The Effect of Secondary Structures in Peptides and Proteins on Their Chromatographic Separation

The effect of residual secondary structures in peptides and proteins on their separation is considered within the framework of the lattice model of adsorption and chromatography of macromolecules. It is shown that, if the model takes into account secondary structures, such as helices, folds, or crosslinks, the retention volume may change considerably. At the same time, for short peptides with the number of amino-acid units on the order of 20, which result from the enzymatic hydrolysis of proteins, the effect of secondary structures, for example, residual S–S crosslinks, on separation in the model chromatographic experiment is insignificant. For such peptides the main effect on seраration is exerted by their amino-acid composition, and the values of retention volume may be adequately predicted both under the linear chain approximation and in terms of the adsorption additivity model.