Browsing by Author "Kaino, Tomohiro"

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Label-free Chemical Imaging of Fungal Spore Walls by Raman Microscopy and Multivariate Curve Resolution Analysis
(2016-06-09)
Noothalapati, Hemanth
;
Sasaki, Takahiro
;
Kaino, Tomohiro
;
Kawamukai, Makoto
;
Ando, Masahiro
Fungal cell walls are medically important since they represent a drug target site for antifungal medication. So far there is no method to directly visualize structurally similar cell wall components such as alpha-glucan, beta-glucan and mannan with high specificity, especially in a label-free manner. In this study, we have developed a Raman spectroscopy based molecular imaging method and combined multivariate curve resolution analysis to enable detection and visualization of multiple polysaccharide components simultaneously at the single cell level. Our results show that vegetative cell and ascus walls are made up of both alpha- and beta-glucans while spore wall is exclusively made of alpha-glucan. Co-localization studies reveal the absence of mannans in ascus wall but are distributed primarily in spores. Such detailed picture is believed to further enhance our understanding of the dynamic spore wall architecture, eventually leading to advancements in drug discovery and development in the near future.
Studying anti-oxidative properties of inclusion complexes of alpha-lipoic acid with gamma-cyclodextrin in single living fission yeast by confocal Raman microspectroscopy
(2018-05-15)
Noothalapati, Hemanth
;
Ikarashi, Ryo
;
Iwasaki, Keita
;
Nishida, Tatsuro
;
Kaino, Tomohiro
alpha-lipoic acid (ALA) is an essential cofactor for many enzyme complexes in aerobic metabolism, especially in mitochondria of eukaryotic cells where respiration takes place. It also has excellent anti-oxidative properties. The acid has two stereo-isomers, R- and S-lipoic acid (R-LA and S-LA), but only the R-LA has biological significance and is exclusively produced in our body. A mutant strain of fission yeast, Delta dpsl, cannot synthesize coenzyme Q10, which is essential during yeast respiration, leading to oxidative stress. Therefore, it shows growth delay in the minimal medium. We studied anti-oxidant properties of ALA in its free form and their inclusion complexes with gamma-cyclodextrin using this mutant yeast model. Both free forms R- and S-LA as well as 1:1 inclusion complexes with gamma-cyclodexhin recovered growth of Delta dps1 depending on the concentration and form. However, it has no effect on the growth of wild type fission yeast strain at all. Raman microspectroscopy was employed to understand the anti-oxidant property at the molecular level. A sensitive Raman band at 1602 cm(-1) was monitored with and without addition of ALAs. It was found that 0.5 mM and 1.0 mM concentrations of ALAs had similar effect in both free and inclusion forms. At 2.5 mM ALAs, free forms inhibited the growth while inclusion complexes helped in recovered. 5.0 mM ALA showed inhibitory effect irrespective of form. Our results suggest that the Raman band at 1602 cm(-1) is a good measure of oxidative stress in fission yeast. (C) 2018 Elsevier B.V. All rights reserved.
The effect of coenzyme Q10 included by gamma-cyclodextrin on the growth of fission yeast studied by microscope Raman spectroscopy
(2013-09-24)
Nishida, Tatsuro
;
Kaino, Tomohiro
;
Ikarashi, Ryo
;
Nakata, Daisuke
;
Terao, Keiji
The inclusion complex of coenzyme Q10 (CoQ10) by gamma-cyclodextrin (gamma-CD), CoQ10-CD complex, was recently developed. The addition of the CoQ10-CD complex recovered the growth of a fission yeast mutant strain, Delta dps1, which otherwise cannot grow well due to the lack of coenzyme Q producing ability. However, the oxygen consumption rate of this strain was not restored by the addition of the CoQ10-CD complex. The addition of two other anti-oxidative reagents, glutathione and ascorbic acid, also recovered the growth of the Delta dps1 strain as well. These results indicated that the recovery of the growth of Delta dps1 was brought about by the anti-oxidative property of CoQ10. The intensity of Raman spectra of Delta dps1 at 1602 cm(-1), which is prominently observed for the wild type of the fission yeast, was compared between before and after addition of the CoQ10-CD complex. The signal was very weakly observed for Delta dps1 and did not increase in intensity by the addition of the CoQ10-CD complex. These results suggested the recovery of the growth of Delta dps1 was brought about not by the restoration of respiration function of Delta dps1 but by the anti-oxidative property of CoQ10 to result in the decrease in the oxidative stress. (c) 2013 Elsevier B.V. All rights reserved.