Browsing by Author "Torii, Hajime"

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On the origin of the 1602 cm-1 Raman band of yeasts; contribution of ergosterol
(2012-10-01)
Chiu, Liang-da
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Hullin-Matsuda, Francoise
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Kobayashi, Toshihide
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Torii, Hajime
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Hamaguchi, Hiro-o
The 1602 cm1 Raman signature, which we call the Raman spectroscopic signature of life in yeasts, is a marker Raman band for cell metabolic activity. Despite the established fact that its intensity sensitively reflects the metabolic status of the cell, its molecular origin remained unclear. In this work, we propose ergosterol as the major contributor of the 1602 cm1 Raman signature. The theoretical isotope shift calculation for ergosterol agreed with previous observations. Furthermore, experiments showed that the Raman spectrum of ergosterol corresponds very well with the depleting spectral component in yeast that behaves together with the 1602 cm1 signature when the cells are under stress. This work implies that the 1602 cm1 Raman signature could serve as an intrinsic ergosterol marker in yeasts for the study of sterol metabolism in vivo and in a label-free manner, which could not be done by any other techniques at the current stage. ((c) 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Raman Spectra of Isotope-substituted Mitochondria of Living Budding Yeast Cells: Possible Origin of the "Raman Spectroscopic Signature of Life"
(2009-09-05)
Onogi, Chikao
;
Torii, Hajime
;
Hamaguchi, Hiro-o
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應用化學系
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應用化學系分子科學碩博班
The (13)C and (2)H isotope Substitution effects have been examined for the "Raman spectroscopic signature of life," a mitochondrial Raman band at 1602 cm(-1) that sharply reflects the metabolic activity of living yeast cells. The band shifts to 1542 cm(-1) with (13)C substitution and to 1599 cm(-1) with (2)H substitution. Normal mode analysis based oil a DFT calculation suggests that it originates from a C=C double bond having no hydrogen atoms attached to the carbon atoms. The in-phase C=C stretch mode of ubisemiquinone radicals (CoQ and/or CoQH*) emerges as a strong candidate for the origin of the 1602 cm(-1) band.