LIVIVO - Search results -

Search results

Result 1 - 10 of total 33

Search options

Article ; Online: Label-free autofluorescence lifetime reveals the structural dynamics of ataxin-3 inside droplets formed via liquid-liquid phase separation.

Matsuura, Uchu / Tahara, Shinya / Kajimoto, Shinji / Nakabayashi, Takakazu

2023 Volume 13, Issue 1, Page(s) 6389

Abstract: Liquid-liquid phase separation is a phenomenon that features the formation of liquid droplets containing concentrated solutes. The droplets of neurodegeneration-associated proteins are prone to generate aggregates and cause diseases. To uncover the ... ...

Abstract	Liquid-liquid phase separation is a phenomenon that features the formation of liquid droplets containing concentrated solutes. The droplets of neurodegeneration-associated proteins are prone to generate aggregates and cause diseases. To uncover the aggregation process from the droplets, it is necessary to analyze the protein structure with keeping the droplet state in a label-free manner, but there was no suitable method. In this study, we observed the structural changes of ataxin-3, a protein associated with Machado-Joseph disease, inside the droplets, using autofluorescence lifetime microscopy. Each droplet showed autofluorescence due to tryptophan (Trp) residues, and its lifetime increased with time, reflecting structural changes toward aggregation. We used Trp mutants to reveal the structural changes around each Trp and showed that the structural change consists of several steps on different timescales. We demonstrated that the present method visualizes the protein dynamics inside a droplet in a label-free manner. Further investigations revealed that the aggregate structure formed in the droplets differs from that formed in dispersed solutions and that a polyglutamine repeat extension in ataxin-3 hardly modulates the aggregation dynamics in the droplets. These findings highlight that the droplet environment facilitates unique protein dynamics different from those in solutions.
MeSH term(s)	Humans ; Ataxin-3/metabolism ; Machado-Joseph Disease/metabolism
Chemical Substances	Ataxin-3 (EC 3.4.19.12)
Language	English
Publishing date	2023-04-19
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	2615211-3
ISSN	2045-2322 ; 2045-2322
ISSN (online)	2045-2322
ISSN	2045-2322
DOI	10.1038/s41598-023-33268-y
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

This service is chargeable due to the Delivery terms set by subito. Orders including an article and supplementary material will be classified as separate orders. In these cases, fees will be demanded for each order.

Article ; Online: Establishment of a Method for the Introduction of Poorly Water-Soluble Drugs in Cells and Evaluation of Intracellular Concentration Distribution Using Resonance Raman Imaging.

Koga, Keisuke / Kajimoto, Shinji / Yoshizaki, Yuta / Takahashi, Hiroaki / Kageyama, Lisa / Konno, Tomohiro / Nakabayashi, Takakazu

The journal of physical chemistry. B

2024 Volume 128, Issue 6, Page(s) 1350–1359

Abstract: Label-free measurement is essential to understand the metabolism of drug molecules introduced into cells. Raman imaging is a powerful method to investigate intracellular drug molecules because it provides in situ label-free observation of introduced ... ...

Abstract	Label-free measurement is essential to understand the metabolism of drug molecules introduced into cells. Raman imaging is a powerful method to investigate intracellular drug molecules because it provides in situ label-free observation of introduced molecules. In this study, we propose that Raman imaging can be used not only to observe the intracellular distribution of drug molecules but also to quantitatively visualize the concentration distribution reflecting each organelle in a single living cell using the Raman band of extracellular water as an intensity standard. We dissolved poorly water-soluble all-
MeSH term(s)	Water ; beta Carotene ; Biological Transport
Chemical Substances	Water (059QF0KO0R) ; beta Carotene (01YAE03M7J)
Language	English
Publishing date	2024-01-31
Publishing country	United States
Document type	Journal Article
ISSN	1520-5207
ISSN (online)	1520-5207
DOI	10.1021/acs.jpcb.3c06601
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Label-Free Tracking of Nanoprodrug Cellular Uptake and Metabolism Using Raman and Autofluorescence Imaging.

Machida, Masato / Sugimura, Toshiki / Kajimoto, Shinji / Taemaitree, Farsai / Koseki, Yoshitaka / Kasai, Hitoshi / Nakabayashi, Takakazu

The journal of physical chemistry. B

2023 Volume 127, Issue 17, Page(s) 3851–3860

Abstract: Nano-DDS, a drug delivery system using nanoparticles, is a promising tool to reduce adverse drug reactions and maximize drug efficiency. Understanding the intracellular dynamics following the accumulation of nanoparticles in tissues, such as cellular ... ...

Abstract	Nano-DDS, a drug delivery system using nanoparticles, is a promising tool to reduce adverse drug reactions and maximize drug efficiency. Understanding the intracellular dynamics following the accumulation of nanoparticles in tissues, such as cellular uptake, distribution, metabolism, and pharmacological effects, is essential to maximize drug efficiency; however, it remains elusive. In this study, we tracked the intracellular behavior of nanoparticles of a prodrug, cholesterol-linked SN-38 (CLS), in a label-free manner using Raman and autofluorescence imaging. Bright autofluorescent spots were observed in cells treated with CLS nanoparticles, and the color tone of the bright spots changed with incubation time. The Raman spectra of the bright spots showed that the autofluorescence came from the nanoparticles taken into cells, and the change in color of bright spots indicated that CLS turned into SN-38 via hydrolysis inside a cell. It was found that most of the SN-38 were localized in small regions in the cytoplasm even after the conversion from CLS, and only a small amount of SN-38 was dissolved and migrated into other cytoplasm regions and the nucleus. The massive size growth of cells was observed within several tens of hours after the treatment with CLS nanoparticles. Moreover, Raman images of cells using the cytochrome
MeSH term(s)	Prodrugs/pharmacology ; Irinotecan ; Drug Delivery Systems/methods ; Nanoparticles ; Optical Imaging ; Spectrum Analysis, Raman/methods
Chemical Substances	Prodrugs ; Irinotecan (7673326042)
Language	English
Publishing date	2023-04-24
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ISSN	1520-5207
ISSN (online)	1520-5207
DOI	10.1021/acs.jpcb.3c01133
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Observation of the changes in the chemical composition of lipid droplets using Raman microscopy.

Takahashi, Hiroaki / Yanamisawa, Aya / Kajimoto, Shinji / Nakabayashi, Takakazu

Physical chemistry chemical physics : PCCP

2020 Volume 22, Issue 38, Page(s) 21646–21650

Abstract: We report the dynamics of lipid droplet formation induced by introducing cis- and/or trans-fatty acids into cells. Raman imaging allows the chemical analysis of each droplet, showing that exogenous fatty acids initially enter original endogenous droplets, ...

Abstract	We report the dynamics of lipid droplet formation induced by introducing cis- and/or trans-fatty acids into cells. Raman imaging allows the chemical analysis of each droplet, showing that exogenous fatty acids initially enter original endogenous droplets, then induce additional droplets containing endogenous lipids, and finally form their droplets.
MeSH term(s)	Fatty Acids/analysis ; HeLa Cells ; Humans ; Lipid Droplets/chemistry ; Microscopy ; Spectrum Analysis, Raman
Chemical Substances	Fatty Acids
Language	English
Publishing date	2020-09-28
Publishing country	England
Document type	Journal Article
ZDB-ID	1476244-4
ISSN	1463-9084 ; 1463-9076
ISSN (online)	1463-9084
ISSN	1463-9076
DOI	10.1039/d0cp03805a
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Article ; Online: Label-Free Imaging of Intracellular Temperature by Using the O-H Stretching Raman Band of Water.

Sugimura, Toshiki / Kajimoto, Shinji / Nakabayashi, Takakazu

Angewandte Chemie (International ed. in English)

2020 Volume 59, Issue 20, Page(s) 7755–7760

Abstract: We propose a label-free method for measuring intracellular temperature using a Raman image of a cell in the O-H stretching band. Raman spectra of cultured cells and the medium were first measured at various temperatures using a Raman microscope and the ... ...

Abstract	We propose a label-free method for measuring intracellular temperature using a Raman image of a cell in the O-H stretching band. Raman spectra of cultured cells and the medium were first measured at various temperatures using a Raman microscope and the intensity ratio of the two regions of the O-H stretching band was calculated. The intensity ratio varies linearly with temperature in both the medium and cells, and the resulting calibration lines allow simultaneous visualization of both intracellular and extracellular temperatures in a label-free manner. We applied this method to the measurement of temperature changes after the introduction of FCCP (carbonyl cyanide-p-trifluoromethoxyphenylhydrazone) in living cells. We observed a temperature rise in the cytoplasm and succeeded in obtaining an image of the change in intracellular temperature after the FCCP treatment.
MeSH term(s)	Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone/chemistry ; Extracellular Space/chemistry ; HeLa Cells ; Humans ; Hydrogen/chemistry ; Intracellular Space/chemistry ; Molecular Imaging ; Oxygen/chemistry ; Spectrum Analysis, Raman ; Temperature ; Water/chemistry
Chemical Substances	Water (059QF0KO0R) ; Carbonyl Cyanide p-Trifluoromethoxyphenylhydrazone (370-86-5) ; Hydrogen (7YNJ3PO35Z) ; Oxygen (S88TT14065)
Language	English
Publishing date	2020-03-06
Publishing country	Germany
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	2011836-3
ISSN	1521-3773 ; 1433-7851
ISSN (online)	1521-3773
ISSN	1433-7851
DOI	10.1002/anie.201915846
Database	MEDical Literature Analysis and Retrieval System OnLINE

Full text online

Accessible to users with ZB MED library card

Order via subito

Details ▾
- Full text online
- Order with fees

Article ; Online: Regulation of Cell Volume by Nanosecond Pulsed Electric Fields.

Yang, Qi / Kajimoto, Shinji / Kobayashi, Yuki / Hiramatsu, Hirotsugu / Nakabayashi, Takakazu

The journal of physical chemistry. B

2021 Volume 125, Issue 38, Page(s) 10692–10700

Abstract: Stimulation of cells by nanosecond pulsed electric fields (nsPEFs) has attracted attention as a technology for medical applications such as cancer treatment. nsPEFs have been shown to affect intracellular environments without significant damage to cell ... ...

Abstract	Stimulation of cells by nanosecond pulsed electric fields (nsPEFs) has attracted attention as a technology for medical applications such as cancer treatment. nsPEFs have been shown to affect intracellular environments without significant damage to cell membranes; however, the mechanism underlying the effect of nsPEFs on cells remains unclear. In this study, we constructed electrodes for applying nsPEFs and analyzed the change in volume of a single cell due to nsPEFs using fluorescence and Raman microscopy. It was shown that the direction of the change depended on the applied electric field; expansion due to the influx of water was observed at high electric field, and cell shrinkage was observed at low electric field. The change in cell volume was correlated to the change in the intracellular Ca
MeSH term(s)	Cell Size ; Electricity
Language	English
Publishing date	2021-09-14
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ISSN	1520-5207
ISSN (online)	1520-5207
DOI	10.1021/acs.jpcb.1c06058
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article ; Online: Concentration Quantification of the Low-Complexity Domain of Fused in Sarcoma inside a Single Droplet and Effects of Solution Parameters.

Yokosawa, Kohei / Kajimoto, Shinji / Shibata, Daiki / Kuroi, Kunisato / Konno, Tomohiro / Nakabayashi, Takakazu

The journal of physical chemistry letters

2022 Volume 13, Issue 24, Page(s) 5692–5697

Abstract: Liquid-liquid phase separation (LLPS) is an important phenomenon in biology, and it is desirable to develop quantitative methods to analyze protein droplets generated by LLPS. This study quantified the change in protein concentration in a droplet in ... ...

Abstract	Liquid-liquid phase separation (LLPS) is an important phenomenon in biology, and it is desirable to develop quantitative methods to analyze protein droplets generated by LLPS. This study quantified the change in protein concentration in a droplet in label-free and single-droplet conditions using Raman imaging and the Raman band of water as an intensity standard. Small changes in the protein concentration with variations in pH and salt concentration were observed, and it was shown that the concentration in the droplet decreases as the conditions become less favorable for droplet formation. The effect of exposure to 1,6-hexanediol was also examined, and this additive was found to decrease the protein concentration in the droplet. A model can be proposed in which the addition of 1,6-hexanediol reduces the protein concentration in the droplet, and the droplet disappears when the concentration falls below a certain threshold value.
MeSH term(s)	Humans ; Proteins ; Sarcoma ; Sodium Chloride ; Water/chemistry
Chemical Substances	Proteins ; Water (059QF0KO0R) ; Sodium Chloride (451W47IQ8X)
Language	English
Publishing date	2022-06-16
Publishing country	United States
Document type	Journal Article
ISSN	1948-7185
ISSN (online)	1948-7185
DOI	10.1021/acs.jpclett.2c00962
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article: Regulation of Cell Volume by Nanosecond Pulsed Electric Fields

Yang, Qi / Kajimoto, Shinji / Kobayashi, Yuki / Hiramatsu, Hirotsugu / Nakabayashi, Takakazu

Journal of physical chemistry. 2021 Sept. 14, v. 125, no. 38

2021

Abstract	Stimulation of cells by nanosecond pulsed electric fields (nsPEFs) has attracted attention as a technology for medical applications such as cancer treatment. nsPEFs have been shown to affect intracellular environments without significant damage to cell membranes; however, the mechanism underlying the effect of nsPEFs on cells remains unclear. In this study, we constructed electrodes for applying nsPEFs and analyzed the change in volume of a single cell due to nsPEFs using fluorescence and Raman microscopy. It was shown that the direction of the change depended on the applied electric field; expansion due to the influx of water was observed at high electric field, and cell shrinkage was observed at low electric field. The change in cell volume was correlated to the change in the intracellular Ca²⁺ concentration, and nsPEFs-induced shrinking was not observed when the Ca²⁺-free medium was used. This result suggests that the cell shrinkage is related to the regulatory volume decrease where the cell adjusts the increase in intracellular Ca²⁺ concentration, inducing the efflux of ions and water from the cell.
Keywords	calcium ; cancer therapy ; electric field ; fluorescence ; physical chemistry ; shrinkage
Language	English
Dates of publication	2021-0914
Size	p. 10692-10700.
Publishing place	American Chemical Society
Document type	Article
ISSN	1520-5207
DOI	10.1021/acs.jpcb.1c06058
Database	NAL-Catalogue (AGRICOLA)

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

Article: Observation of liquid-liquid phase separation of ataxin-3 and quantitative evaluation of its concentration in a single droplet using Raman microscopy.

Murakami, Kazuki / Kajimoto, Shinji / Shibata, Daiki / Kuroi, Kunisato / Fujii, Fumihiko / Nakabayashi, Takakazu

Chemical science

2021 Volume 12, Issue 21, Page(s) 7411–7418

Abstract: Liquid-liquid phase separation (LLPS) plays an important role in a variety of biological processes and is also associated with protein aggregation in neurodegenerative diseases. Quantification of LLPS is necessary to elucidate the mechanism of LLPS and ... ...

Abstract	Liquid-liquid phase separation (LLPS) plays an important role in a variety of biological processes and is also associated with protein aggregation in neurodegenerative diseases. Quantification of LLPS is necessary to elucidate the mechanism of LLPS and the subsequent aggregation process. In this study, we showed that ataxin-3, which is associated with Machado-Joseph disease, exhibits LLPS in an intracellular crowding environment mimicked by biopolymers, and proposed that a single droplet formed in LLPS can be quantified using Raman microscopy in a label-free manner. We succeeded in evaluating the protein concentration and identifying the components present inside and outside a droplet using the O-H stretching band of water as an internal intensity standard. Only water and protein were detected to be present inside droplets with crowding agents remaining outside. The protein concentration in a droplet was dependent on the crowding environment, indicating that the protein concentration and intracellular environment should be considered when investigating LLPS. Raman microscopy has the potential to become a powerful technique for clarifying the chemical nature of LLPS and its relationship with protein aggregation.
Language	English
Publishing date	2021-04-14
Publishing country	England
Document type	Journal Article
ZDB-ID	2559110-1
ISSN	2041-6539 ; 2041-6520
ISSN (online)	2041-6539
ISSN	2041-6520
DOI	10.1039/d0sc06095j
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Article ; Online: Embedding a Metal-Binding Motif for Copper Transporter into a Lipid Bilayer by Cu(I) Binding.

Okada, Mariko / Kajimoto, Shinji / Nakabayashi, Takakazu

The journal of physical chemistry. B

2018 Volume 122, Issue 24, Page(s) 6364–6370

Abstract: Peptide-lipid interactions are widely involved with biologically significant phenomena, including the pathogenic mechanisms of protein misfolding diseases and transmembrane protein folding. In this paper, the interaction of the cysteine/tryptophan (Cys/ ... ...

Abstract	Peptide-lipid interactions are widely involved with biologically significant phenomena, including the pathogenic mechanisms of protein misfolding diseases and transmembrane protein folding. In this paper, the interaction of the cysteine/tryptophan (Cys/Trp) motif, which is a metal-binding motif of copper transporter (Ctr) proteins, with a lipid bilayer was studied using fluorescence and circular dichroism (CD) spectroscopy. The binding of Cu(I) to the Cys/Trp motif induced a large red-edge excitation shift in the Trp fluorescence, indicating that the Trp residue is located inside the lipid bilayer following complexation of Cu(I) with the Cys/Trp motif. The Stern-Volmer quenching of the Trp fluorescence also supported the Cu(I) binding peptide embedding in the lipid bilayer. The measurement of the CD spectra indicated the increase in β-sheet content of the Cys/Trp motif peptide as a result of Cu(I) binding. These results lead to the conclusion that complexation with Cu(I) induces the change in the secondary structure of the Cys/Trp motif, which results in the peptide embedding in the lipid bilayer. Cu(I)-induced enhancement of the lipid affinity is discussed in terms of the mechanism for copper transport by Ctr.
MeSH term(s)	Amino Acid Sequence ; Circular Dichroism ; Copper/chemistry ; Copper/metabolism ; Cysteine/chemistry ; Lipid Bilayers/chemistry ; Lipid Bilayers/metabolism ; Peptides/chemical synthesis ; Peptides/chemistry ; Peptides/metabolism ; Protein Binding ; Protein Conformation, beta-Strand ; Spectrometry, Fluorescence ; Tryptophan/chemistry
Chemical Substances	Lipid Bilayers ; Peptides ; Copper (789U1901C5) ; Tryptophan (8DUH1N11BX) ; Cysteine (K848JZ4886)
Language	English
Publishing date	2018-06-08
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ISSN	1520-5207
ISSN (online)	1520-5207
DOI	10.1021/acs.jpcb.8b03179
Database	MEDical Literature Analysis and Retrieval System OnLINE

Order via subito

Inter-library loan at ZB MED

Your chosen title can be delivered directly to ZB MED Cologne location if you are registered as a user at ZB MED Cologne.

To top

More links

Kategorien

Order via subito

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Full text online

More links

Kategorien

Order via subito

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

Inter-library loan at ZB MED

More links

Kategorien

Order via subito

More links

Kategorien

Order via subito

Inter-library loan at ZB MED