关键词: 小麦, 低分子量谷蛋白亚基, 二级结构

Abstract: In order to study relationship between the secondary structure and functions of low-molecular-weight glutenin subunits, the secondary structures of the putative amino acid sequences from 19 LMW-GS gene known whole coding region and chromosomal location were predicted by softwares of predicting protein in internet. The results show that, in the secondary structure of LMW-GS, coil content is the highest, to 69.51%. In comparison with β-sheet at 1.33%, α-helix at 28.97% is outstandingly high, implying that LMW-GS belongs to α-class protein according to the protein structural class. The signal peptide consists of abundant α-helix and little coil. Both the N-terminal region and the repetitive region are occupied by coil. The C-terminal region is rich in α-helix and coil, besides little β-sheet. Meanwhile two intermolecular disulfide bonds are situated in coil, while the other six intra-molecular disulfide bonds are situated in or close to the α-helix. Diagram representing the secondary structures of typical LMW-GS is drawn based on types in combination with both their frequencies and distributions of the predicted protein secondary structures. The result might not only prove classic theories, like primary structure determining the higher structures of protein and the basic function of synthesized proteins into proper cytoplasm, but also explain the structural basis of the hardness, enrichment and polymerized of multi-peptides chains with HMW-GS influencing the technological properties of wheat flour.

Key words: wheat, low molecular weight glutenin, secondary structure