Cellular metabolism is a very complex process. The biochemical pathways are fundamental structures of biology. These pathways possess a number of regeneration steps which facilitate energy shuttling on a massive scale...Cellular metabolism is a very complex process. The biochemical pathways are fundamental structures of biology. These pathways possess a number of regeneration steps which facilitate energy shuttling on a massive scale. This facilitates the biochemical pathways to sustain the energy currency of the cells. This concept has been mimicked using electronic circuit components and it has been used to increase the efficiency of bio-energy generation. Six of the carbohydrate biochemical pathways have been chosen in which glycolysis is the principle pathway. All the six pathways are interrelated and coordinated in a complex manner. Mimic circuits have been designed for all the six biochemical pathways. The components of the metabolic pathways such as enzymes, cofactors etc., are substituted by appropriate electronic circuit components. Enzymes are related to the gain of transistors by the bond dissociation energies of enzyme-substrate molecules under consideration. Cofactors and coenzymes are represented by switches and capacitors respectively. Resistors are used for proper orientation of the circuits. The energy obtained from the current methods employed for the decomposition of organic matter is used to trigger the mimic circuits. A similar energy shuttle is observed in the mimic circuits and the percentage rise for each cycle of circuit functioning is found to be 78.90. The theoretical calculations have been made using a sample of domestic waste weighing 1.182 kg. The calculations arrived at finally speak of the efficiency of the novel methodology employed.展开更多
Ryanodine receptors are ion channels that allow for the release of Ca2+ from the endoplasmic or sarcoplasmic reticulum.They are expressed in many different cell types but are best known for their predominance in skele...Ryanodine receptors are ion channels that allow for the release of Ca2+ from the endoplasmic or sarcoplasmic reticulum.They are expressed in many different cell types but are best known for their predominance in skeletal and cardiac myocytes,where they are directly involved in excitation-contraction coupling.With molecular weights exceeding 2 MDa,Ryanodine Receptors are the largest ion channels known to date and present major challenges for structural biology.Since their discovery in the 1980s,significant progress has been made in understanding their behaviour through multiple structural methods.Cryo-electron microscopy reconstructions of intact channels depict a mushroom-shaped structure with a large cytoplasmic region that pre-sents many binding sites for regulatory molecules.This region undergoes significant motions during opening and closing of the channel,demonstrating that the Ryanodine Receptor is a bona fide allosteric protein.High-resolution structures through X-ray crystallography and NMR currently cover～11% of the entire protein.The combination of high-and low-resolution methods allows us to build pseudo-atomic models.Here we present an overview of the electron microscopy,NMR,and crystallographic analyses of this membrane protein giant.展开更多
光系统Ⅱ(photosystemⅡ,PSⅡ)是位于植物、藻类和蓝细菌等放氧光合生物类囊体膜上的重要超分子复合物,它可通过捕获光能用于激发反应中心的电荷分离并驱动电子传递过程,在常温常压下可将水分子裂解产生氧气和质子.植物光系统Ⅱ的外周...光系统Ⅱ(photosystemⅡ,PSⅡ)是位于植物、藻类和蓝细菌等放氧光合生物类囊体膜上的重要超分子复合物,它可通过捕获光能用于激发反应中心的电荷分离并驱动电子传递过程,在常温常压下可将水分子裂解产生氧气和质子.植物光系统Ⅱ的外周存在主要和次要捕光复合物Ⅱ(major and minor light-harvesting complexⅡ,LHCⅡ),它们负责吸收光能并向光系统Ⅱ传递激发能,并且还参与非光化学淬灭和状态转换相关的捕光调节过程.近年来,围绕光系统Ⅱ和LHCⅡ的结构生物学研究取得了一系列重要进展,本文总结了PSⅡ、LHCⅡ和二者共同组成的PSII-LHCII超级复合物的结构生物学研究历程以及最新进展,并对该领域的未来研究方向做出展望.展开更多
文摘Cellular metabolism is a very complex process. The biochemical pathways are fundamental structures of biology. These pathways possess a number of regeneration steps which facilitate energy shuttling on a massive scale. This facilitates the biochemical pathways to sustain the energy currency of the cells. This concept has been mimicked using electronic circuit components and it has been used to increase the efficiency of bio-energy generation. Six of the carbohydrate biochemical pathways have been chosen in which glycolysis is the principle pathway. All the six pathways are interrelated and coordinated in a complex manner. Mimic circuits have been designed for all the six biochemical pathways. The components of the metabolic pathways such as enzymes, cofactors etc., are substituted by appropriate electronic circuit components. Enzymes are related to the gain of transistors by the bond dissociation energies of enzyme-substrate molecules under consideration. Cofactors and coenzymes are represented by switches and capacitors respectively. Resistors are used for proper orientation of the circuits. The energy obtained from the current methods employed for the decomposition of organic matter is used to trigger the mimic circuits. A similar energy shuttle is observed in the mimic circuits and the percentage rise for each cycle of circuit functioning is found to be 78.90. The theoretical calculations have been made using a sample of domestic waste weighing 1.182 kg. The calculations arrived at finally speak of the efficiency of the novel methodology employed.
基金funded by the CIHR(operating grant 84350)the Heart and Stroke Foundation of Canadaa CIHR new investigator and a Michael Smith Foundation for Health Research Scholar
文摘Ryanodine receptors are ion channels that allow for the release of Ca2+ from the endoplasmic or sarcoplasmic reticulum.They are expressed in many different cell types but are best known for their predominance in skeletal and cardiac myocytes,where they are directly involved in excitation-contraction coupling.With molecular weights exceeding 2 MDa,Ryanodine Receptors are the largest ion channels known to date and present major challenges for structural biology.Since their discovery in the 1980s,significant progress has been made in understanding their behaviour through multiple structural methods.Cryo-electron microscopy reconstructions of intact channels depict a mushroom-shaped structure with a large cytoplasmic region that pre-sents many binding sites for regulatory molecules.This region undergoes significant motions during opening and closing of the channel,demonstrating that the Ryanodine Receptor is a bona fide allosteric protein.High-resolution structures through X-ray crystallography and NMR currently cover～11% of the entire protein.The combination of high-and low-resolution methods allows us to build pseudo-atomic models.Here we present an overview of the electron microscopy,NMR,and crystallographic analyses of this membrane protein giant.
文摘光系统Ⅱ(photosystemⅡ,PSⅡ)是位于植物、藻类和蓝细菌等放氧光合生物类囊体膜上的重要超分子复合物,它可通过捕获光能用于激发反应中心的电荷分离并驱动电子传递过程,在常温常压下可将水分子裂解产生氧气和质子.植物光系统Ⅱ的外周存在主要和次要捕光复合物Ⅱ(major and minor light-harvesting complexⅡ,LHCⅡ),它们负责吸收光能并向光系统Ⅱ传递激发能,并且还参与非光化学淬灭和状态转换相关的捕光调节过程.近年来,围绕光系统Ⅱ和LHCⅡ的结构生物学研究取得了一系列重要进展,本文总结了PSⅡ、LHCⅡ和二者共同组成的PSII-LHCII超级复合物的结构生物学研究历程以及最新进展,并对该领域的未来研究方向做出展望.
