Bythell Benjamin J, Erlekam Undine, Paizs Béla, Maître Philippe
Department of Molecular Biophysics, German Cancer Research Center, Im Neuenheimer Feld 580, Heidelberg, Germany.
Chemphyschem. 2009 Apr 14;10(6):883-5. doi: 10.1002/cphc.200800804.
Most proteins in proteomics are identified from tandem mass spectra of doubly protonated tryptic peptides. Statistical studies indicate that these spectra fall into two distinct classes. IR spectroscopy experiments and DFT calculations performed on model b(2) ions show that peptides producing Class I spectra form protonated oxazolone ions (see figure) and not protonated diketopiperazines as proposed elsewhere.
蛋白质组学中的大多数蛋白质是从双质子化胰蛋白酶肽段的串联质谱中鉴定出来的。统计研究表明，这些质谱可分为两个不同的类别。对模型b(2)离子进行的红外光谱实验和密度泛函理论计算表明，产生I类质谱的肽段会形成质子化恶唑酮离子（见图），而不是如其他地方所提出的质子化二酮哌嗪。
