33323 (lgma) was cloned and expressed in Escherichia coli. The recombinant LGMA was efficiently purified 24.3-fold by one-step Ni-NTA affinity chromatography. The final yield and specific activity of the purified recombinant LGMA were 68% and 58.7 U/mg, respectively. The purified enzyme exhibited optimal activity for beta-CD hydrolysis at 55 degrees C and pH 5. The relative hydrolytic activities of LGMA to beta-CD, soluble starch or pullulan was 8:1:1.9. The activity of LGMA was strongly inhibited by most metal ions, especially Zn(2+), Fe(2+), Co(2+) and by EDTA. LGMA possessed some unusual properties distinguishable from typical MAases, such as being in a tetrameric form, having hydrolyzing activity towards the alpha-(1,6)-glycosidic linkage and being inhibited by acarbose.
Oh
Ko-Woon
KW
Department of Food Science and Biotechnology, Institute of Life Sciences and Resources, KyungHee University, Yongin 449-701, South Korea.
Kim
Myo-Jeong
MJ
Kim
Hae-Yeong
HY
Kim
Byung-Yong
BY
Baik
Moo-Yeol
MY
Auh
Joong-Hyuck
JH
Park
Cheon-Seok
CS
D003001:Cloning, Molecular; D004926:Escherichia coli / Q000201:enzymology* / Q000235:genetics; D006026:Glycoside Hydrolases / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D006868:Hydrolysis; D007778:Lactobacillus / Q000201:enzymology* / Q000235:genetics; D008320:Maltose / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D013379:Substrate Specificity
D011994:Recombinant Proteins; D008320:Maltose; D006026:Glycoside Hydrolases; C120909:glucan 1,4-alpha-maltohydrolase