Jae-Hoon Shim

Hallym University, Sŏul, Seoul, South Korea

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Publications (41)84.58 Total impact

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    ABSTRACT: Cyclodextrin glucanotransferase (CGTase; EC mainly produces cyclodextrins (CDs) using linear maltooligosaccharides. We performed site-directed saturation mutagenesis on the +1 substrate-binding residue, H233, of CGTase from alkalophilic Bacillus sp. I-5 to prepare specific-length oligosaccharides. The obtained mutant CGTase, H233Y, primarily produced maltoheptaose (G7) using β-CD via a hydrolysis reaction. A kinetic study of H233Y showed that the kcat/Km value of β-CD was 7-fold greater than that of G7, which accounts for the accumulation of G7 during the H233Y enzyme reaction. A structure comparison of CGTases with H233Y modeling suggests that the substitution of H233Y may alter the position of the +1 subsite and slow the further hydrolysis of G7 after the ring-opening reaction.
    Protein Engineering Design and Selection 09/2015; DOI:10.1093/protein/gzv044 · 2.54 Impact Factor
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    ABSTRACT: In this study, we investigated the anti-diabetic effect of Aster sphathulifolius (AS) extract in C57BL/KsJ-db/db mice. The db/db mice were orally administered with AS 50% ethanol extract at concentrations of 50, 100, and 200 mg/kg/day (db/db-AS50, db/db-AS100, and db/db-AS200, respectively) for 10 weeks. Food and water intake, fasting blood glucose concentrations, blood glycosylated hemoglobin levels, and plasma insulin levels were significantly lower in the db/db-AS200 group than in the vehicle-treated db/db group; whereas glucose tolerance was significantly improved in the db/db-AS200 group. Moreover, AS dose dependently increased both insulin receptor substrate 1 and glucose transporter type 4 expression in skeletal muscle, significantly increased glucokinase expression, and decreased glucose 6-phosphatase and phosphoenolpyruvate carboxykinase expressions in the liver. The expressions of transcription factors, such as sterol-regulatory element-binding protein, peroxisome proliferator-activated receptor γ, and adipocyte protein 2, were upregulated in adipose tissue. Furthermore, immunohistochemical analysis showed that AS upregulated insulin production by increasing pancreatic β-cell mass. In summary, AS extract normalized hyperglycemia by multiple mechanisms: inhibition of glyconeogenesis, acceleration of glucose metabolism and lipid metabolism, and increase of glucose uptake. Using in vivo assays, this study has shown the potential of AS as a medicinal food and suggests the efficacy of AS for the use of prevention of diabetes.
    Journal of medicinal food 05/2015; 18(9). DOI:10.1089/jmf.2014.3416 · 1.63 Impact Factor
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    ABSTRACT: The efficacy of Aster sphathulifolius (AS) for evaluation of preventive potencies against diabetes and diabetic complications was analyzed by assessment of inhibitory effects against advanced glycation end-products (AGEs) formation, rat lens aldose reductase (RLAR), α-glucosidase activity, and scavenging effects against DPPH. The 50% ethanol extract showed the highest DPPH radical scavenging activity (82.38%) at a concentration of 100 μg/mL, exhibited the most potent AGEs formation inhibitory effect (93.88%) at a concentration of 200 μg/mL, showed the most potent RLAR inhibitory effect (86.44%) at a concentration of 11.11 μg/mL. The 95% ethanol extract showed a potent α-glucosidase inhibitory activity (19.16%) at a concentration of 1 mg/mL. The 50% ethanol extract value was 16.79%. The 50% ethanol extract exhibited the most potent antioxidant and preventive actions against diabetes and diabetic complications and can, thus, be a source of valuable compounds for prevention of diabetes and diabetic complications.
    Food science and biotechnology 02/2015; 24(1). DOI:10.1007/s10068-015-0040-0 · 0.65 Impact Factor
  • Hyeyeon Jeon · Hyewon Lee · Dahye Byun · Hyejeong Choi · Jae-Hoon Shim ·
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    ABSTRACT: A novel hyperthermostable α-glucosidase from the hyperthermophilic archaeon Pyrobaculum aerophilum str. IM2 (PAE1968) was successfully expressed in Escherichia coli and characterized. Recombinant PAE1968 was purified using Ni-NTA affinity chromatography to reveal a glycosidase with a predicted molecular weight (Mw) of 76 kDa. PAE1968 liberated glucose from the non-reducing ends of oligosaccharides. Multiple sequence alignment confirmed that the enzyme belonged to glycoside hydrolase (GH) family 31, and a kinetic study showed that the enzyme had a substrate preference for maltose (G2), indicating a Type-II α-glucosidase. The optimum operating conditions for the enzyme were 90°C and pH 6.0, while the enzyme retained at least 80% of maximal activity at pH 4.5–7.5. Transglycosylation and reversion reactions of PAE1968 were of a lower magnitude than for a commercial saccharification enzyme, indicating that this enzyme can be used for glucose production in the starch industry.
    Food science and biotechnology 02/2015; 24(1). DOI:10.1007/s10068-015-0024-0 · 0.65 Impact Factor
  • Xing Fu Yin · Young Eun Jeon · Jae-Hoon Shim · Il-Jun Kang ·
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    ABSTRACT: The efficacy of Ligularia fischeri (LF) for managing diabetic complications was evaluated by assessing inhibitory effects against advanced glycation end product (AGE) formation, rat lens aldose reductase (RLAR), and 1,1-diphenyl-2-picryl hydrazyl (DPPH) radical scavenging. The ethyl acetate fraction from 70% ethanol extracts of LF showed the highest DPPH radical scavenging activity of 53.90% at a concentration of 3.3 μg/mL. The ethyl acetate fraction exhibited the most potent AGE formation inhibition of 73.57% at a concentration of 55 μg/mL and showed the most potent RLAR inhibition of 88.97% at a concentration of 11.11 μg/mL. The ethyl acetate fraction exhibited the most potent antioxidant and anti-diabetic effects. Nuclear magnetic resonance via bioactivity-guided fractionation of the LF ethyl acetate fraction revealed that 3,4-dicaffeoylquinic acid was the bioactive compound. This compound from LF can be effective for prevention or treatment of diabetic complications.
    Food science and biotechnology 12/2014; 23(6). DOI:10.1007/s10068-014-0239-5 · 0.65 Impact Factor
  • Hye-Won Lee · Hye-Yeon Jeon · Hyejeong Choi · Jae-Hoon Shim ·
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    ABSTRACT: To enzymatically prepare amylopectin cluster (APC), cyclodextrin glucanotransferase (CGTase I-5) and its mutant enzyme from alkalophilic Bacillus sp. I-5 were employed, after which the hydrolysis patterns of CGTase wild-type and its mutant enzyme toward amylopectin were investigated using multi-angle laser light scattering. CGTase wild-type dramatically reduced the molecular weight of waxy rice starch at the initial reaction, whereas the mutant enzyme degraded waxy rice starch relatively slowly. Based on the results, the molecular weight of one cluster of amylopectin could be about 104 ~ 105 g/mol. To determine production of cyclic glucans from amylopectin, matrix-assisted laser desorption ionization time-of-flight mass spectrometry was performed. CGTase I-5 produced various types of cyclic maltooligosaccharides from amylopectin, whereas the mutant enzyme hardly produced any. © 2014, Korean Society of Food Science and Nutrition. All rights reserved.
    Journal of the Korean Society of Food Science and Nutrition 09/2014; 43(9):1388-1393. DOI:10.3746/jkfn.2014.43.9.1388
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    ABSTRACT: We studied the activity of a debranching enzyme (TreX) from Sulfolobus solfataricus on glycogen-mimic substrates, branched maltotetraosyl-β-cyclodextrin (Glc4-β-CD), and natural glycogen to better understand substrate transglycosylation and the effect thereof on glycogen debranching in microorganisms. The validation test of Glc4-β-CD as a glycogen mimic substrate showed that it followed the breakdown process of the well-known yeast and rat liver extract. TreX catalyzed both hydrolysis of α-1,6-glycosidic linkages and transglycosylation at relatively high (>0.5 mM) substrate concentrations. TreX transferred maltotetraosyl moieties from the donor substrate to acceptor molecules, resulting in the formation of two positional isomers of dimaltotetraosyl-α-1,6-β-cyclodextrin [(Glc4)2-β-CD]; these were 61,63- and 61,64-dimaltotetraosyl-α-1,6-β-CD. Use of a modified Michaelis-Menten equation to study substrate transglycosylation revealed that the kcat and Km values for transglycosylation were 1.78 × 103 s−1 and 3.30 mM, respectively, whereas the values for hydrolysis were 2.57 × 103 s−1 and 0.206 mM, respectively. Also, enzyme catalytic efficiency (the kcat/Km ratio) increased as the degree of polymerization of branch chains rose. In the model reaction system of Escherichia coli, glucose-1-phosphate production from glycogen by the glycogen phosphorylase was elevated ∼1.45-fold in the presence of TreX compared to that produced in the absence of TreX. The results suggest that outward shifting of glycogen branch chains via transglycosylation increases the number of exposed chains susceptible to phosphorylase action. We developed a model of the glycogen breakdown process featuring both hydrolysis and transglycosylation catalyzed by the debranching enzyme.
    Journal of bacteriology 03/2014; 196(11). DOI:10.1128/JB.01442-13 · 2.81 Impact Factor
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    ABSTRACT: A brewing process for rice-grape wine, in which rice powder and grapes are concurrently fermented, was developed. Rice powder was mixed with α-glucosidase, glucose isomerase, and yeast, and then incubated for 2 days at 25°C. Then a mixture of ‘Muscat Baily A’ and ‘Campbe Early’ grape must was added to the fermented mixture of rice and maintained at 4°C to allow for complete ethanol fermentation. The rice-grape wine contained 11.6% ethanol, compared to 9.6% ethanol for grape wine. The aroma profile revealed that 2-methyl-1-propanol, 2-methyl propyl acetate, and phenethyl acetate were in greater abundance in the rice-grape wine, whereas ethyl hexanoate, diethyl succinate, and ethyl decanoate were more abundant in the grape wine. The esters formed from fatty acids and ethanol increased during 2 years of storage for both wines. An electronic nose analysis revealed no significant difference in the aromas of the rice-grape and grape wine samples.
    Food science and biotechnology 08/2013; 22(4). DOI:10.1007/s10068-013-0167-9 · 0.65 Impact Factor
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    ABSTRACT: Erythorbyl laurate was continuously synthesized by esterification in a packed-bed enzyme reactor with immobilized lipase from Candida antarctica. Response surface methodology based on a five-level three-factor central composite design was adopted to optimize conditions for the enzymatic esterification. The reaction variables, such as reaction temperature (10-70°C), substrate molar ratio ([lauric acid]/[erythorbic acid], 5-15), and residence time (8-40 min) were evaluated and their optimum conditions were found to be 56.2°C, 14.3, and 24.2 min, respectively. Under the optimum conditions, the molar conversion yield was 83.4%, which was not significantly different (P < 0.05) from the value predicted (84.4%). Especially, continuous water removal by adsorption on an ion-exchange resin in a packed-bed enzyme reactor improved operational stability, resulting in prolongation of half-life (2.02 times longer compared to the control without water-removal system). Furthermore, in the case of batch-type reactor, it exhibited significant increase in initial velocity of molar conversion from 1.58% to 2.04%/min. © 2013 American Institute of Chemical Engineers Biotechnol. Prog., 2013.
    Biotechnology Progress 07/2013; 29(4):882-889. DOI:10.1002/btpr.1745 · 2.15 Impact Factor
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    ABSTRACT: Structural modification of rice and barley starches with Neisseria polysaccharea amylosucrase (NpAS) was conducted, and relationship between structural characteristics and resistant starch (RS) contents of NpAS-treated starches was investigated. Pre-gelatinised rice and barley starches were treated with NpAS. NpAS-treated starches were characterised with respect to morphology, X-ray diffraction pattern, amylopectin branch-chain distribution, and RS content, and their structural characteristics were correlated to RS contents. Regardless of amylose contents of native starches, NpAS-treated (relative to native) starches possessed lower and higher proportions of shorter (DP 6-12) and intermediate (DP 13-36) amylopectin (AP) branch-chains, respectively. RS contents were higher for NpAS-treated starches relative to native starches, and maximum RS contents were obtained for NpAS-treated starches of waxy rice and barley genotypes. Amylose contents were not associated with RS contents of NpAS-treated starches. However, shorter and intermediate AP branch-chain portions were negatively and positively correlated to RS contents of NpAS-treated starches, respectively.
    Food Chemistry 06/2013; 138(2-3):966-75. DOI:10.1016/j.foodchem.2012.11.028 · 3.39 Impact Factor
  • Soojung Heo · Seung Mi Lee · Jae-Hoon Shim · Sang-Ho Yoo · Suyong Lee ·
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    ABSTRACT: The rheological and cooking properties of gluten-free noodles prepared with dry- and wet-milled rice flours were characterized. Dry-milled rice flour with a higher degree of starch damage exhibited greater water hydration properties than wet-milled rice flour at room temperature. However, the pasting results of rice flour suspensions demonstrated that wet-milled rice flour showed a higher value of peak viscosity due to its great swelling power upon starch gelatinization. The similar thermo-mechanical tendency was observed in a rice dough system by Mixolab. In the planar extensional test, the noodle dough sample prepared with dry-milled rice flour exhibited higher elongational viscosity which could be favorably correlated to more resistance of dry-milled rice noodle strands to extension. When rice noodles were cooked, increased cooking loss was observed in dry-milled rice noodles which was attributed to great water solubility derived from a higher degree of starch damage.
    Journal of Food Engineering 05/2013; 116(1):213–217. DOI:10.1016/j.jfoodeng.2012.11.017 · 2.77 Impact Factor
  • Jae-Hoon Shim · Stephen G. Withers ·
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    ABSTRACT: To achieve high level expression of β-glucosidase from Agrobacterium sp. (Abg) in an Escherichia coli expression system, 6 rare codons at +3, +11, +158, +308, +314, and +318 of abg gene were replaced with favored codons using site-directed mutagenesis. The rare codon replacements of +3 (CCC) and +11 (CCC) positions enhanced the expression level of Abg by 2- and 3.6-fold, respectively. The double mutant, Abg-DM, where both of +3 and +11 rare codon positions were modified showed a 5.2-fold higher expression level than the original abg gene. Circular dichroism (CD) spectra of the over-expressed Abg and original Abg enzymes were identical, indicating that Abg was properly folded during over-expression.
    Food science and biotechnology 02/2013; 22(1). DOI:10.1007/s10068-013-0036-6 · 0.65 Impact Factor
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    ABSTRACT: We investigated the acute metabolic effects of isoflavones from Pueraria lobata (Willd.) Ohwi (IPL) in ovariectomized (OVX) mice. After 4 weeks of IPL feeding at 500 mg/day/kg body weight (OVX500), plasma 17β-estradiol concentrations were significantly higher (+25%, p < 0.05), whereas plasma triglyceride levels were significantly lower in OVX mice (-15%, p < 0.05) compared with controls. Abdominal adipose tissue weight was marginally reduced in IPL-fed groups compared with OVX controls and the plasma levels of liver enzymes were unchanged. In addition, IPL significantly inhibited the reduction of bone mineral density in the femurs of OVX mice (OVX200, +22%; OVX500, +26%; p < 0.05) compared with controls after 4 weeks of IPL feeding. In quantitative polymerase chain reaction analysis the expression of aromatase was significantly suppressed and SULT1E1 was increased by IPL feeding, showing that IPL feeding may not alter the risk for breast cancer in mice. Our results suggest that IPL could ameliorate menopausal symptoms in mice. Further studies will confirm the effects of IPL in humans. Copyright © 2012 John Wiley & Sons, Ltd.
    Phytotherapy Research 12/2012; 26(12). DOI:10.1002/ptr.4669 · 2.66 Impact Factor
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    Xing Fu Yin · Young Eun Jeon · Tae-Keun Kim · Jae-Hoon Shim · Il-Jun Kang ·
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    ABSTRACT: This study was conducted to evaluate the possible subacute toxicity of gamma-irradiated Tarakjuk. Tarakjuk was irradiated at a dose of 30 kGy at room temperature. For the animal study, AIN-93G as a control diet and 30 kGy irradiated and non-irradiated Tarakjuk diets were administered to male and female ICR mice (10 mice per group) for 3 months. During the experimental period, the group fed 30 kGy irradiated Tarakjuk did not show any changes in appearance, behavior, mortality, body weight, organ weight, or food consumption compared to control. Further, all biochemical parameters were in normal ranges. In the histopathological examination of liver and kidney tissues of ICR mice, there were no significant differences between the control and 30 kGy irradiated Tarakjuk groups. These results indicate that Tarakjuk irradiated at 30 kGy did not cause any toxic effects under these experimental conditions.
    Journal of the Korean Society of Food Science and Nutrition 11/2012; 41(11). DOI:10.3746/jkfn.2012.41.11.1534
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    Hwan-Ung Yong · Seonmi Kim · Jae-Hoon Shim ·
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    ABSTRACT: Alkyl glucosides were synthesized using the transglycosylation reaction of Celluclast, the cellulase from Trichoderma reesei, with cellobiose and various alcohols. Glucose as a by-product of the reaction was removed using the immobilized yeast system. Among the alkyl glucoside products, the acceptor products of methanol and ethanol were confirmed as methyl -D-glucopyranoside and ethyl -D-glucopyranoside via MALDI-TOF MS and enzymatic analysis. Optimal yields of methyl -glucoside and ethyl -glucoside were 65.3% (mol/mol) and 59.0% (mol/mol), respectively, based on cellobiose consumed.
    Journal of the Korean Society of Food Science and Nutrition 10/2012; 41(10). DOI:10.3746/jkfn.2012.41.10.1417
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    ABSTRACT: Lipid-laden peripheral tissue cells release cholesterol to an extracellular acceptor such as high-density lipoprotein (HDL). Foam cells are formed at the first stage of atherosclerosis development. This study investigated whether sage weed (Salvia plebeia) extract (SWE) influences cholesterol handling of J774A1 murine macrophages. A murine macrophage cell line, J774A1, was used in this study. Oxidized low-density lipoproteins (LDL) treatment was used for foam cell formation, which was confirmed using Oil red O staining. The oxidized LDL uptake and cholesterol efflux from lipid-laden foam cell-associated proteins were detected by western blot analysis. Also, transcriptional levels of these associated genes were examined using reverse transcription-PCR. Also, cholesterol efflux was measured using NBD-cholesterol efflux assay. Non-toxic SWE at ≥10 µg/ml attenuated scavenger receptor (SR)-B1 expression of macrophages induced by oxidized LDL for 6 h, which was achieved at its transcriptional levels. Consistently, SWE suppressed oxidized LDL-stimulated cellular lipid accumulation and foam cell formation due to downregulated SR-B1. SWE upregulated the protein expression and mRNA levels of ATP-binding cassette transporter A1 (ABCA1) and ATP-binding cassette transporter G1 (ABCG1) in lipid-laden foam cells, both responsible for cholesterol efflux. In addition, SWE promoted apolipoprotein E (apoE) secretion from oxidized LDL-induced foam cells. Cholesterol efflux was enhanced by ≥10 µg/ml SWE most likely through the induction of ABCA1 and ABCG1 and the secretion of apoE. Although 10 µM homoplantaginin, a compound mainly present in sage weeds, did not influence cellular expression of ABCA1 and ABCG1, it suppressed oxidized LDL-enhanced SR-B1 induction and foam cell formation. These results demonstrate that SWE antagonized oxidized LDL uptake and promoted cholesterol efflux in lipid-laden macrophages. Therefore, SWE may serve as a protective therapeutic agent against the development of atherosclerosis.
    International Journal of Molecular Medicine 08/2012; 30(5):1105-12. DOI:10.3892/ijmm.2012.1103 · 2.09 Impact Factor
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    ABSTRACT: Glycans bearing modified hydroxyl groups are common in biology but because these modifications are added after assembly, enzymes are not available for the transfer and coupling of hydroxyl-modified monosaccharide units. Access to such enzymes could be valuable, particularly if they can also introduce 'bio-orthogonal tags'. Glycosynthases, mutant glycosidases that synthesize glycosides using glycosyl fluoride donors, are a promising starting point for creation of such enzymes through directed evolution. Inspection of the active site of a homology model of the GH1 Agrobacterium sp. β-glycosidase, which has both glucosidase and galactosidase activity, identified Q24, H125, W126, W404, E411 and W412 as amino acids that constrain binding around the 3-OH group, suggesting these residues as targets for mutation to generate an enzyme capable of handling 3-O-methylated sugars. Site-directed saturation mutagenesis at these positions within the wild-type β-glycosidase gene and screening via an on-plate assay yielded two mutants (Q24S/W404L and Q24N/W404N) with an improved ability to hydrolyze 4-nitrophenyl 3-O-methyl-β-D-galactopyranoside (3-MeOGal-pNP). Translation of these mutations into the evolved glycosynthase derived from the same glucosidase (2F6) yielded glycosynthases (AbgSL-T and AbgNN-T, where T denotes transferase) capable of forming 3-O-methylated glucosides on multi-milligram scales at rates approximately 5 and 40 times greater, respectively, than the parent glycosynthase.
    Protein Engineering Design and Selection 08/2012; 25(9):465-72. DOI:10.1093/protein/gzs045 · 2.54 Impact Factor
  • Je-Hoon Ryu · Suyoung Lee · SangGuan You · Jae-Hoon Shim · Sang-Ho Yoo ·
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    ABSTRACT: In order to understand the relationship between chemical structure and physical properties of cereal β-glucans, the β-glucans with identical Mw (98.4–99.2 kDa) and Rg (21.1–22.0 nm) were isolated from chal and gwangan barley, and ohl oat, and their linkage structure, flow behavior, and thermal properties were investigated. Previously, we established a purification method of 3-O-cellobiosyl-glucose (DP3) and 3-O-cellotriosyl-glucose (DP4) (Yoo, Lee, Chang, Lee, & Yoo, 2007) and applied these authentic standards to quantify the ratio of β-(1,4)/(1,3) linkages in cereal β-glucans. β-Glucans isolated from two barley cultivars had greater proportion of DP3 than did the oat, and within barley cultivars chal barley β-glucan had significantly larger amount of DP3 over gwangan cultivar. Thus, chal barley β-glucan had the greatest molar ratio (2.53) of DP3 to DP4, and ohl oat had the lowest (1.51). While all the β-glucan solutions showed strong shear thinning behavior, ohl oat β-glucan with higher proportion of DP4 exhibited the highest viscosity among the β-glucan samples. After 3 freeze-thaw cycles of 3% (w/v) β-glucan samples, chal barley β-glucan had lower onset (To) and peak (Tp) temperatures (28.3 and 36.7 °C, respectively) than those of gwangan barley (33.6 and 39.9 °C) and ohl oat (37.9 and 46.9 °C) did, and the heat scan profiles were thermoreversible. The To and Tp of inter-chain associations decreased as the DP3:DP4 ratio of the β-glucan increased. From this study, it was suggested that cellotetraosyl units and longer β-(1,4)-linked segments would be a major contributor for improving solution viscosity and gel formation of cereal β-glucans.
    Carbohydrate Polymers 08/2012; 89(4):1238–1243. DOI:10.1016/j.carbpol.2012.04.025 · 4.07 Impact Factor
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    Jae-Hoon Shim · Byung-Chul Oh ·
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    ABSTRACT: The enzyme phytase has broad biotechnological applications, especially in the reduction of phytate, antinutritional factors that chelate essential minerals, in human and animal food. We investigated the enzymatic properties of β-propeller phytase (BPP) from Bacillus amyloliquefaciens DS11. Thermal refolding analysis demonstrated that BPP can remarkably restore its enzymatic activity in the presence of 5 mM Ca(2+) to 87% of its original activity after heating to 100 °C and subsequent cooling, indicating that the enzyme requires Ca(2+) for appropriate refolding. Furthermore, pH-dependent kinetic studies showed that BPP required excess Ca(2+) for its enzymatic activity as the pH decreased, suggesting that the optimal Ca(2+)-phytate ratio for enzymatic catalysis depends on the pH value of the environment. Finally, we verified the practical application of BPP at two different pH's using soybean meal as a natural source of phytate. As compared to a commercial phytase, BPP efficiently hydrolyzed food phytate over neutral pH ranges.
    Journal of Agricultural and Food Chemistry 07/2012; 60(30). DOI:10.1021/jf3022942 · 2.91 Impact Factor
  • Yujeong Kim · Sang-Ho Yoo · Kwan-Hwa Park · Jae-Hoon Shim · Suyong Lee ·
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    ABSTRACT: Native starch samples (corn, rice, and tapioca starches) were prepared in an aqueous slurry and dough system, and their functional properties were evaluated in terms of thermal and rheological characteristics. The pasting property results of starch slurries showed that rice starch exhibited the lowest peak temperature, whereas the highest peak viscosity was observed in tapioca starch. When starch suspensions were subjected to dynamic oscillatory temperature sweep testing, the increased storage moduli and reduced tan δ derived from starch gelatinization were clearly observed in all starch samples, showing that the gelatinized starch granules became more elastic. Steady shear measurements revealed the shear-thinning behaviors of starch pastes, which were dominant in tapioca starch, compared to the other starches. In addition, the distinct endothermic peaks of starch gelatinization were observed at 73.15, 62.25, and 70.55°C for corn, rice, and tapioca starches, respectively and these trends were in good agreement with the pasting and viscoelastic results. However, upon incorporation of the native starches to a wheat dough system, the highest dough consistency during heating and cooling was observed in corn starch probably due to the rigidity of its particle. Thus, the physicochemical response of native starches to temperature appeared to be different in different concentration regimes.
    Journal of the Korean Society for Applied Biological Chemistry 06/2012; 55(3). DOI:10.1007/s13765-012-2002-z · 0.69 Impact Factor

Publication Stats

343 Citations
84.58 Total Impact Points


  • 2010-2015
    • Hallym University
      • Department of Food Science and Nutrition
      Sŏul, Seoul, South Korea
  • 2010-2014
    • University of Incheon
      Sŏul, Seoul, South Korea
  • 2004-2010
    • Seoul National University
      • • College of Agriculture and Life Sciences
      • • Department of Agricultural Biotechnology
      Sŏul, Seoul, South Korea