摘要
目的Darobactin(达罗巴汀)是一类经核糖体合成的翻译后修饰肽,该七肽具有独特的稠和双环结构,本研究建立了系统的基于高分辨质谱的darobactin组分的结构解析策略。方法依据文献中报道的在高能碰撞裂解(HCD)和碰撞诱导裂解(CID)模式下获得的一级及二级高分辨质谱数据,以碎片离子结构式的方式呈现了darobactin A的裂解途径,并修正了文献中部分碎片离子结构和质荷比的错误。针对特殊的双环结构,本文提出了基于生物合成路径的“逆向裂解途径”来确证1位和3位色氨酸之间因醚键断裂而生成的特征离子,并首次解析出包含特殊碳碳键的色氨酸-赖氨酸的碎片离子,为判断5位色氨酸被其他氨基酸(如精氨酸)取代提供了直接证据。结果建立了系统的darobactin A的结构解析策略,并以darobactin B/D/E的碎片离子加以验证,从理论上推导了其他darobacitn组分如C和F的特征离子。结论本文为快速判定darobactin新组分及其前体肽的结构提供了研究基础。
Objective Darobactin,which is a heptapeptide with unique condensed and bicyclic scaffold,belongs to a class of post-translational modified peptide synthesized by ribosome.In this study,a systematic structure analysis strategy for darobactin components based on high-resolution mass spectrometry was established.Methods Based on the m/z of adduct ions and fragment ions obtained in HCD and CID modes reported in the literature,a systematic structural analysis strategy based on high-resolution tandem mass spectrometry was established.The fragmentation pathway of darobactin A is presented in the form of fragment ions'structures.The errors in the structure and m/z of some fragment ions in the literature were corrected.It is proposed an idea of“reversed fragmentation pathway”based on the biosynthetic pathway to confirm the characteristic ions formed by the C-O-C bond breaking between tryptophan1 and tryptophan3 of the special bicyclic scaffold.Besides,the fragment ions of tryptophan3-lysine5 residue containing special C-C bond were characterized for the first time,providing direct evidence for judging whether tryptophan5 is replaced by other amino acids(such as arginine).Results The established structural analysis strategy can be reasonably used to determine the structure of known darobactin components(such as B/D/E),and can predict the fragment ions of homologous components(such as darobactin C/F,no MS/MS is given in the references).Conclusion This study provides a resolution for rapid determination of the structure of new components of darobactin and its precursor peptides.
作者
张含智
田振华
罗煜
秦东光
郭锋
Zhang Han-zhi;Tian Zhen-hua;Luo Yu;Qin Dong-guang;Guo Feng(Abiochem Biotechnology Co.,Ltd,Shanghai 200241)
出处
《中国抗生素杂志》
CAS
CSCD
北大核心
2023年第6期649-656,共8页
Chinese Journal of Antibiotics
