2010R-Current Opinion in Biotechnology-Strong cation exchange (SCX) based analytical methods for the targeted analysis of protein post-translational modifications

Here, we describe how in particular SCX chromatography can be used for the targeted analysis of important post-translational modifications, such as phosphorylation and N-terminal acetylation. Compared to other methods, SCX is less labor-intensive and more robust, and therefore likely more easily adaptable to main-stream research laboratories.

Strong cation exchange (SCX)：强阳离子交换

Figure 1 Typical multidimensional chromatography workflows combining SCX with RP.

In an off-line approach a gradient梯度 of salt (KCl or NaCl) is used for an optimal peptide separation and fractionation. An UV readout紫外线读出 can be used to judge how much of each fraction will be applied for the second RP analysis in order to maintain optimal results. In the on-line version typically a step elution is performed using a more volatile挥发性的 salt such as ammonium acetate乙酸铵 increasing compatibility with the ESI process.