Cauet G, Friboulet A, Thomas D
Biochim Biophys Acta. 1987 Apr 30;912(3):338-42. doi: 10.1016/0167-4838(87)90037-9.
Native horse serum butyrylcholinesterase (acylcholine acylhydrolase; EC 3.1.1.8) is a tetrameric enzyme which can dissociate after a limited proteolysis by trypsin into three additional molecular forms, including the monomeric entity. The trypsin-generated monomer of butyrylcholinesterase, isolated by ultracentrifugation on sucrose gradient, is stable and allows the relations between the polymeric structure of butyrylcholinesterase and its kinetic characteristics to be approached, e.g., substrate activation and complex thermal denaturation curves. The trypsin-generated monomer of butyrylcholinesterase behaves with identical kinetic parameter values as the native tetrameric enzyme. On the other hand, the thermal denaturation of the native tetrameric butyrylcholinesterase does not follow first-order kinetics, but may be described by a sum of exponential terms. This behavior is not due to the polymeric nature of butyrylcholinesterase but seems to be related to a structural heterogeneity induced by the heat treatment.
天然马血清丁酰胆碱酯酶（酰基胆碱酰基水解酶；EC 3.1.1.8）是一种四聚体酶，经胰蛋白酶有限水解后可解离为三种其他分子形式，包括单体形式。通过蔗糖梯度超速离心分离得到的胰蛋白酶生成的丁酰胆碱酯酶单体是稳定的，能够研究丁酰胆碱酯酶的聚合结构与其动力学特征之间的关系，例如底物激活和复杂的热变性曲线。胰蛋白酶生成的丁酰胆碱酯酶单体表现出与天然四聚体酶相同的动力学参数值。另一方面，天然四聚体丁酰胆碱酯酶的热变性不遵循一级动力学，而是可以用指数项之和来描述。这种行为并非由于丁酰胆碱酯酶的聚合性质，而是似乎与热处理诱导的结构异质性有关。
