title: Molecular modeling of various peptide sequences of gliadins and low-molecular-weight glutenin subunits.
abstract: 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.
mesh_terms: D000595:Amino Acid Sequence; D005903:Gliadin / Q000737:chemistry*; D005983:Glutens / Q000031:analogs & derivatives* / Q000737:chemistry*; D008958:Models, Molecular; D015394:Molecular Structure; D008970:Molecular Weight; D017433:Protein Structure, Secondary; D040681:Structural Homology, Protein
chemical_list: D005983:Glutens; D005903:Gliadin; C037302:glutenin