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Sensitive and Mild Fluorogenic Reagents for Biogenic Carboxylic Acids in HPLC
Ushijima, Tamano,Saito, Mikihiko,Sasamoto, Kazumi,Ohkura, Yosuke,Ueno, Keiyu 한국분석과학회 1995 분석과학 Vol.8 No.4
Five acid hydrazides as precolumn fluorescence derivatization reagents for carboxylic acids in HPLC, which have the benzofuran or benzothiazole moiety conjugated to a furan, thiophene or oxazoline ring, were synthesized and examined in view of reactivity, separability and sensitivity. Of these hydrazides, 2-(5-hydrazinocarbonyl-2-oxazolyl)-5,6-dimethoxybenzothiazole (BTOH) was most favorable. The detection limit of lauric acid as a model acid was 0.1 pmol per $10-{\mu}l$ injection volume at S/N=3, which was roughly equal to that of an analogous compound, 2-(5-hydrazinocarbonyl-2-furyl)-5,6-dimethoxybenzothiazole. The reagent allowed rapid assays of carboxylic acids ($C_{12:0}-C_{20:4}$) within 20 min with satisfactory scparability. The method was applied to the determination of fatty acids in human sera from healthy volunteers as well as from patients with diabetes or thyroid dysfunction.
Saccharomyces cerevisiae에서 Aspergillus oryzae 유래의 exo-β-1,3- glucanase (laminarinase)의 생산 최적화
김민정(Min-Jung Kim),남수완(Soo-Wan Nam),Koichi Tamano,Masayuki Machida,김성구(Sung-Koo Kim),김연희(Yeon-Hee Kim) 한국생물공학회 2011 KSBB Journal Vol.26 No.5
In this study, a EXGA gene code for exo-β-1,3-glucanase from Aspergillus oryzae was overexpressed and secretory produced in Saccharomyces cerevisiae. To overexpress the β-1,3-glucanase, pGInu-exgA and pAInu-exgA plasmids having GAL10 and ADH1 promoter, respectively, and exoinulinase signal sequence (Inu s.s) were constructed and introduced in S. cerevisiae SEY2102 and 2805. The recombinant β-1,3- glucanase was successfully expressed and secreted into the medium and the β-1,3-glucanase activity in 2102/pGInu-exgA and 2102/pAInu-exgA strain were 5.01 unit/mL and 4.09 unit/mL, respectively. In the 2805/pGInu-exgA and 2805/pAInu-exgA strain, the β-1,3-glucanase activity showed 3.23 unit/mL and 3.22 unit/mL, respectively. Secretory efficiency in each strain reached 95% to 98%. Subsequently, the recombinant β-1,3-glucanase was used for ethanol production. Ethanol productivity in 2102/pAInu-exgA strain was 0.83 g/L when pre-treated Laminaria japonica which has initial reducing sugar of 1.4 g/L was used as substrate. It is assumed that the polysaccharides of Laminaria japonica was effectively saccharified by recombinant β-1,3-glucanase, resulting in increase of ethanol productivity. These results suggested that recombinant β-1,3- glucanase was efficiently overexpressed and secreted in S. cerevisiae SEY2102 as host strain by using ADH1 promoter-Inu s.s system.
Decreased Brain Zinc Availability Reduces Hippocampal Neurogenesis in Mice and Rats
Suh, Sang Won,Won, Seok Joon,Hamby, Aaron M,Yoo, Byung Hoon,Fan, Yang,Sheline, Christian T,Tamano, Haruna,Takeda, Atsushi,Liu, Jialing SAGE Publications 2009 Journal of cerebral blood flow and metabolism Vol.29 No.9
<P> In the adult brain, neurogenesis occurs in the subgranular zone of the dentate gyrus (DG), where high levels of vesicular zinc are localized in the presynaptic terminals. To determine whether zinc has a role in modulating hippocampal neurogenesis under normal or pathologic conditions, we manipulated the level of vesicular zinc experimentally. To reduce hippocampal vesicular zinc, rats were either fed a zinc-deficient diet or treated with a zinc chelator, clioquinol (CQ). The number of progenitor cells and immature neurons was decreased significantly in the DG after 6 weeks of dietary zinc deprivation. Conversely, the number of progenitor cells and immature neurons was restored after a 2-week reversal to a normal zinc-containing diet. Similarly, a 1-week treatment with the zinc chelator, CQ, reduced the number of progenitor cells. The results of our previous study showed that hypoglycemia increased hippocampal neurogenesis. This study shows that zinc chelation reduced hypoglycemia-induced progenitor cell proliferation and neurogenesis. Finally, the role of vesicular zinc on neurogenesis was further assessed in zinc transporter 3 (ZnT3) gene deleted mice. Zinc transporter 3 knockout (KO) mice had significantly fewer proliferating progenitor cells and immature neurons after hypoglycemia. Our data provide converging evidence in support of the essential role zinc has in modulating hippocampal neurogenesis. </P>