N-磷酰化肽酯及小肽与溶菌酶相互作用的ESI-MS研究

用ESI-MS研究了一系列结构具有可比性的N-磷酰化肽酯及小肽和溶菌酶的非共价相互作用, 比较了磷酰化肽酯及小肽分子中的不同基团对相互作用的影响. 结果表明—OH对其与溶菌酶的相互作用有较大贡献; 芳香环由于位阻原因, 对相互作用有促进和阻碍双重效应; 当—OH与芳香环相连时会发生协同效应, 可使相互作用显著增强. 磷酰化肽酯及小肽的体积大小、空间位阻对相互作用亦有显著影响. 磷酰化二肽中氨基酸残基的构型、顺序、碳链长短的变化(增加1～2个C)对其与蛋白溶菌酶之间的相互作用在质谱中没有表现出影响. 分子结构较为伸展、分子柔顺性好、空间位阻较小的磷酰化小肽更容易使蛋白在溶液中的构象趋于收缩, 而构象较为收缩的蛋白分子更易结合空间位阻较小的磷酰化小肽分子.

Study on the Interaction between N-Phosphoryl Dipeptides (or Methyl Esters) and Lysozyme by ESI-MS

The non-covalent interaction between a series of N-phosphoryl dipeptides (or methyl esters) and lysozyme was studied by using ESI-MS. The effects of different groups of N-phosphoryl dipeptides (or methyl esters) were compared. The results show that -OH is very important for the interaction, and the aromatic ring has double functions on the interaction because of its steric hindrance. The linked -OH and aromatic ring showed synergistic reaction and enhanced their interaction. Moreover, the size of the molecule and steric hindrance showed obvious effects on the interaction, while the configuration, sequence and length of carbon chains (increasing 1～2 C) of amino acid residue in the phosphoryl oligopeptides showed little effects on the interaction under ESI-MS conditions. Phosphoryl oligopeptides having extended construction, increasing molecular flexibility and smaller spatial hindrance could contract the protein configuration in solution, and the contractive protein molecule integrated with the smaller phosphoryl oligopeptide molecules more easily.