VITAMINS
Online ISSN : 2424-080X
Print ISSN : 0006-386X
Volume 79, Issue 2
Displaying 1-15 of 15 articles from this issue
  • [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 69-
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
  • Haruo MISONO, Makoto ASHIUCHI
    Article type: Article
    2005 Volume 79 Issue 2 Pages 71-78
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Poly-γ-glutamate (PGA) is an unusual polypeptide in which glutamate is polymerized via γ-amide linkages. PGA is produced by Bacillus strains, Natrialba aegyptiaca, and hydra. PGA, which is biodegradable and highly water-absorbent acidic polymer, is not attacked by proteases, evades mammalian immune defense mechanisms, binds Ca^<2+>, and serves as a cryoprotective material. PGA may physiologically function as an adaptation agent in various environments. Multifarious applications of PGA have been developed based on its function. PGA produced by Bacillus subtilis IFO 3336 contains a large amount of D-glutamate. D-Glutamate was formed from L-glutamate by glutamate racemase in this organism. Two kinds of glutamate racemase isozymes, Glr and YrpC, were found in B, subtilis IFO 3336, and Glr supplied D-glutamate for the PGA production. The pgsBCA genes encoding the membrane-associated PGA synthetase complex of B. subtilis IFO 3336 were isolated. The PgsBCA enzyme complex synthesized PGA in an amidoligation-like manner. The structure and function of the enzyme complex are also discussed.
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  • Hiroki ABE, Naoko YOSHIKAWA, Golam SAROWER, Shigeru OKADA
    Article type: Article
    2005 Volume 79 Issue 2 Pages 79-86
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Aquatic crustaceans and some bivalve mollusks contain a copious amount of free D-alanine (3-100 umol/g wet wt.) in their tissues. Under high osmotic stress, D-and L-alanine were largely accumulated In these animals and were proven to be one of the major compatible osmolytes responsible for the intracellular isoosmotic regulation. cDNAs of alanlne racemase catalyzing the interconversion of D-and L-alanine were cloned from the muscle and hepatopancreas of kuruma prawn. Carp which feeds on invertebrates contained only a trace amount of D-alanine and showed high activities of D-amino acid and D-aspartate oxidases in some tissues. A cDNA of D-amino acid oxidase was cloned from the hepatopancreas of carp. During adminlstration of D-alanine to carp, mRNA and enzyme activity of D-amino acid oxidase were largely increased in intestine followed by hepatopancreas and kidney, suggesting the inducible nature of the enzyme.
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  • Takahiro SUZUKI, Hiroshi ICHlNOSE
    Article type: Article
    2005 Volume 79 Issue 2 Pages 87-95
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Tetrahydrobipterin (BH4) is an essential cofactor for three aromatic amino acid monooxygenases phenylalanine, tyrosine, and tryptophane hydroxylases (PAH, TH, and TPH)-and for nitric oxide synthase (NOS). BH4 plays crucial roles in phenylalanine metabolism, neurotransmitter synthesis, vasodilation, and immune response. In mammals, BH4 synthesis is regulated by various hormones and cytokines, and other stimuli. BH4 deficiency is responsible for malignant type of hyperphenylalaninemla and dopa-responsive dystonia, and is recently supposed to be involved in endothelial dysfunction and neurodegeneration. Recent works have shown that administration of BH4 is effective for patients with hyperphenylalanlnemia who have a genetic defect in the PAH gene, although their BH4 levels are normal. More notables are the beneficial effects of BH4 supplementation on endothelial dysfunction caused by hypercholesterolemia, diabetes, hypertension, and chronic smoking. In this review, we summarize recent progress in the BH4 research.
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  • Hiroshi SONE, Mitsuharu YUUDA, Nobuyo HIGASHI, Haruki SENOO
    Article type: Article
    2005 Volume 79 Issue 2 Pages 97-112
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Hiroshl Sone, the first author of this article, entered the Riken Vitamin Company and started his research on natural vitamin A in the Shiogama factory in Miyagi Prefecture, Japan, in 1947. His first research project was a search for new sources of natural vitamin A. He analyzed more than 2000 specimens, namely, the liver and other organs from various kinds of fish that had not been utilized for vitamin A sources then, and finally found that the pyloric caecum (appendix pylorus) and the Intestinal wall of arrow-toothed halibut (Atheresthes evermanni Jordan et Starks) contained very high concentrations of vitamin A. However, the basic and logical cause of such a high density of vitamin A in the extrahepatic organs In this fish remained enigmatic for Sone for over 50 years. Recently, the answer was given by Dr.H.Senoo who investigated uptake and storage of vitamin A in animals and found that vitamin A spilled out from the liver into extrahepatic organs in arctic animals. After Sone discovered this new source of vitamin A, he and his colleagues firstly challenged the development of a new method to obtain highly -concentrated vitamin A from liver oil.
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  • [in Japanese], [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 113-115
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
  • [in Japanese], [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 116-117
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
  • [in Japanese], [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 118-119
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
  • [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 121-
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
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  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    Article type: Article
    2005 Volume 79 Issue 2 Pages 121-122
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Download PDF (291K)
  • [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 122-
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Download PDF (175K)
  • [in Japanese], [in Japanese], [in Japanese], [in Japanese], [in Japane ...
    Article type: Article
    2005 Volume 79 Issue 2 Pages 122-123
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Download PDF (300K)
  • [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 123-124
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Download PDF (288K)
  • [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 124-
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Download PDF (164K)
  • [in Japanese]
    Article type: Article
    2005 Volume 79 Issue 2 Pages 124-
    Published: February 25, 2005
    Released on J-STAGE: October 10, 2017
    JOURNAL FREE ACCESS
    Download PDF (164K)
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