Determining the minimal amount of DMSO necessary to stabilize the Angiomotin lipid binding domain

Angiomotins (Amots) are a family of adaptor proteins with important roles in cell growth, migration, and proliferation. The Amot coiled-coil homology (ACCH) domain, has a high affinity for non-phosphorylated phosphatidylinositol and mono-phosphorylated phosphatidylinositol. This provides specificity in the membrane association. This membrane specificity is linked with the targeting and recycling of the membrane protein in order to maintain normal cell phenotypes and function. Therefore, we endeavored to understand the protein function by studying the atomic structure of the protein. Our laboratory looked to determine the structure using nuclear magnetic resonance (NMR), which requires higher protein concentrations than those possible in our current buffered solutions. Based on literature reported on other proteins, DMSO can be used as a stabilizing agent up to 33-70% DMSO. Higher concentrations have led DMSO to become a denaturing agent. Therefore, this work shows our preliminary findings for the minimal amount of dimethyl sulfoxide (DMSO) needed to stabilize the domain at higher concentrations without disrupting its native structure. To that end, we determined DMSO related changes in protein structure seen as shifts in the melting temperature that is determined by dynamic scanning fluorescence measurements. As a result, we found that the ACCH domain is denatured in solutions >10% DMSO.