The effect of Hofmeister anions on water network near protein surface
2017 119th KCS Meeting
We have focused on the water in protein interface using MD simulation. Go further we investigated the change of water network at interface under the ionic condition to understand the ion effect near protein surface. The H-bond number of water is the criteria which represents water network, already there are many researches about H-bond number along distance from hydrophobic surface such as protein and graphite. The collapse of water network is observed near protein surface from our results through the decrease of H-bond number. Under ionic condition, H-bond decrease patterns are revealed differently along the Hofmeister anion series which is related with solubility of protein near protein surface while there are no specific ion effects over 5 Å region. This result has relation with ion distribution. Chaotropic anions showed higher preference near protein surface than kosmotropic anions. Additionally, we investigated the number distribution and orientation distribution of each configuration of water to confirm preferential orientation at organic phase/water interface. Our results showed that the water has mainly random distribution, but slightly there are preferential configuration for straddle structure at protein/water interface.