The contribution of the three-dimensional structures of one heptapeptide (PQPQPFP) sequence and one pentapeptide (PQQPY) repeat sequence of alpha/beta-gliadins, one heptapeptide (PQQPFPQ) repeat sequence of gamma-gliadins, two heptapeptide (PQQPPFS and QQQQPVL) repeat motifs of low-molecular-weight (LMW) subunits and a tetrapeptide sequence in polyQ region of S-rich prolamins to their conformations are investigated by using the recently developed multicanonical simulation procedure. Ramachandran plots were prepared and analysed to predict the relative occurrence probabilities of gamma-tutn, gamma-turn, and helical structures. The probability of inverse 7-turn was generally higher than that of beta-turns in all sequences investigated. Occurrence probability of helical structure in the repetitive domain of gliadins was low. Structural predictions of QQQQPVL sequence of LMW-glutenin subunits and QQQQ sequence in the polyQ region of S-rich prolamins indicate the presence of helical structures with the probability of >20%. The probability of helical structure significantly decreased around 100 degrees C.