著者
高橋 大地
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.60, no.4, pp.254-255, 2020 (Released:2020-07-29)
被引用文献数
1
著者
庄司 光男 磯部 寛 重田 育照 中嶋 隆人 山口 兆
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.58, no.3, pp.127-133, 2018 (Released:2018-05-31)
参考文献数
30

Photosystems are natural energy conversion systems evolved for over 2,700 million years. Among the photosystems, photosystem II (PSII) catalyzes the light-driven water decomposition reaction with the production of O2, protons and electrons to reduce plastoquinone. The reaction is important not only for understanding natural photosynthesis but also for creating efficient artificial photosynthesis. In this review, PSII catalytic intermediate states and their reaction mechanisms elucidated by experimental and theoretical approaches are introduced mainly following the development of the X-ray crystallography. For the O2 formation mechanism, two representative mechanisms, acid-base and radical coupling, are explained. Finally, we discuss the geometrical and electronic structures of inorganic model complex in comparison with those of the native catalytic center in PSII.
著者
神谷 律
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.29, no.5, pp.231-236, 1989-09-25 (Released:2009-05-25)
参考文献数
25

The inner and outer dynein arms in eukaryotic flagella are key protein assemblies responsible for force production. Although the two types of arm have been believed to have similar properties, studies on newly isolated Chlamydomonas mutants lacking either of them indicate that they differ strikingly in structure and function; for example, flagella lacking the entire outer arms are motile, whereas those lacking the entire inner arm are nonmotile. These studies suggest that the inner and outer arms play different roles in flagellar motility, and raise a problem of how they cooperate to produce efficient flagellar beating.
著者
太和田 勝久
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.43, no.6, pp.264-269, 2003 (Released:2003-11-23)

A single processive and tightly-coupled molecular motor such as kinesin performs mechanical work by using the heat absorbed by the motor from the surroundings upon catalyzing spontaneously occurring ATP hydrolysis. This is a conclusion derived from a thermodynamic analysis of the mechano-chemical cycle of such single molecular motors together with an equation that relates work done by single molecular motors to the thermodynamics of ATP hydrolysis catalyzed by the motors. Analysis of motor models based on the thermodynamic approach leads to a general equation depicting the stepping motion of such molecular motors as a biased random walk.
著者
佐藤 智
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.39, no.4, pp.217-222, 1999-07-25 (Released:2000-04-12)
参考文献数
20

Endocytosis is involved in information-processing in many cell types. Recent research efforts revealed its regulatory mechanism at the synaptic terminus and regulated internalization of many G-protein coupled receptors and cell adhesion molecules. Moreover, an important break-through has been brought about by establishment of the usage of actin-dependent mechanisms. The drasitic advance in understanding of the molecular mechanism is now widening its biological significance as the global linkage among membrane traffic, cytoskeletal dynamics and signal transduction.
著者
小田 琢三
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.20, no.3, pp.163-173, 1980-05-25 (Released:2009-05-25)
参考文献数
128
著者
張 岩 今井 清博 小林 道頼
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.47, no.3, pp.167-173, 2007-05-25
参考文献数
13

The slope of the oxygen equilibrium curve (OEC) of mammalian-hemoglobin (Hb) is maximized at <i>S</i> (oxygen saturation) value of 0.38, and the slope of the <i>S</i> vs. <i>P</i>/<i>P</i><sub>50</sub> (<i>P</i> is partial oxygen pressure; <i>P</i><sub>50</sub> is <i>P</i> at <i>S</i> = 1/2) plot at a <i>P</i>/<i>P</i><sub>50</sub> value of 1 is one-forth that of the Hill-coefficient (<i>n</i>). OECs of mammalian Hbs are designed to have an identical optimal <i>P</i><sub>50</sub> value for O<sub>2</sub> delivery and the effectiveness of the Bohr shift (shift of OEC upon pH changes) at O<sub>2</sub> loading site. This fact is favorable for uptake and delivery of maximum amount of O<sub>2</sub> for fetal blood. To have the identical optimal <i>P</i><sub>50</sub> value for O<sub>2</sub> delivery and for the efficiency of the Bohr shift, the relationship, <i>P</i>aO<sub>2</sub>/<i>P</i>vO<sub>2</sub> = ((<i>n</i> + 1)/(<i>n</i> &minus; 1))<sup>2/n</sup>, is required to hold, where <i>P</i>aO<sub>2</sub> and <i>P</i>vO<sub>2</sub> are <i>P</i> for arterial and venous bloods, respectively.<br>
著者
阿久津 達也 ホセ・カルロス ナチェル・ディエズ
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.47, no.2, pp.086-092, 2007 (Released:2007-03-31)
参考文献数
17

Many real systems can be described as networks, composed of a set of nodes and a set of edges connecting the nodes. Interestingly, it has been found that most real networks have a common architecture, termed scale-free or broad-tail topology. Here we review key well-established concepts in network science: small world, scale-free network and network motif, with special emphasis on biological networks. Key mechanisms responsible for the emergence of the scale-free property are discussed along with a simple evolutionary model of protein-protein interaction networks.
著者
浜口 幸久
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.27, no.6, pp.262-267, 1987-11-25 (Released:2009-05-25)
参考文献数
36

Microfilaments compose microvilli, fertilization cone, cortical layer, and contractile ring in sea urchin eggs, and microtubules compose sperm aster and mitotic apparatus. These cytoskeletal structures spatially and temporally change during fertilization and cleavage, which has become clear at molecular level using fluorescent analogues of actin and tubulin.