Zimmermann N, Metzger J W, Jung G
Institut für Organische Chemie, Universität Tübingen, Germany.
Eur J Biochem. 1995 Mar 15;228(3):786-97.
The primary structure of the peptide lantibiotic actagardine was determined in (2H3)acetonitrile/H2O by homonuclear two- and three-dimensional NMR spectroscopy as well as 2D 1H(13C) correlation spectra at natural abundance. Actagardine was found to be a tetracyclic 19-residue peptide containing one lanthionine and three overlapping beta-methyllanthionine bridges. Sequential resonance assignment and location of the four thioether rings was accomplished by 2D NOESY, 3D NOESY-TOCSY and gradient-enhanced 1H(13C)-HMBC spectra. The C-terminal thioether bridge was shown to be oxidized to a sulfoxide. The NMR data were additionally confirmed by mass spectrometry and Edman degradation after chemical modification, which allowed sequencing of lanthionine and beta-methyllanthionine residues. Our studies clearly show, that the structure of actagardine as previously published by Kettenring et al. (1990) J. Antibiot. 43, 1082-1088 is not correct.
在（2H3）乙腈/H2O中，通过同核二维和三维核磁共振光谱以及天然丰度下的二维1H(13C)相关光谱，确定了羊毛硫抗生素阿他加定的一级结构。发现阿他加定是一种含有一个羊毛硫氨酸和三个重叠的β-甲基羊毛硫氨酸桥的四环19残基肽。通过二维核Overhauser效应光谱（NOESY）、三维NOESY-全相关光谱（TOCSY）和梯度增强的1H(13C)-异核多键相关光谱（HMBC）完成了四个硫醚环的顺序共振归属和定位。结果表明，C端硫醚桥被氧化为亚砜。化学修饰后的核磁共振数据通过质谱和埃德曼降解进一步得到证实，这使得能够对羊毛硫氨酸和β-甲基羊毛硫氨酸残基进行测序。我们的研究清楚地表明，Kettenring等人（1990年，《抗生素杂志》43卷，1082 - 1088页）之前发表的阿他加定结构是不正确的。
