Edirisinghe Praneeth D, Moore Jerry F, Skinner-Nemec Kelly A, Lindberg Carl, Giometti Carol S, Veryovkin Igor V, Hunt Jerry E, Pellin Michael J, Hanley Luke
Department of Chemistry, University of Illinois at Chicago, Chicago, Illinois 60607-7061, USA.
Anal Chem. 2007 Jan 15;79(2):508-14. doi: 10.1021/ac0615605.
A novel analytical method based on laser desorption postionization mass spectrometry (LDPI-MS) was developed to investigate the competence and sporulation factor-a pentapeptide of amino acid sequence ERGMT-within intact Bacillus subtilis biofilms. Derivatization of the neat ERGMT peptide with quinoline- and anthracene-based tags was separately used to lower the peptide ionization potential and permit direct ionization by 7.87-eV vacuum ultraviolet radiation. The techniques of mass shifting and selective ionization of the derivatized peptide were combined here to permit detection of ERGMT peptide within intact biofilms by LDPI-MS, without any prior extraction or chromatographic separation. Finally, imaging MS specific to the derivatized peptide was demonstrated on an intact biofilm using LDPI-MS. The presence of ERGMT in the biofilms was verified by bulk extraction/LC-MS. However, MALDI imaging MS analyses were unable to detect ERGMT within intact biofilms.
开发了一种基于激光解吸后电离质谱（LDPI-MS）的新型分析方法，用于研究完整枯草芽孢杆菌生物膜中的活性和孢子形成因子——氨基酸序列为ERGMT的五肽。分别使用基于喹啉和蒽的标签对纯ERGMT肽进行衍生化，以降低肽的电离电位，并允许通过7.87 eV真空紫外辐射进行直接电离。在此将衍生化肽的质量转移和选择性电离技术相结合，以通过LDPI-MS在完整生物膜中检测ERGMT肽，无需任何预先提取或色谱分离。最后，使用LDPI-MS在完整生物膜上展示了衍生化肽特异性的成像质谱。通过大量提取/液相色谱-质谱法验证了生物膜中ERGMT的存在。然而，基质辅助激光解吸电离成像质谱分析无法在完整生物膜中检测到ERGMT。
