多肽在生命过程中扮演着重要的角色,对其生理生化功能的研究与应用,离不开对单一多肽物质的需求,而化学合成法是获取目标多肽的最有效方法之一。对合成产物的分离与鉴定,是优化合成条件,以得到高产率的重要保证。以两种内源性神经肽亮氨酸脑啡肽和甲硫氨酸脑啡肽为模型,利用Fmoc固相多肽合成策略对其进行合成,并建立了HPLC-ESI-MS/MS新方法用于所制备的亮氨酸脑啡肽和甲硫氨酸脑啡肽的分离与结构鉴定。研究结果显示,主要合成产物均为目标多肽,副产物主要包括C端丢失1个氨基酸所形成的四肽,以及由于甲硫氨酸残基氧化而形成的含甲硫氨酸亚砜的多肽。该研究为高效合成含敏感氨基酸的生理活性多肽提供了新信息。
Peptides play an important role in life process. In this paper,two endogenous neuropeptides including methionine enkephalin and leucine enkephalin were selected as research targets. They were synthesized by Fmoc solid phase peptide synthesis strategy. An HPLC-ESI-MS/MS method was established to investigate the composition of synthetic peptides. The possible structure modifications during peptide synthesis procedures were also identified. The results showed that the main byproducts were incomplete peptides and oxidative peptides. Solutions for high efficient synthesis of methionine enkephalin and leucine encephalin were further proposed. This study provides new perspectives in rapid peptide structure identification and efficient bioactive peptide synthesis.