N-磷酰化多巴胺与溶菌酶相互作用的ESI-MS研究

Interaction Between N-Phosphoryl Dopamines and Lysozyme by ESI-MS

采用电喷雾离子肼-质谱(ESI-MS)研究了一系列结构具有可比性的N-磷酰化多巴胺与溶菌酶的非共价相互作用,比较了磷上不同取代基对相互作用的影响.结果表明,磷上的烷氧取代基上烷基碳原子的个数及排列顺序对二者相互作用有较大影响;取代基上碳链越长,溶液中溶菌酶的构象越趋于收缩,二者之间越容易形成带低电荷和高质核比的复合物,且其稳定性也随着取代基的增长而增强;当取代基碳原子数相同时,直链取代的磷酰化多巴胺与溶菌酶形成的复合物比支链取代的底物与溶菌酶形成的复合物稳定.

The non-covalent interaction between a series of N-phosphoryl dopamines synthesized in our pre-vious work and lysozyme was studied by electro spray ionization-mass spectroscopy（ESI-MS）.The effects of different groups of P on N-phosphoryl dopamine were compared.The results showed that the length of alkyl group of alkoxyl group on P was very important for the interaction under ESI-MS conditions.N-phosphoryl dopamines with longer carbon chains could contract the protein configuration in solution and were inclined to form complexes with lysozyme that have a lower charge and higher m/z and more stability.The sequence of carbon chain also had an obvious effect on the stability of the complex.Straight chain was more beneficial for the stability than branched chain when the number of carbon was equal.Isomers showed a different effect on the protein configuration in solution when alkyl group of alkoxyl group on P was propyl or isopropyl group.The maximal stoichiometric proportion of the complexes of N-phosphoryl dopamines and lysozyme is 5∶ 1.The results are valuable for the design of new active dopamine molecules.