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Enzymatic synthesis of alkyl glucosides using Leuconostoc mesenteroides dextransucrase.
Kim, Young-Min,Kim, Byung-Hoon,Ahn, Joon-Seob,Kim, Go-Eun,Jin, Sheng-De,Nguyen, Thanh-Hanh,Kim, Doman Kluwer Academic Publishers 2009 Biotechnology letters Vol.31 No.9
<P>Alkyl glucosides were synthesized by the reaction of Leuconostoc mesenteroides dextransucrase with sucrose and various alcohols. Alkyl alpha-D-glucosides were obtained with a yield of 30% (mol/mol) with primary alcohols, but secondary alcohols or tertiary alcohols gave yields below 5%. The optimal yield was 50% using 1-butyl alpha-D-glucoside with 0.9 M 1-butanol. The acceptor products of methanol or ethanol were confirmed as methyl alpha-D-glucopyranoside and ethyl alpha-D: -glucopyranoside via MALDI-TOF MS and NMR analysis. Thus, methyl or ethyl alpha-D-glucoside constituted half the emulsification activities of Triton X-100 as commercially available surfactants.</P>
Kim, Go-Eun,Kang, Hee-Kyoung,Seo, Eun-Seong,Jung, Sun-Hwa,Park, Jun-Seong,Kim, Duck-Hee,Kim, Do-Won,Ahn, Sul-Ah,Sunwoo, Changshin,Kim, Doman Elsevier 2012 Enzyme and microbial technology Vol.50 No.1
<P><B>Graphical abstract</B></P><P></P><ce:figure id='fig0020'></ce:figure> <P><B>Abstract</B></P><P>Astragalin (kaempferol-3-<I>O</I>-β-<SMALL>D</SMALL>-glucopyranoside, Ast) glucosides were synthesized by the acceptor reaction of a dextransucrase produced by <I>Leuconostoc mesenteroides</I> B-512FMCM with astragalin and sucrose. Each glucoside was purified and their structures were assigned as kaempferol-3-<I>O</I>-β-<SMALL>D</SMALL>-glucopyranosyl-(1→3)-<I>O</I>-α-<SMALL>D</SMALL>-glucopyranoside (or kaempferol-3-<I>O</I>-β-<SMALL>D</SMALL>-nigeroside, Ast-G1′) and kaempferol-3-<I>O</I>-β-<SMALL>D</SMALL>-glucopyranosyl-(1→6)-<I>O</I>-α-<SMALL>D</SMALL>-glucopyranoside (or kaempferol-3-<I>O</I>-β-<SMALL>D</SMALL>-isomaltoside, Ast-G1) for one glucose transferred, and kaempferol-3-<I>O</I>-β-<SMALL>D</SMALL>-isomaltooligosacharide (Ast-IMO or Ast-Gn; <I>n</I>=2–8). The astragalin glucosides exhibited 8.3–60.6% higher inhibitory effects on matrix metalloproteinase-1 expression, 18.8–20.3% increased antioxidant effects, and 3.8–18.8% increased inhibition activity of melanin synthesis compared to control (without the addition of compound), depending on the number of glucosyl residues linked to astragalin. These novel compounds could be used to further expand the industrial applications of astragalin glucosides, in particular in the cosmetics industry.</P>
Glucanhydrolase from Lipomyces starkeyi KSM 22 as Potential Mouthwash Ingredient
KIM, DOMAN,RYU, SU-JIN,SON, EUN-JU,CHUNG, HYUN-JU,KIM, SEUNG-HEUK,KIM, DO-WON,DAY, DONAL F. 한국미생물 · 생명공학회 2002 Journal of microbiology and biotechnology Vol.12 No.6
A glucanhydrolase (a DXAMase exhibiting both dextranolytic and amylolytic activities) from Lipomyces starkeyi KSM 22 hydrolyzed polysaccharides having α-(1→3)-, α-(1→4)-, and α-(1→6)-D-glucosidic likages. The oral hygiene benefits of DXAMase-containing mouthwash were examined in relation to human experimental gingivitis during a 3-week period without brushing. The DXAMase-treated group exhibitied a lower increase in plaque accumulation and gingival index score than the chlorhexidine-treated group. The DXAMase-treated group also showed less tongue accumulation, had taste, and tooth staining, thus indicating a positive role for DXAMase as an antiplaque agent ingredient.
Cell Death and Intracellular Distribution of Hematoporphyrin in a KB Cell Line
Choi, Hongran,Lim, Wonbong,Kim, Ji-Eun,Kim, Inae,Jeong, Jinan,Ko, Youngjong,Song, Jongwoon,You, Sunyeol,Kim, Doman,Kim, Misook,Kim, Byung-Kuk,Kim, Okjoon Mary Ann Liebert 2009 Photomedicine and laser surgery Vol.27 No.3
<P>OBJECTIVE: The objective of this study is to investigate the effect of intracellular photosensitizer distribution on tumor cell death after photodynamic therapy (PDT). BACKGROUND DATA: The photosensitizer accumulates in tumor tissue during PDT, and generates intracellular reactive oxygen species (ROS), resulting in tumor cell death. MATERIALS AND METHODS: This study was carried out to elucidate the effects of PDT in a KB oral cancer cell line using hematoporphyrin with irradiation at 635 nm and 5 mW/cm(2). After irradiation, the MTT reduction method, agarose gel electrophoresis, flow cytometry, and Diff-Quick staining were performed. The intracellular ROS level was measured by DCF-DA. Intracellular hematoporphyrin was monitored with a confocal microscope, and Western blot and caspase activity assays were performed. RESULTS: In our study, cell survival was reduced by about 50% after 3 h of hematoporphyrin incubation time. In DNA fragmentation, flow cytometry, and Diff-Quick assay, necrosis was identified within 12 h and apoptosis soon thereafter. Confocal microscopy revealed that hematoporphyrin was localized in the cell membrane, cytoplasm, and nucleus as time passed. The quantities of intracellular ROS correlated with the time of hematoporphyrin accumulation. Additionally, Western blot analysis of Bcl-2/Bax, the release of cytochrome C, and activity of caspase-3 and caspase-9 showed that apoptosis followed the mitochondria-dependent pathway. CONCLUSION: PDT with hematoporphyrin in the KB cell line showed morphological changes of cell necrosis and apoptosis, which were associated with the time of distribution and localization of hematoporphyrin. Also, the apoptosis evoked followed the mitochondria-dependent pathway.</P>
Production of Maltopentaose and Biochemical Characterization of Maltopentaose-Forming Amylase
KIM, YOUNG-MIN,RUY, HWA-JA,LEE, SUN-OK,SEO, EUN-SEONG,LEE, SO-YOUNG,YOO, SUM-KYUN,CHO, DONG-LYUN,KIM, DOMAN,ATSUO KIMURA,SEIYA CHIBA,LEE, JIN-HA 한국미생물 · 생명공학회 2001 Journal of microbiology and biotechnology Vol.11 No.4
Bacillus sp. AIR-5, a strain from soil, produced an extracellular maltohentaose-forming amylase from amylose and soluble starch. This bacterium produced 8.9g/l of maltopentaose from 40g/l of soluble starch in a batch fermentation and the maltopentaose made up 90% of the maltooligosaccharides produced (from maltose to maltoheptaose). The culture supernatant was concentrated using a 30K molecular weight cut-off membrane and purified by DEAE-Cellulose and Sephadex G-150 column chromatographies. The purified protein showed one band on a native-PAGE and its molecular mass was estimated as 250kDa. The 250-kDa protein was composed of tetramers of a 63-kDa protein. The isoelectric point of the purified protein was pH 6.9, and the optimum temperature for the enzyme activity was 45℃. The enzyme was quickly inactivated above 55℃, and showed a maximum activity at pH 8.5 and over 90% stability between a pH of 6 to 10. The putative N-terminal amino acid sequence of AIR-5 amylase, ATINNGTLMQYFEWYVPNDG, showed a 96% sequence similarity with that of BLA, a general liquefying amylase.
Facile Purification and Characterization of Dextransucrase from Leuconostoc mesenteroides B-512FMCM
KIM, DOMAN,KIM, DO-WON 한국미생물 · 생명공학회 1999 Journal of microbiology and biotechnology Vol.9 No.2
A simple sequence of membrane concentration and DEAE-Cellulose chromatography has been optimized to give a purified dextransucrase from Leuconostoc mesenteroides B-512FMCM with the highest specific activity (248.8 IU/㎎ protein) ever reported in high yield (overall 88.7%) for dextransucrase. When there was no sucrose in the dextransucrase and the dextran reaction digest. the dextransucrase hydrolyzed glucose from dextran. The glucose was transferred to the other glucoses from dextran and formed isomaltose and isomaltodextrin. The transglycosylation efficiency of glucose from dextran was much higher with acceptors. The dextransucrase can be used for the production of various kinds (or structures) of oligosacchaides using dextran and various acceptors with almost 100% theoretical yield.