DIBMA Glucosamine, HEPES

One challenge when working with traditional DIBMA is its sensitivity to the presence of ions inside the buffer / media. The reason for this is DIBMAs own charge that lets it interact with these ions. This leads to precipitation of DIBMA and therefore loss of its function. To overcome this issue we modified DIBMA to have a reduced charge to drastically reduce the affinity to the ions. This was achieved by adding Glucosamine or an amino-functionalized diol to DIBMA (see figure 1). This modified DIBMA can be used for experiments for which the presence of ions is crucial for their success.

As figure 2 indicates, the increased tolerance of Ca²⁺ is necessary. Normally, DIBMA starts to precipitate in Ca²⁺ holding buffers at a concentration of around 25 mM. Using DIBMA-Glycerol this tolerance increases to 50 mM. There is no precipitate visible at the bottom of the tube. In comparison normal DIBMA shows a visible precipitate at 25 mM. In terms of Mg²⁺ tolerance, traditional and Glycerol DIBMAs both show a high tolerance above 50 mM.