植物甜蛋白马宾灵(Mabinlin Ⅱ)的二级结构及其B细胞抗原表位预测

马宾灵(MabinlinⅡ)是中国所特有的植物甜蛋白,在目前已知的7种植物甜蛋白中具有最佳的热稳定性,将其作为新型甜味剂有着广阔的市场前景。本研究以马宾灵的氨基酸序列为基础,采用Garnier-Robson方法和Chou-Fasman方法预测马宾灵的二级结构,采用Karplus-Schulz方法预测马宾灵的蛋白质骨架区柔韧性,采用Kyte-Doolittle方法预测马宾灵的蛋白质疏水性,采用Emini方法预测马宾灵的蛋白质表面可能性,采用Jameson-Wolf方法预测马宾灵的B细胞抗原表位。分析结果表明,马宾灵的A链多形成转角和无规则卷曲结构,A链的N端27～30区段形成较柔软的蛋白质骨架结构,A链的N端4～6、7～9、10～11、12～14、20～22、23～26和30～33区段为抗原位点的可能性较大;马宾灵的B链多形成β折叠和转角结构,B链的N端0～7、9～13、28～29、33～34、40～45、53～54和55～57区段为抗原位点的可能性较大。本研究以生物信息学手段分析预测马宾灵的二级结构及其B细胞抗原表位,为设计马宾灵多克隆抗体以检测马宾灵在不同生物反应器中的表达研究提供参考数据。

Prediction of the Secondary Structure and B Cell Epitopes of the Plant Sweet Protein MabinlinⅡ

Mabinlin Ⅱis the unique plant sweet protein in China,and it has the best thermal stability of the seven plant sweet proteins which have been known today.MabinlinⅡmay has a promising market to be a new food sweetener.Based on the amino acid sequence of MabinlinⅡ,the secondary structure of it was predicted with the methods of Garnier-Robson and Chou-Fasman,and the flexiblity of the backbone structure of it was predicted with the Karplus-Schulz method,and the hydrophobicity of it was predicted with the Kyte-Doolittle method,and the possibility of surface area of it was predicted with the Emini method,the B-cell epitopes of it was predicted with the Jameson-Wolf method.The results show that the structure of the A-chain of MabinlinⅡmostly consists of turns and random coils,and the 27~30 amino acid section from the N-terminal become a more flexible skeleton structure,while the 4~6,7~9,10~11,12~14,20~22,23~26 and 30~33 amino acid sections from the N-terminal are probably the key antigenic sites.The structure of the B-chain of MabinlinⅡmostly consists of β-sheet and turn regions,and the 0~7,9~13,28~29,33~34,40~45,53~54 and 55~57 amino acid sections from the N-terminal may be the key antigenic sites.The bioinformatics analysis of this protein may provide a reference for the design of polyclonal antibody against the MabinlinⅡ which would be used to detect the expression of MabinlinⅡin different bioreactors.