Structure and heterogeneity of gliadin: a hydrodynamic evaluation

A study of the heterogeneity and conformation in solution [in 70% (v/v) aq. ethanol] of gliadin proteins from wheat was undertaken based upon sedimentation velocity in the analytical ultracentrifuge, analysis of the distribution coefficients and ellipsoidal axial ratios assuming quasi-rigid particles, allowing for a range of plausible time-averaged hydration values. All classical fractions (alpha, gamma, omega(slow), omega(fast)) show three clearly resolved components. Based on the weight-average sedimentation coefficient for each fraction and a weight-average molecular weight from sedimentation equilibrium and/or cDNA sequence analysis, all the proteins are extended molecules with axial ratios ranging from ~10 to 30 with alpha appearing the most extended and gamma the least.