Merck Stiftungsprofessur für Molekulare Biotechnologie, Instititut für Molekulare Biowissenschaften, Goethe Universität Frankfurt, Max-von-Laue-Str. 9, 60438 Frankfurt am Main, Germany.
Anal Chem. 2012 Aug 21;84(16):6948-55. doi: 10.1021/ac300372p. Epub 2012 Aug 6.
Although sharing a certain degree of structural uniformity, natural product classes exhibit variable functionalities such as different amino acid or acyl residues. During collision induced dissociation, some natural products exhibit a conserved fragmentation pattern close to the precursor ion. The observed fragments result from a shared set of neutral losses, creating a unique fragmentation pattern, which can be used as a fingerprint for members of these natural product classes. The culture supernatants of 69 strains of the entomopathogenic bacteria Photorhabdus and Xenorhabdus were analyzed by MALDI-MS(2), and a database comprising MS(2) data from each strain was established. This database was scanned for concordant fragmentation patterns of different compounds using a customized software, focusing on relative mass differences of the fragment ions to their precursor ion. A novel group of related natural products comprising 25 different arginine-rich peptides from 16 different strains was identified due to its characteristic neutral loss fragmentation pattern, and the structures of eight compounds were elucidated. Two biosynthesis gene clusters encoding nonribosomal peptide synthetases were identified, emphasizing the possibility to identify a group of structurally and biosynthetically related natural products based on their neutral loss fragmentation pattern.
尽管天然产物类具有一定程度的结构一致性，但它们表现出不同的功能，如不同的氨基酸或酰基残基。在碰撞诱导解离过程中，一些天然产物表现出接近前体离子的保守碎裂模式。观察到的片段来自一组共同的中性丢失，形成独特的碎裂模式，可作为这些天然产物类别的成员的指纹。利用 MALDI-MS(2) 分析了 69 株昆虫病原细菌 Photorhabdus 和 Xenorhabdus 的培养上清液，并建立了包含每个菌株的 MS(2) 数据的数据库。使用定制软件扫描该数据库，以寻找不同化合物的一致碎裂模式，重点是片段离子与其前体离子的相对质量差异。由于其特征性的中性丢失碎裂模式，确定了一组由 16 种不同菌株组成的 25 种不同精氨酸丰富肽的新型相关天然产物，并且还阐明了 8 种化合物的结构。鉴定出两个编码非核糖体肽合酶的生物合成基因簇，强调了基于中性丢失碎裂模式识别一组结构和生物合成相关天然产物的可能性。
