引入局部条件并半格 (简记为 L cusl)及其理想完备化等概念 .证明了 :任一代数 L domain的紧元集是 L cusl;任一代数 L domain是其紧元集赋予 Alexandrov拓扑时的 Sober化 ;任一 L cusl的理想完备化是代数 L domain,从而得到了代数 L do...引入局部条件并半格 (简记为 L cusl)及其理想完备化等概念 .证明了 :任一代数 L domain的紧元集是 L cusl;任一代数 L domain是其紧元集赋予 Alexandrov拓扑时的 Sober化 ;任一 L cusl的理想完备化是代数 L domain,从而得到了代数 L domain的表示定理 .还证明了 Scott连续映射为态射的代数 L domain范畴为 L cusl与单调映射作成的范畴的反射子范畴 .展开更多
To enhance the relative movement of domains, we inserted a random sequence of fifteen-peptide into the three domains of L-aspartase. By means of directed screening, the three isoforms of monomeric, dimmeric and tetram...To enhance the relative movement of domains, we inserted a random sequence of fifteen-peptide into the three domains of L-aspartase. By means of directed screening, the three isoforms of monomeric, dimmeric and tetrameric enzymes were obtained. Compared to the wild-type tetrameric L-asparease, these mutants remained 19.7%, 42.3%, and 92% of the enzyme activity, respectively. Moreover, the examination of enzyme properties revealed that their k_ cat and K_M changed in varying degrees, and the optimum pH shifted towards acidic pH, while the dependence of the activity of enzyme on Mg 2+ concentration and thermostability increased. Therefore this strategy provides a novel approach to directed evolution of enzymes.展开更多
文摘引入局部条件并半格 (简记为 L cusl)及其理想完备化等概念 .证明了 :任一代数 L domain的紧元集是 L cusl;任一代数 L domain是其紧元集赋予 Alexandrov拓扑时的 Sober化 ;任一 L cusl的理想完备化是代数 L domain,从而得到了代数 L domain的表示定理 .还证明了 Scott连续映射为态射的代数 L domain范畴为 L cusl与单调映射作成的范畴的反射子范畴 .
文摘To enhance the relative movement of domains, we inserted a random sequence of fifteen-peptide into the three domains of L-aspartase. By means of directed screening, the three isoforms of monomeric, dimmeric and tetrameric enzymes were obtained. Compared to the wild-type tetrameric L-asparease, these mutants remained 19.7%, 42.3%, and 92% of the enzyme activity, respectively. Moreover, the examination of enzyme properties revealed that their k_ cat and K_M changed in varying degrees, and the optimum pH shifted towards acidic pH, while the dependence of the activity of enzyme on Mg 2+ concentration and thermostability increased. Therefore this strategy provides a novel approach to directed evolution of enzymes.
