基质辅助激光解析电离质谱和电喷雾质谱共同快速确证达托霉素结构  

Fast Structure Confirmation of Daptomycin by Matrix-assisted Laser Desorption Ionization Mass Spectrometry and Electrospray Ionization Mass Spectrometry

作　　者：黄亚娟[1,2] 张拓[1,2] 韩治国[1,2] 孟晓光[1,2] 宋纯艳[1,2] 刘曙晨[3] 郑俊杰[1,2,3] 魏开华[1,2,3] 

机构地区：[1]北京正旦国际科技有限责任公司,北京102206 [2]北京蛋白质组研究中心,蛋白质组学国家重点实验室,国家蛋白质科学中心(北京),北京102206 [3]军事医学科学院放射与辐射医学研究所,北京100850

出　　处：《分析化学》2015年第1期63-68,共6页Chinese Journal of Analytical Chemistry

基　　金：国家高技术研究发展计划863项目(Nos.2012AA020205,2014AA020906);国家科技部传染病重大专项(No.2013ZX10002009001-001);国家重大科学仪器设备开发专项(No.2012YQ18011710)资助~~

摘　　要：运用基质辅助激光解析电离-飞行时间串联质谱(MALDI-TOF/TOF MS)和电喷雾-四级杆-飞行时间质谱(ESI-Q-TOF MS)快速确证环脂肽达托霉素的结构。首先,ESI检测达托霉素相对分子量为1619.7107,与理论值偏差0.0007。选择其双电荷峰m/z 809.848作为母离子进行ESI串联质谱(MS/MS)测定,成功匹配了达托霉素环外氨基酸序列C9H19CO-Trp-Asn-Asp。其次,优化Li OH裂解达托霉素的实验条件,以MALDITOF/TOF MS监测开环效果,获得95%以上的开环样本后,分别运用MALDI和ESI进行MS/MS测定,达托霉素开环产物的b+和y+全部被匹配,达托霉素全部氨基酸序列得到确证。最后,对开环产物的ESI-MS/MS条件进一步优化,获得了丰富的低端碎片离子,解析了脂肪酸链结构,并绘制了脂肪酸链的裂解图。本方法快速、简便、准确,是确证环脂肽类化合物结构的可靠方法。Matrix-assisted laser desorption ionization-time of flight tandem mass spectrometry（ MALDI-TOF /TOF MS） and electrospray ionization-quadrupole-time of flight mass spectrometry（ ESI-Q-TOF MS） were used to confirm the structure of cyclic lipopeptide daptomycin fastly. First,the relative molecular weight 1916. 7107 of daptomycin was measured by ESI with error 0. 0007. The sample＇s doubly charged peak m / z 809. 848 was selected as precursor ion for ESI-MS / MS analysis,and the exocyclic amino acid sequence C9H19CO-Trp-AsnAsp was successfully matched. Second, the experimental conditions of cleaving daptomycin by lithium hydroxide（ Li OH） were optimized and the ring-opened process was monitored by MALDI-TOF / TOF MS. After obtaining ring-opened product with purity of above 95%,the MS / MS measurements by MALDI and ESI were carried out. The b^＋ and y^＋ of ring-opened product were completely matched,which confirmed the amino acid sequence of daptomycin. Finally,ESI-MS / MS conditions of ring-opened product were further optimized to obtain more low mass fragment ions for analyzing the structure of fatty acid chain and the cleavage pattern of fat chain in mass spectrometry was proposed. The method was fast,convenient,accurate and reliable for identifying cyclic lipopeptide compounds.

关 键 词：达托霉素 环脂肽 串联质谱 电喷雾质谱 

分 类 号：O657.63[理学—分析化学]