化学学报 ›› 2004, Vol. 62 ›› Issue (21): 2200-2204. 上一篇    下一篇

研究简报

环脂肽氨基酸顺序的质谱测定

杨世忠, 牟伯中, 吕应年, 陈涛   

  1. 华东理工大学化学与制药学院, 上海, 200237
  • 投稿日期:2004-02-03 修回日期:2004-05-08 发布日期:2014-02-17
  • 通讯作者: bzmu@ecust.edu.cn
  • 作者简介:牟伯中,E-mail:bzmu@ecust.edu.cn;Tel&Fax:021-64252063
  • 基金资助:
    国家自然科学基金(No.59974014)、高校博士点基金(No.20030251002)、教育部重点项目(No.03071)和上海市教委资助项目.

MS Determination of the Sequence of Amino Acids in a Cyclic Lipopeptide

YANG Shi-Zhong, MU Bo-Zhong, LÜ Ying-Nian, CHEN Tao   

  1. School of Chemistry and Pharmaceutics, East China University of Science and Technology, Shanghai 200237
  • Received:2004-02-03 Revised:2004-05-08 Published:2014-02-17

从一株枯草芽孢杆菌的培养液中分离得到一种生物表面活性剂,红外光谱、茚三酮显色及质谱分析表明它是一种具有环状结构的脂肽.质谱显示脂肽的脂肪酸部分为β-羟基脂肪酸;氨基酸分析表明肽部分由4个亮氨酸、1个天门东氨酸、1个缬氨酸和1个谷氨酸组成.利用串联飞行时间质谱测定了环脂肽的分子量及质谱图.根据分子量的氮规则和质谱碎片产生的简单断裂、双氢转移机制、McLafferty等单氢重排机制,直接确定了未水解的环脂肽中脂肪链的长度以及氨基酸连接的顺序.质谱中的峰可以得到合理解释.确定了该环脂肽的环状结构.

关键词: 生物表面活性剂, 脂肽, 环状结构, 质谱, 氨基酸顺序

A cyclic lipopeptide biosurfactant was separated from the culture supernatant of Bacillus subtilis HS0121 isolated in our laboratory from stratum fluids in an oil field. Its molecular structure was determined by TOF MS/MS combined with IR spectrometry, ninhydrin coloration and amino acid analyses. The experiment shows that the aliphatic chain in the cyclic lipopeptide is a β hydroxy fatty acid determined by mass spectrometry and the peptide chain consists of four Leu, one Asp, one Val and one Glu amino acids determined by amino acid analyses. The molecular weight and MS spectra of the cyclic lipopeptide were obtained by TOF MS/MS. Consequently, The length of the aliphatic chain and the sequence of amino acids in the cyclic lipopeptide before hydrolysis were directly determined according to the N rules in molecular weight, mechanism of basic cleavage, double H and single H transfer including McLafferty rearrangement. Results demonstrate that TOF MS/MS is a feasible way in determination of sequences of amino acids of lipopeptide and its corresponding structure.

Key words: biosurfactant, lipopeptide, cyclic structure, TOF MS/MS, sequence of amino acid