VITAMINS
Online ISSN : 2424-080X
Print ISSN : 0006-386X
Volume 70, Issue 11
Displaying 1-6 of 6 articles from this issue
  • Mayumi SHIMIZU, Toshio MITSUNAGA
    Article type: Article
    1996 Volume 70 Issue 11 Pages 501-510
    Published: November 25, 1996
    Released on J-STAGE: December 26, 2017
    JOURNAL FREE ACCESS
    Thiamin-binding proteins (TBPs) were widely distributed in plants as well as in microorganisms and animals. In plants, the proteins mainly existed in seeds and were concentrated in the germ. The TBPs isolated from rice, buckwheat, and sesame seeds consisted of much glutamic acid (or glutamin) and bound to thiamin specifically. Sesame seed has three kinds of the TBP whose molecular mass and the optimum pH for thiamin binding are different from the TBPs from rice and buckwheat seeds. The TBPs from these three seeds did not show immunological similarity each other, whereas the TBPs similar to that from rice seed were distributed in gramineous seeds, indicating that the origin of the TBPs might differ. The TBP accumulated during seed development with thiamin and degraded at the early stage of germination accompanying the release of thiamin. These results suggest that TBPs in plant have dual functions as thiamin retainer and storage protein. Thiamin seems to be stored by binding to the protein in dormant seeds, and to be released with the protein degradation and used as a coenzyme when seeds germinate, while TBPs may provide nitrogen at germination.
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  • Satoshi WATANABE, Tetsuya FUKUI
    Article type: Article
    1996 Volume 70 Issue 11 Pages 511-518
    Published: November 25, 1996
    Released on J-STAGE: December 26, 2017
    JOURNAL FREE ACCESS
    Potassium bromate (KBrO_3), a food additive, induces lipid peroxidation in the presence of reduced glutathione (GSH). Oxygen uptake and conjugated diene in the linoleic acid micelle solution relatively increased by the addition of KBrO_3 and GSH. These increases were inhibited with a singlet oxygen quencher, sodium azide or β-carotene, respectively, and similarly inhibited with retinyl acetate. But the decrease of retinyl acetate by KBrO_3 and GSH was not inhibited with sodium azide or β-carotene. These results suggest that retinyl acetate inhibited the peroxidation of linoleic acid with KBrO_3 and GSH by the scavenging of glutathione thiyl radical produced from GSH.
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  • Keiko TAZUYA, Kazuko YAMADA, Hiroshi KUMAOKA
    Article type: Article
    1996 Volume 70 Issue 11 Pages 519-524
    Published: November 25, 1996
    Released on J-STAGE: December 26, 2017
    JOURNAL FREE ACCESS
    Formate is incorporated into the C-2 of the pyrimidine moiety of thiamin in Escherichia coli under aerobic conditions. However, the incorporation of formate into the pyrimidine was decreased under anaerobic conditions. Although the incorporation of [^<13>C] formate into pyrimidine was decreased under static and anaerobic conditions, the incorporation was not inhibited by pantothenate or aspartate. These results suggest that another biosynthetic route for the pyrimidine is induced under anaerobic conditions in E. coli. On the other hand, the nitrogen atom of L-[^<15>N]tyrosine was incorporated into the thiazole moiety of thiamin under aerobic and anaerobic conditions. The biosynthetic route of the thiazole moiety was not changed by O_2 concentration.
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  • Article type: Appendix
    1996 Volume 70 Issue 11 Pages 525-529
    Published: November 25, 1996
    Released on J-STAGE: December 26, 2017
    JOURNAL FREE ACCESS
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  • [in Japanese]
    Article type: Article
    1996 Volume 70 Issue 11 Pages 531-533
    Published: November 25, 1996
    Released on J-STAGE: December 26, 2017
    JOURNAL FREE ACCESS
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  • [in Japanese]
    Article type: Article
    1996 Volume 70 Issue 11 Pages 533-
    Published: November 25, 1996
    Released on J-STAGE: December 26, 2017
    JOURNAL FREE ACCESS
    Download PDF (148K)
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