Hydantoinase and N-carbamoylase play important rol es in the production of optically pure amino acids from racemic 5-monosubstitut ed hydantoins. In this report, hydantoinase and the N-carbamoylase from Burkh olderia ...Hydantoinase and N-carbamoylase play important rol es in the production of optically pure amino acids from racemic 5-monosubstitut ed hydantoins. In this report, hydantoinase and the N-carbamoylase from Burkh olderia cepecia.njut01 were purified to homogeneity by chromatography (Pharma cia Explorer 100 system). The substrate specificity, enantioselectivity, pH depe ndence of activity and temperature stability of the activity were characterized. The results show that the hydantoinase and N-carbamoylase induced from Burkh olderia cepecia.njut01 are both strict D-stereo selective enzymes. They both hydrolyze substrates with side chains containing aliphatic and aromatic res idues with higher activity and affinity toward aromatic than aliphatic substitu ted substrates. The hydantoinase is a homotetramer with subunit molecular weight near 52,000 and is active between pH 6.5 and 10 with an optimum near pH 9.0. The en zyme is active at temperatures up to 60°C, however,it appears instable at h ig her temperatures. The subunit molecular weight of N-carbamoylase is about 35KD. The N-carbamoylase is active in the pH range from 6.0 to 9.5. The optim-pH is 7.2 and the optimizing bioconversion temperature of the N-carbamyolase is 52 °C.展开更多
在交际过程中,说话者有意或无意使用的语用模糊往往会产生衍生的意义,从而造成更丰富的交际效果。戏剧作品中存在的语用模糊现象能够帮助读者和观众领略到戏剧更多的潜文本内容。探讨《李尔王》中的正、反面人物语言的语用模糊现象不仅...在交际过程中,说话者有意或无意使用的语用模糊往往会产生衍生的意义,从而造成更丰富的交际效果。戏剧作品中存在的语用模糊现象能够帮助读者和观众领略到戏剧更多的潜文本内容。探讨《李尔王》中的正、反面人物语言的语用模糊现象不仅让读者和观众重新认识剧中相关人物形象,而且还能获知语用模糊在该剧中对于戏剧情节"突转"(reversal of the situation)、人物命运的变化、悬念的设置以及情节整体性方面的新的、重要的作用。展开更多
文摘Hydantoinase and N-carbamoylase play important rol es in the production of optically pure amino acids from racemic 5-monosubstitut ed hydantoins. In this report, hydantoinase and the N-carbamoylase from Burkh olderia cepecia.njut01 were purified to homogeneity by chromatography (Pharma cia Explorer 100 system). The substrate specificity, enantioselectivity, pH depe ndence of activity and temperature stability of the activity were characterized. The results show that the hydantoinase and N-carbamoylase induced from Burkh olderia cepecia.njut01 are both strict D-stereo selective enzymes. They both hydrolyze substrates with side chains containing aliphatic and aromatic res idues with higher activity and affinity toward aromatic than aliphatic substitu ted substrates. The hydantoinase is a homotetramer with subunit molecular weight near 52,000 and is active between pH 6.5 and 10 with an optimum near pH 9.0. The en zyme is active at temperatures up to 60°C, however,it appears instable at h ig her temperatures. The subunit molecular weight of N-carbamoylase is about 35KD. The N-carbamoylase is active in the pH range from 6.0 to 9.5. The optim-pH is 7.2 and the optimizing bioconversion temperature of the N-carbamyolase is 52 °C.
文摘在交际过程中,说话者有意或无意使用的语用模糊往往会产生衍生的意义,从而造成更丰富的交际效果。戏剧作品中存在的语用模糊现象能够帮助读者和观众领略到戏剧更多的潜文本内容。探讨《李尔王》中的正、反面人物语言的语用模糊现象不仅让读者和观众重新认识剧中相关人物形象,而且还能获知语用模糊在该剧中对于戏剧情节"突转"(reversal of the situation)、人物命运的变化、悬念的设置以及情节整体性方面的新的、重要的作用。
