Special proton-gradient-transfer acid complexes （PGTACs） in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the prot...Special proton-gradient-transfer acid complexes （PGTACs） in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterifica- tion of terpenols. These PGTACs are ＂reaction-induced self-separation catalysts＂ and can be easily reused. The kinetics with PGTACs as catalyst in the esterification of geraniol were also studied for use in engineering design.展开更多
The ATP synthase （having a typical subunit composition of α3β3γeab2c8-15） employs an intriguing rotary mechanism for the generation of ATP from ADP and Pi, using energy stored in a transmembrane proton gradient. ...The ATP synthase （having a typical subunit composition of α3β3γeab2c8-15） employs an intriguing rotary mechanism for the generation of ATP from ADP and Pi, using energy stored in a transmembrane proton gradient. The conventional rotary model, although being generally accepted, remains difficult to explain certain experimental observations. Here we propose an alterna- tive rotary model for the ATP synthase such that what rotates is the catalytic α3β3 cylinder rather than the central stalk and the membrane-embedded c-ring. Specifically, the membrane translocation of protons would induce a cycled conformational change in the c-ring, leading to a reciprocating motion of the attached central stalk, which in turn drives the unidirectional rotation of the α3β3 cylinder. Such a reciprocating motion-driven rotation mechanism is somehow analogous to the working mechanism of a retractable click ballpoint pen. Our new model not only explains the experimental observations that have been difficult to reconcile with the conventional model but also avoids its theoretical illogicality.展开更多
基金supported by the National Natural Science Foundation of China (21376115, 21576129)~~
文摘Special proton-gradient-transfer acid complexes （PGTACs） in which the bonded protons are not equivalent and have gradients in transfer ability, acidity, and reactivity were reported. The acidity gradient of the protons gave the PGTACs excellent catalytic activity and selectivity in the esterifica- tion of terpenols. These PGTACs are ＂reaction-induced self-separation catalysts＂ and can be easily reused. The kinetics with PGTACs as catalyst in the esterification of geraniol were also studied for use in engineering design.
基金supported by research grants from the National Basic Research Program of China(2012CB917300 to Zengyi Chang and Xinmiao Fu)the National Natural Science Foundation of China(31470766 and 31170738 to ZYC31270804 and 31570778 to Xinmiao Fu)
文摘The ATP synthase （having a typical subunit composition of α3β3γeab2c8-15） employs an intriguing rotary mechanism for the generation of ATP from ADP and Pi, using energy stored in a transmembrane proton gradient. The conventional rotary model, although being generally accepted, remains difficult to explain certain experimental observations. Here we propose an alterna- tive rotary model for the ATP synthase such that what rotates is the catalytic α3β3 cylinder rather than the central stalk and the membrane-embedded c-ring. Specifically, the membrane translocation of protons would induce a cycled conformational change in the c-ring, leading to a reciprocating motion of the attached central stalk, which in turn drives the unidirectional rotation of the α3β3 cylinder. Such a reciprocating motion-driven rotation mechanism is somehow analogous to the working mechanism of a retractable click ballpoint pen. Our new model not only explains the experimental observations that have been difficult to reconcile with the conventional model but also avoids its theoretical illogicality.
