Pesavento James J, Mizzen Craig A, Kelleher Neil L
Center for Biophysics and Computational Biology, Department of Cell and Developmental Biology, Institute for Genomic Biology (IGB), University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
Anal Chem. 2006 Jul 1;78(13):4271-80. doi: 10.1021/ac0600050.
Here we show that fragment ion abundances from dissociation of ions created from mixtures of multiply modified histone H4 (11 kDa) or of N-terminal synthetic peptides (2 kDa) correspond to their respective intact ion abundances measured by Fourier transform mass spectrometry. Isomeric mixtures of modified forms of the same protein are resolved and quantitated with a precision of </=5% using the relative ratios of their fragment ions, with intact protein ions created by electrospray greatly easing many of the systematic biases that more strongly affect small peptides (e.g., differences in ionization efficiency and ion m/z values). The ion fragmentation methods validated here are directly extensible to intact human proteins to derive quantitative information on the highly related and often isomeric protein forms created by combinatorial arrays of posttranslational modifications.
在此我们表明，由多重修饰的组蛋白H4（11 kDa）混合物或N端合成肽（2 kDa）产生的离子解离所得到的碎片离子丰度，与通过傅里叶变换质谱法测量的各自完整离子丰度相对应。使用相同蛋白质修饰形式的同分异构体混合物的碎片离子相对比率，可分辨并定量这些混合物，其精度≤5%，通过电喷雾产生的完整蛋白质离子极大地减轻了许多对小肽影响更强的系统偏差（例如，电离效率和离子m/z值的差异）。此处验证的离子碎裂方法可直接扩展至完整的人类蛋白质，以获取有关由翻译后修饰组合阵列产生的高度相关且通常为同分异构体的蛋白质形式的定量信息。
