Structural Changes of Legumin from Faba Beans (Vicia faba L.) by Succinylation

The effect of progressive succinylation upon the conformation of faba bean legumin has been studied using chemical analysis, viscometry, analytical ultracentrifugation, UV and fluorescence spectroscopy, and differential scanning calorimetry (DSC). The protein dissociates gradually into 3 S subunits forming a 7 S intermediate. DSC measurements revealed a continuous loosening of the spacial structure with increasing degree of succinylation. Viscometric and spectroscopic studies indicate the presence of a particular conformational state at 60−80% succinylation, whereas a largely expanded structure was shown to exist in exhaustively succinylated legumin due to a cumulative effect of N- and O-succinylation. Keywords: Legumin; faba bean protein; succinylation; conformational changes