Screening of antagonists based on induced dissociation of a calmodulin–melittin interaction entrapped in a sol–gel derived matrix

Sol–gel derived materials offer a unique advantage for the development of sensing and screening platforms in that they allow for the entrapment of multiple species within a confined space. In this work, we show that it is possible to entrap an intact protein–peptide interaction, consisting of bovine calmodulin (bCaM) and melittin, into a sol–gel derived silicate material. Fluorescence emission data demonstrate that the entrapped complex behaves similarly to the complex in solution, and can undergo reversible dissociation upon introduction of the denaturant guanidine hydrochloride. Screening of antagonists of the bCaM–melittin complex was accomplished based on induced dissociation of the entrapped complex, which was followed by measuring the loss of sensitization of Tb(III) luminescence originating from energy transfer from the Trp of melittin to Tb(III) bound in the loops of bCaM. This study shows that entrapped protein–peptide complexes can be used as targets for drug screening or for fluorescence-based biosensing.