Byung-Hoo Lee
Sejong University
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Featured researches published by Byung-Hoo Lee.
New Biotechnology | 2009
Byung-Hoo Lee; Deok-Kun Oh; Sang-Ho Yoo
A putative 4-alpha-glucanotransferase (alphaGTase) gene from Synechocystis sp. PCC 6803 was identified being composed of 1505 nucleotides, and the overexpressed protein was purified with an affinity chromatography. The recombinant alphaGTase had about 57kDa of molecular mass when judged by SDS-PAGE analysis. The optimum reaction condition of the alphaGTase was shown to be pH 7 at 45 degrees C in 50mm phosphate buffer. This enzyme displayed transglycosylating activity on various maltooligosaccharides, of which the smallest donor and acceptor molecules were determined to be maltose and glucose, respectively. Various corn starches consisting of different proportions of amylopectin and amylose were incubated with the recombinant alphaGTase. The change in molecular weight distribution of alphaGTase-modified starch was analyzed by HPSEC. The reaction pattern of alphaGTase showed substantial decrease in amylopectin and increase in the peak corresponding to cycloamylose (CA). The production yield of CA tended to increase from 5 to 30% along with the increase in the apparent amylose content in corn starch, which suggested that linear amylose chain would be preferred to produce CA in the alphaGTase treatment. The detectable minimum degree of polymerization (DP) of CA was shown to be 22 by MALDI-TOF-MS analysis. As another action mode of alphaGTase, the rearrangement of amylopectin branch-chain distribution occurred without hydrolysis to small oligosaccharides. After isoamylolysis, alphaGTase-treated starch displayed the increase in DP 4-9 and longer than DP 21 when the relative proportion of branch chains in amylopectin was determined by HPAEC.
Journal of Agricultural and Food Chemistry | 2016
Byung-Hoo Lee; David R. Rose; Amy Hui-Mei Lin; Roberto Quezada-Calvillo; Buford L. Nichols; Bruce R. Hamaker
The mammalian mucosal α-glucosidase complexes, maltase-glucoamylase (MGAM) and sucrase-isomaltase (SI), have two catalytic subunits (N- and C-termini). Concurrent with the desire to modulate glycemic response, there has been a focus on di-/oligosaccharides with unusual α-linkages that are digested to glucose slowly by these enzymes. Here, we look at disaccharides with various possible α-linkages and their hydrolysis. Hydrolytic properties of the maltose and sucrose isomers were determined using rat intestinal and individual recombinant α-glucosidases. The individual α-glucosidases had moderate to low hydrolytic activities on all α-linked disaccharides, except trehalose. Maltase (N-terminal MGAM) showed a higher ability to digest α-1,2 and α-1,3 disaccharides, as well as α-1,4, making it the most versatile in α-hydrolytic activity. These findings apply to the development of new glycemic oligosaccharides based on unusual α-linkages for extended glycemic response. It also emphasizes that mammalian mucosal α-glucosidases must be used in in vitro assessment of digestion of such carbohydrates.
Journal of Agricultural and Food Chemistry | 2016
Dong-Wan Koh; Min-Oh Park; Seong-Won Choi; Byung-Hoo Lee; Sang-Ho Yoo
A novel enzymatic process for cyclodextrin (CD) production was developed by utilizing sucrose as raw material instead of corn starch. Cyclodextrin glucanotransferase (CGTase) from Bacillus macerans was applied to produce the CDs from linear α-(1,4)-glucans, which were obtained by Neisseria polysaccharea amylosucrase (NpAS) treatment on sucrose. The greatest CD yield (21.1%, w/w) was achieved from a one-pot dual enzyme reaction at 40 °C for 24 h. The maximum level of CD production (15.1 mg/mL) was achieved with 0.5 M sucrose in a simultaneous mode of dual enzyme reaction, whereas the reaction with 0.1 M sucrose was the most efficient with regard to conversion yield. Consequently, dual enzyme synthesis of CDs was successfully carried out with no need of starch material. This result can be applied as a novel efficient bioconversion process that does not require the high temperature necessary for starch liquefaction by thermostable α-amylase in conventional industrial processing.
Journal of Agricultural and Food Chemistry | 2016
Min-Oh Park; Byung-Hoo Lee; Eunjin Lim; Ji Ye Lim; Yuri Kim; Cheon-Seok Park; Hyeon Gyu Lee; Hee-Kwon Kang; Sang-Ho Yoo
Turanose is a sucrose isomer naturally existing in honey and a promising functional sweetener due to its low glycemic response. In this study, the extrinsic fructose effect on turanose productivity was examined in Neisseria amylosucrase reaction. Turanose was produced, by increasing the amount of extrinsic fructose as a reaction modulator, with high concentration of sucrose substrate, which resulted in 73.7% of production yield. In physiological functionality test, lipid accumulation in 3T3-L1 preadipocytes in the presence of high amounts of pure glucose was attenuated by turanose substitution in a dose-dependent manner. Turanose treatments at concentrations representing 50%, 75%, and 100% of total glucose concentration in cell media significantly reduced lipid accumulation by 18%, 35%, and 72%, respectively, as compared to controls. This result suggested that turanose had a positive role in controlling adipogenesis, and enzymatic process of turanose production has a potential to develop a functional food ingredient for controlling obesity and related chronic diseases.
Starch-starke | 2010
Je-Hoon Ryu; Byung-Hoo Lee; Dong-Ho Seo; Moo-Yeol Baik; Cheon-Seok Park; Ren Wang; Sang-Ho Yoo
Food Hydrocolloids | 2009
Sang-Ho Yoo; Byung-Hoo Lee; Brett J. Savary; Suyong Lee; Hyeon Gyu Lee; Arland T. Hotchkiss
Food Science and Biotechnology | 2009
Je-Hoon Ryu; Dong-Hyung Yoo; Byung-Hoo Lee; Suyong Lee; Mi Hyun Joo; Sang-Ho Yoo
Journal of Microbiology and Biotechnology | 2008
Byung-Hoo Lee; Young-Hee Yoo; Je-Hoon Ryu; Tae-Jip Kim; Sang-Ho Yoo
Journal of Pediatric Gastroenterology and Nutrition | 2018
Byung-Hoo Lee; Bruce R. Hamaker
CFW Plexus | 2013
Bruce R. Hamaker; Amy Lin; Byung-Hoo Lee; Like Y. Hasek; Choon Young Kim; Fatima Cisse; Beth Pietsch