Koelle G B, Massoulié J, Eugène D, Melone M A
Laboratoire de Neurobiologie, Ecole Normale Supérieure, Paris, France.
Proc Natl Acad Sci U S A. 1988 Mar;85(5):1686-90. doi: 10.1073/pnas.85.5.1686.
Normal and preganglionically denervated cat superior cervical ganglia were sectioned and cultured for 24 or 48 hr, with or without preliminary inactivation of acetylcholinesterase, and in the presence or absence of 10(-5) M glycyl-L-glutamine. They were then homogenized, and the molecular forms of acetylcholinesterase were analyzed by sucrose gradient sedimentation. We observed an increased proportion of the globular monomeric G1 form, and to a lesser extent of the dimeric G2 and tetrameric membranous G4 forms, of acetylcholinesterase in the glycyl-L-glutamine-treated compared with the control cultures. There was only a small increase in the total acetylcholinesterase activity and no significant variation in the activity of the metabolic enzyme lactate dehydrogenase. It therefore seems likely that glycyl-L-glutamine, or the endogenous neurotrophic factor, maintains acetylcholinesterase in the preganglionically denervated ganglia in vivo by specifically increasing the biosynthesis of the monomeric G1 form, but not that of other proteins; these trophic factors do not seem to promote the polymerization of G1 into the more complex G2 and G4 forms.
将正常和节前神经去支配的猫颈上神经节进行切片，并在有或没有预先使乙酰胆碱酯酶失活的情况下，以及在存在或不存在10^(-5) M甘氨酰-L-谷氨酰胺的情况下培养24或48小时。然后将它们匀浆，并通过蔗糖梯度沉降分析乙酰胆碱酯酶的分子形式。我们观察到，与对照培养物相比，在甘氨酰-L-谷氨酰胺处理的培养物中，乙酰胆碱酯酶的球状单体G1形式的比例增加，二聚体G2和四聚体膜状G4形式的比例增加程度较小。总乙酰胆碱酯酶活性仅略有增加，代谢酶乳酸脱氢酶的活性没有显著变化。因此，似乎甘氨酰-L-谷氨酰胺或内源性神经营养因子通过特异性增加单体G1形式的生物合成，而不是其他蛋白质的生物合成，在体内维持节前神经去支配神经节中的乙酰胆碱酯酶；这些营养因子似乎不会促进G1聚合成更复杂的G2和G4形式。
