Wiegant V M, Verhoef J, Burbach J P, van Amerongen A, Gaffori O, Sitsen J M, de Wied D
Life Sci. 1985 Jun 17;36(24):2277-85. doi: 10.1016/0024-3205(85)90316-9.
N alpha-acetyl-gamma-endorphin (Ac gamma E) was identified in the rat neurointermediate pituitary, based on its immunological properties, comigration with synthetic Ac gamma E on HPLC and resistance to aminopeptidase-M degradation. The peptide appeared to be the main form of gamma-endorphin (gamma E) in this tissue and in brain areas remote from the hypothalamus (hippocampus, septum, amygdala). The anterior pituitary, the hypothalamus and the thalamus contained almost exclusively the non-acetylated form of gamma E. In contrast to gamma E, Ac gamma E was completely devoid of specific affinity for brain opiate binding sites. Yet, the peptide mimicked gamma E in that it potently attenuated passive avoidance behaviour in rats, when injected topically into the nucleus accumbens. It is concluded that Ac gamma E is an endogenous neuropeptide with non-opioid biological activity. N alpha-acetylation may not merely represent a mechanism for the inactivation of opioid activities of endorphins, but rather allow the organism to select specific sets of biological activities that reside in the endorphin structure.
基于其免疫特性、在高效液相色谱（HPLC）上与合成的Nα-乙酰基-γ-内啡肽（AcγE）共迁移以及对氨肽酶-M降解的抗性，在大鼠神经中间叶垂体中鉴定出了Nα-乙酰基-γ-内啡肽（AcγE）。该肽似乎是该组织以及下丘脑以外脑区（海马体、隔区、杏仁核）中γ-内啡肽（γE）的主要形式。垂体前叶、下丘脑和丘脑几乎只含有非乙酰化形式的γE。与γE不同，AcγE对脑阿片结合位点完全没有特异性亲和力。然而，当局部注射到伏隔核时，该肽在减弱大鼠被动回避行为方面模仿了γE。得出的结论是，AcγE是一种具有非阿片类生物活性的内源性神经肽。Nα-乙酰化可能不仅代表一种使内啡肽阿片类活性失活的机制，而且还允许机体选择内啡肽结构中特定的生物活性组合。
