Enzymatic conversion of D-galactose to D-tagatose: cloning, overexpression and characterization of L-arabinose isomerase from Pediococcus pentosaceus PC-5.
The gene encoding L-arabinose isomerase from food-grade strain Pediococcus pentosaceus PC-5 was cloned and overexpressed in Escherichia coli. The recombinant protein was purified and characterized. It was optimally active at 50 °C and pH 6.0. Furthermore, this enzyme exhibited a weak requirement for metallic ions for its maximal activity evaluated at 0.6 mM Mn(2+) or 0.8 mM Co(2+). Interestingly, this enzyme was distinguished from other L-AIs, it could not use L-arabinose as its substrate. In addition, a three-dimensional structure of L-AI was built by homology modeling and L-arabinose and D-galactose were docked into the active site pocket of PPAI model to explain the interaction between L-AI and its substrate. The purified P. pentosaceus PC-5 L-AI converted D-galactose into D-tagatose with a high conversion rate of 52% after 24 h at 50 °C, suggesting its excellent potential in D-tagatose production.
National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Yan
Y
Men
National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Yueming
Y
Zhu
National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Lili
L
Zhang
Shanxi Tianjiao Biological Co., Ltd, Shanxin 030006, China.
Zhenkui
Z
Kang
National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Ken
K
Izumori
National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China. Electronic address: syx0430@hotmail.com.
Yuanxia
Y
Sun
National Engineering Laboratory for Industrial Enzymes, Tianjin Institute of Industrial Biotechnology, Chinese Academy of Sciences, Tianjin 300308, China.
Yanhe
Y
Ma
D019747:Aldose-Ketose Isomerases / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D000595:Amino Acid Sequence; D001426:Bacterial Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D055162:Biocatalysis; D020134:Catalytic Domain; D003001:Cloning, Molecular; D004795:Enzyme Stability; D005690:Galactose / Q000737:chemistry*; D006601:Hexoses / Q000737:chemistry*; D062105:Molecular Docking Simulation; D008969:Molecular Sequence Data; D010376:Pediococcus / Q000737:chemistry / Q000201:enzymology* / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment; D013379:Substrate Specificity
D001426:Bacterial Proteins; D006601:Hexoses; D011994:Recombinant Proteins; D019747:Aldose-Ketose Isomerases; C019715:L-arabinose isomerase; C030192:tagatose; D005690:Galactose
Food-grade microorganisms; Pediococcus pentosaceus; d-Tagatose; l-Arabinose isomerase