期刊名称：Proceedings of the National Academy of Sciences
印刷版ISSN：0027-8424
电子版ISSN：1091-6490
出版年度：1980
卷号：77
期号：6
页码：3374-3378
DOI：10.1073/pnas.77.6.3374
语种：English
出版社：The National Academy of Sciences of the United States of America
摘要：The entropy of activation for the synthesis of Ile-tRNA is high and positive. The only likely source of a high delta S is the loss of structured water as the enzyme . substrate complex moves toward the transition state. This requires a change in the orientation or nature of water-organizing residues in the interface between the enzyme . substrate complex and the water. Such changes, which may be some distance from the "active site," are coupled to the active site in such a way that the increased entropy and decreased free energy of the water--enzyme interface is available at the "active site" to reduce the free energy of activation. The effects of Hofmeister anions on KmS and KcatS are consistent with the entropy data.
