Proceedings of the Japan Academy, Series B
Online ISSN : 1349-2896
Print ISSN : 0386-2208
ISSN-L : 0386-2208
Volume 78 , Issue 8
Showing 1-4 articles out of 4 articles from the selected issue
  • Hiroshi TOMODA, Ichiji NAMATAME, Satoshi OMURA
    2002 Volume 78 Issue 8 Pages 217-240
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Microbial products inhibiting lipid metabolism, particularly involved in the fatty acid and cholesterol metabolic pathways were screened with various assay systems. Inhibitors were discovered for fatty acid synthase, acyl-coenzyme A (CoA) synthetase and diacylglycerol acyltransferase in fatty acid metabolism and 3-hydroxy-3-methylglutaryl-CoA synthase, acyl-CoA:cholesterol acyltransferase and cholesteryl ester transfer protein in cholesterol metabolism.
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  • Akira ISOGAI, Kokichi HINATA
    2002 Volume 78 Issue 8 Pages 241-249
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    Many higher plants have developed systems to prevent self-fertilization. The self-incompatibility (SI) system has been well known since the time of Darwin. In Brassica, SI is controlled by a single polymorphic locus called S. Discrimination of self and non-self pollen by the pistil should occur on the surface of the stigma. We have investigated the molecular mechanism underlying the SI system and have determined the S-gene products in pistil and pollen. The S-determinant of pollen (SP11) is a small cysteine-rich protein and is the ligand of a receptor complex in papilla cells, which is composed of S-receptor kinase (SRK) and S-locus glycoprotein (SLG). Ligand binding induces the autophosphorylation of SRK, which triggers the signaling cascade that results in the rejection of self-pollen. The ligand-receptor interaction occurs in an S-haplotype specific manner. This is the fundamental reaction of self-recognition system underlying SI in Brassica.
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  • Akira MURAKAMI
    2002 Volume 78 Issue 8 Pages 250-255
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    This paper presents an approach for identifying the parameters in elasto-plastic constitutive model for soil while controling the boundary conditions, e.g., the history of loading, and points out the role of the time update scheme of Kalman filtering in an inverse analysis. For elasto-plastic material, the deformation of the body depends on the loading history, the parameters of the constitutive model, and the initial stresses, whereas only the current stress state determines the deformation of elastic material. It is shown here that a saturated soil deposit provides various settlement curves under different patterns of external action, such as embankment loading and excavation, via finite element computation using an elasto-plastic model. Without precise knowledge of the loading history, however, it is difficult to identify some parameters of the elasto-pl astic material.The formulation of an inverse problem, using the Kalman filter, is examined to overcome this difficulty, while incorporating the transient loading history into the deterministic control input of the state equation.
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  • Hideo CHIBA, Emiko IWATA
    2002 Volume 78 Issue 8 Pages 256-262
    Published: 2002
    Released: October 17, 2006
    JOURNALS FREE ACCESS
    It has been shown directly by means of the HPLC system that reactive lipid hydroperoxides containing the corresponding radicals, which are produced by autoxidative chain reactions from polyunsaturated fatty acids under atmospheric conditions, can decompose proteins into their fragments or fission products according to fragility originated in their structural characteristics. Similarly, it has been verified that several enzymes are inactivated to different extents by the strong actions of active lipid hydroperoxides. It has also been clarified that the activity of an enzyme (lactate dehydrogenase) is completely destroyed just by a water-soluble radical (vitamin C radical or ovalbumin protein radical), which is prepared by radical migration between lipid radicals and radical scavengers such as vitamin C and ovalbumin by means of constrained direct contact of both compounds.
    Therefore, it is strongly suggested that lipid hydroperoxides containing radicals may play a significant role with regard to protein metabolism in destroying the structures of proteins and the activities of enzymes.
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