Abstract:

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.

Key words: Electro spray ionization-mass spectroscopy(ESI-MS), N-Phosphoryl dopamine, Lysozyme, Non-covalent interaction