Owing to their diverse coordination patterns and catalytic mechanisms,non-heme iron-dependent dioxygenases catalyze a variety of biochemical reactions involved in the synthesis of numerous natural products and valuabl...Owing to their diverse coordination patterns and catalytic mechanisms,non-heme iron-dependent dioxygenases catalyze a variety of biochemical reactions involved in the synthesis of numerous natural products and valuable compounds.Recently,we discovered a novel and atypical non-heme iron-dependent dioxygenase,BTG13,that features a unique coordination center consisting of four histidines and a carboxylated lysine(Kcx).This enzyme catalyzes the C–C bond cleavage of anthraquinone through two unconventional steps,with modified Kcx playing a key role in facilitating these processes,as revealed by molecular dynamics simulations and quantum chemical calculations.Phylogenetic analyses and other studies suggest that BTG13-related metalloenzymes are widespread in various organisms.Here,we highlight the significance of this new class of non-heme iron-dependent oxygenases and their potential as novel tools for practical applications in synthetic biology.展开更多
Purpose To analyze the inter-limb coordination patterns and energy recovery of elite cross-country skiers performing double poling(DP).Methods Thirty-three elite athletes in three track sections of FIS-WC races,with d...Purpose To analyze the inter-limb coordination patterns and energy recovery of elite cross-country skiers performing double poling(DP).Methods Thirty-three elite athletes in three track sections of FIS-WC races,with different slopes(2°,0°and−1.5°).Stereo vision capture system(50 Hz cameras)and 3D analysis were used to extract:kinematic parameters(center of gravity,veloc-ity);joint angles and angular velocities;energy(potential and kinetic)and energy recovery indices R% and R(t)during the entire DP cycle and within poling(R_(pol))and swing phase(R_(swi)).Results Average race velocity of the centre of gravity(V_(ave))significantly varied according to slopes(5.4,7.3 and 8.3 m/s).This correlated with differences in the angular velocities of the most relevant joints.Elbow flexion angular velocity in the early portion of poling phase was higher according to the slope variations(−137,−171 and−202 deg/s,for the slopes 2°,0°and−1.5°,respectively),indicating the possible modulation of muscular stretch shortening cycle(SSC).A similar trend was observed for shoulder angular velocity which increased during poling phase,and for knee extension velocity during swing phase,and for knee extension velocity during swing phase.R%decreased significantly for the−1.5°slope(32%and 24%vs.15%);R(t)was higher for the Rswi.Significant differences were observed in trunk-elbow,trunk-shoulder,trunk-knee and elbow-shoulder patterns for the−1.5°slope with respect to the others.Conclusions Despite the modest variation of the track’s slope,the effects on propulsion and recovery strategies were different.展开更多
基金funded by the National Natural Science Foundation of China(32270082 and 22207044)the Natural Science Foundation of Jiangsu Province(BK20202002)the Basic Research Program of Jiangsu and the Jiangsu Basic Research Center for Synthetic Biology(BK20233003).
文摘Owing to their diverse coordination patterns and catalytic mechanisms,non-heme iron-dependent dioxygenases catalyze a variety of biochemical reactions involved in the synthesis of numerous natural products and valuable compounds.Recently,we discovered a novel and atypical non-heme iron-dependent dioxygenase,BTG13,that features a unique coordination center consisting of four histidines and a carboxylated lysine(Kcx).This enzyme catalyzes the C–C bond cleavage of anthraquinone through two unconventional steps,with modified Kcx playing a key role in facilitating these processes,as revealed by molecular dynamics simulations and quantum chemical calculations.Phylogenetic analyses and other studies suggest that BTG13-related metalloenzymes are widespread in various organisms.Here,we highlight the significance of this new class of non-heme iron-dependent oxygenases and their potential as novel tools for practical applications in synthetic biology.
文摘Purpose To analyze the inter-limb coordination patterns and energy recovery of elite cross-country skiers performing double poling(DP).Methods Thirty-three elite athletes in three track sections of FIS-WC races,with different slopes(2°,0°and−1.5°).Stereo vision capture system(50 Hz cameras)and 3D analysis were used to extract:kinematic parameters(center of gravity,veloc-ity);joint angles and angular velocities;energy(potential and kinetic)and energy recovery indices R% and R(t)during the entire DP cycle and within poling(R_(pol))and swing phase(R_(swi)).Results Average race velocity of the centre of gravity(V_(ave))significantly varied according to slopes(5.4,7.3 and 8.3 m/s).This correlated with differences in the angular velocities of the most relevant joints.Elbow flexion angular velocity in the early portion of poling phase was higher according to the slope variations(−137,−171 and−202 deg/s,for the slopes 2°,0°and−1.5°,respectively),indicating the possible modulation of muscular stretch shortening cycle(SSC).A similar trend was observed for shoulder angular velocity which increased during poling phase,and for knee extension velocity during swing phase,and for knee extension velocity during swing phase.R%decreased significantly for the−1.5°slope(32%and 24%vs.15%);R(t)was higher for the Rswi.Significant differences were observed in trunk-elbow,trunk-shoulder,trunk-knee and elbow-shoulder patterns for the−1.5°slope with respect to the others.Conclusions Despite the modest variation of the track’s slope,the effects on propulsion and recovery strategies were different.
