著者
上岡 龍一 市原 英明 古水 雄志
出版者
一般社団法人 日本生物物理学会
雑誌
生物物理 (ISSN:05824052)
巻号頁・発行日
vol.54, no.1, pp.005-010, 2014 (Released:2014-01-29)
参考文献数
26

We have produced hybrid liposomes (HL) which can be prepared by sonication of a mixture of vesicular and micellar molecules in a buffer solution. Some interesting results are as follows; HL remarkably inhibited the growth of cancer cells along with apoptosis in vitro and in vivo. Anticancer effects increased with a growth in membrane fluidity of HL and fluidity of plasma membranes of cancer cells. In clinical applications, prolonged survival and remarkable reduction of neoplasm were attained in patients with lymphoma after the treatment with HL without any side effects after the approval of the bioethics committee.
著者
藤崎 久雄
出版者
一般社団法人 日本生物物理学会
雑誌
生物物理 (ISSN:05824052)
巻号頁・発行日
vol.40, no.3, pp.195-198, 0001-01-01 (Released:2001-04-26)
参考文献数
10
著者
矢吹 貞人
出版者
一般社団法人 日本生物物理学会
雑誌
生物物理 (ISSN:05824052)
巻号頁・発行日
vol.21, no.5, pp.237-246, 1981-09-25 (Released:2009-05-25)
参考文献数
7
著者
Jun Tamogami Takashi Kikukawa Toshifumi Nara Makoto Demura Tomomi Kimura-Someya Mikako Shirouzu Shigeyuki Yokoyama Seiji Miyauchi Kazumi Shimono Naoki Kamo
出版者
一般社団法人 日本生物物理学会
雑誌
Biophysics and Physicobiology (ISSN:21894779)
巻号頁・発行日
vol.14, pp.49-55, 2017 (Released:2017-03-18)
参考文献数
25
被引用文献数
7

A spectrally silent change is often observed in the photocycle of microbial rhodopsins. Here, we suggest the presence of two O intermediates in the photocycle of Acetabularia rhodopsin II (ARII or also called Ace2), a light-driven algal proton pump from Acetabularia acetabulum. ARII exhibits a photocycle including a quasi-equilibrium state of M, N, and O (M<=>N<=>O→) at near neutral and above pH values. However, acidification of the medium below pH ~5.5 causes no accumulation of N, resulting in that the photocycle of ARII can be described as an irreversible scheme (M→O→). This may facilitate the investigation of the latter part of the photocycle, especially the rise and decay of O, during which molecular events have not been sufficiently understood. Thus we analyzed the photocycle under acidic conditions (pH ≤ 5.5). Analysis of the absorbance change at 610 nm, which mainly monitors the fractional concentration changes of K and O, was performed and revealed a photocycle scheme containing two sequential O-states with the different molar extinction coefficients. These photoproducts, termed O1 and O2, may be even produced at physiological pH, although they are not clearly observed under this condition due to the existence of a long M-N-O equilibrium.
著者
Yumeka Yamauchi Masae Konno Shota Ito Satoshi P. Tsunoda Keiichi Inoue Hideki Kandori
出版者
一般社団法人 日本生物物理学会
雑誌
Biophysics and Physicobiology (ISSN:21894779)
巻号頁・発行日
vol.14, pp.57-66, 2017 (Released:2017-05-20)
参考文献数
58
被引用文献数
35

Microbial rhodopsins are membrane proteins found widely in archaea, eubacteria and eukaryotes (fungal and algal species). They have various functions, such as light-driven ion pumps, light-gated ion channels, light sensors and light-activated enzymes. A light-driven proton pump bacteriorhodopsin (BR) contains a DTD motif at positions 85, 89, and 96, which is unique to archaeal proton pumps. Recently, channelrhodopsins (ChRs) containing the DTD motif, whose sequential identity is ~20% similar to BR and to cation ChRs in Chlamydomonas reinhardtii (CrCCRs), were found. While extensive studies on ChRs have been performed with CrCCR2, the molecular properties of DTD ChRs remain an intrigue. In this paper, we studied a DTD rhodopsin from G. theta (GtCCR4) using electrophysiological measurements, flash photolysis, and low-temperature difference FTIR spectroscopy. Electrophysiological measurements clearly showed that GtCCR4 functions as a light-gated cation channel, similar to other G. theta DTD ChRs (GtCCR1-3). Light-driven proton pump activity was also suggested for GtCCR4. Both electrophysiological and flash photolysis experiments showed that channel closing occurs upon reprotonation of the Schiff base, suggesting that the dynamics of retinal and channels are tightly coupled in GtCCR4. From Fourier transform infrared (FTIR) spectroscopy at 77 K, we found that the primary reaction is an all-trans to a 13-cis photoisomerization, like other microbial rhodopsins, although perturbations in the secondary structure were much smaller in GtCCR4 than in CrCCR2.

1 0 0 0 OA X線顕微鏡

著者
木原 裕 若林 克三
出版者
一般社団法人 日本生物物理学会
雑誌
生物物理 (ISSN:05824052)
巻号頁・発行日
vol.24, no.4, pp.178-182, 1984-07-25 (Released:2009-07-09)
参考文献数
13
著者
矢田 慶治 篠原 邦夫
出版者
一般社団法人 日本生物物理学会
雑誌
生物物理 (ISSN:05824052)
巻号頁・発行日
vol.33, no.4, pp.198-206, 1993-07-25 (Released:2009-07-09)
参考文献数
54
被引用文献数
1

Developments in soft x-ray microscopy which has unique advantages in observation of biological samples are reviwed. Some types of the x-ray microscopes have now resolution better than 0.1μm, exceeding that of light microscope, and are capable of quick imaging of rather thick (1-10μm) hydrated samples with x-rays in the region of water window (2.3-4.3nm). Future problems related to radiation damage and thermal diffusion in observation of hydrated sample are briefly introduced.
著者
太田 元規 福地 佐斗志 小池 亮太郎
出版者
一般社団法人 日本生物物理学会
雑誌
生物物理 (ISSN:05824052)
巻号頁・発行日
vol.57, no.2, pp.085-089, 2017 (Released:2017-03-30)
参考文献数
16

Protein-protein interactions are fundamental for all biological phenomena. The hub proteins interacting with a number of partner proteins play the vital role in the protein-protein interaction network. We investigated the subcellular localization of proteins in the network, and found that the proteins localized in the multiple subcellular compartments, especially the nucleus and cytoplasm, tend to be hub proteins. Examination on keywords associated with the proteins suggested that those related to post-translational modifications (PTMs) and transcriptions contributed to numerous interactions. Triggered by PTMs in the intrinsically disordered regions, they change interaction partners in the protein complex, and are translocated from cytoplasm to nucleus.