A study of Src SH2 domain protein–phosphopeptide binding interactions by electrospray ionization mass spectrometry
- JA Loo, P Hu, P McConnell, WT Mueller, TK Sawyer, V Thanabal
- J Am Soc Mass Spectrom
According to previous literature, pYEEI and AcpYEEI also have high affinity with the SH2 domain specifically. However, up to now, few researches pay attention to the interaction difference between these two phosphopeptides which is caused by the N-terminal acetylation. In this paper, the competitive interaction between the SH2 domain and phosphopeptides (AcpYEEI and pYEEI) was investigated by native ESI ion trap mass spectrometry combined theoretical calculations. It was found that N-terminal acetylation of pYEEI strengthens the interaction with the SH2 domain. Through theoretical calculations, the binding affinity, K a of AcpYEEI is approximately 91 times larger than K a of pYEEI. The possible enhancement mechanism was proposed here.