RUI: Evolution of Cholinesterase In Vivo and In Vitro

小行星9319354 每当一个人移动肌肉时，乙酰胆碱酯酶通过分解神经递质乙酰胆碱来确保肌肉放松，乙酰胆碱是由神经系统释放的，启动肌肉收缩过程。 因此，乙酰胆碱酯酶是所有运动活动所必需的，包括写作和说话。 除了乙酰胆碱酯酶，人类还拥有另一种进化上相关的酶，丁酰胆碱酯酶，具有相似但不同的特征。 与乙酰胆碱酯酶相反，这种酶的功能尚不清楚。 事实上，有些人完全缺乏这种酶，但看起来正常。 有人认为，丁酰胆碱酯酶作为摄入的神经毒素的清除剂，并在神经系统的胚胎发育中发挥作用。 虽然人类和其他高等脊椎动物都有这两种胆碱酯酶，但低等脊椎动物似乎只有一种，即乙酰胆碱酯酶。 无脊椎动物也只有一种胆碱酯酶;然而，它既不是乙酰胆碱酯酶，也不是丁酰胆碱酯酶，而是一种具有中间特性的酶。 有人说，“生物学中没有什么是有意义的，除非从进化的角度来看。“因此，为了澄清这两种胆碱酯酶在人类中的作用，特别是丁酰胆碱酯酶，Pezzementi博士正在追踪这两种酶的进化，利用生物化学、药理学和重组DNA技术研究选定生物体中胆碱酯酶的结构和功能，其中发生了从单一中间胆碱酯酶到两种不同胆碱酯酶的转变。 将这些信息与所讨论的生物体的生物学相结合，可以为这些酶的生理功能提供进一步的线索。 ***

9319354 Pezzementi Whenever one moves a muscle, the enzyme acetylcholinesterase insures that the muscle will relax by breaking down the neurotransmitter acetylcholine, which is released by the nervous system initiating the processes of muscle contraction. Thus, acetylcholinesterase is required for all motor activity, including writing and speech. In addition to acetylcholinesterase, humans possess another evolutionarily related enzyme, butyrylcholinesterase, with similar, but distinct, characteristics. In contrast to acetylcholinesterase, the function of this enzyme is unknown. In fact, there appear to be individuals who lack this enzyme entirely, yet appear normal. It has been suggested that butyrylcholinesterase acts as a scavenger of ingested neurotoxins and that it plays a role in the embryological development of the nervous system. Although humans and other higher vertebrates possess both cholinesterases, lower vertebrates appear to possess only one, acetylcholinesterase. Invertebrates also possess only one cholinesterase; however, it is neither acetylcholinesterase, nor butyrylcholinesterase, but an enzyme with intermediate characteristics. It has been stated that "nothing in biology makes sense, except in the light of evolution." Thus, in an attempt to clarify the roles of the two cholinesterases in humans, in particular butyrylcholinesterase, Dr. Pezzementi is tracing the evolution of the two enzymes, using the techniques of biochemistry, pharmacology, and recombinant DNA technology to study the structure and function of cholinesterases in selected organisms, where the transition from a single intermediate cholinesterase to two distinct cholinesterases occurs. Integration of this information with the biology of the organisms in question could provide further clues about the physiological functions of these enzymes. ***