Diversity of monomeric prolamins in triticale cultivars determined by capillary zone electrophoresis

Capillary zone electrophoretic (CZE) analysis of monomeric prolamins (wheat gliadins and rye secalins) covered 28 hexaploid triticale ( Triticosecale x Wittm.) cultivars. The ethanol-soluble proteins were separated on an uncoated fused-silica capillary using the isoelectric 60 mM iminodiacetic (IDA) buffer in conjunction with 20% (v/v) acetonitrile and 0.075% (w/v) polyvinylpyrrolidone (PVP). For each separation, dynamic coating of the capillary wall with a buffer containing 0.1 M IDA and 0.05% (w/v) hydroxypropylmethylcellulose (HPMC) was performed. Separations of prolamins provided very good resolution and high reproducibility (<0.8% RSD). Prolamin profiles of all analyzed cultivars showed both qualitative and quantitative differences, including number of peaks, presence or absence of peaks, and area of peaks. The number of prolamin peaks detected in particular triticale cultivars varied from 22 to 28; in total, 56 components were distinguished. The CZE electropherograms of prolamins showed five main groups of protein peaks, in order of mobility alpha-prolamins, beta-prolamins, gamma-prolamins, omega1-prolamins, and omega2-prolamins, with migration times of 6.8-7.7, 7.8-10.4, 10.5-12.2, 12.3-17.4, and 17.5-25.6 min, respectively. Triticale seeds in comparison with wheat contained fewer alpha-prolamins and higher quantity of omega-prolamins. Hierarchical clustering of the investigated cultivars was based on Bhattacharyya distances calculated from the CZE data. The cultivars grouped in four main clusters. The obtained CZE results were compared with A-PAGE data.