title: Clicked bis-PEG-peptide conjugates for studying calmodulin-Kv7.2 channel binding.
abstract: The recombinant Kv7.2 calmodulin (CaM) binding site (Q2AB CaMBD) shows a high tendency to aggregate, thus complicating biochemical and structural studies. To facilitate these studies we have conceived bis-PEG-peptide CaMBD-mimetics linking helices A and B in single, easy to handle molecules. Short PEG chains were selected as spacers between the two peptide molecules, and a Cu(i)-catalyzed cycloaddition (CuAAC) protocol was used to assemble the final bis-PEG-peptide conjugate, by the convenient functionalization of PEG arms with azide and alkyne groups. The resulting conjugates, with a certain helical character in TFE solutions (CD), showed nanomolar affinity in a fluorescence CaM binding in vitro assay, higher than just the sum of the precursor PEG-peptide affinities, thus validating our design. The approach to these first described examples of Kv7.2 CaMBD-mimetics could pave the way to chimeric conjugates merging helices A and B from different Kv7 subunits.
authors.affiliation: Instituto de Química-Médica (IQM-CSIC), Juan de la Cierva 3, 28006 Madrid, Spain. rosario.gonzalezmuniz@iqm.csic.es.
authors.forename: M Angeles
authors.initials: MA
authors.lastname: Bonache
authors.forename: Alessandro
authors.initials: A
authors.lastname: Alaimo
authors.forename: Covadonga
authors.initials: C
authors.lastname: Malo
authors.forename: Oscar
authors.initials: O
authors.lastname: Millet
authors.forename: Alvaro
authors.initials: A
authors.lastname: Villarroel
authors.forename: Rosario
authors.initials: R
authors.lastname: González-Muñiz
mesh_terms: D001665:Binding Sites; D002147:Calmodulin / Q000737:chemistry*; D057930:Click Chemistry; D008968:Molecular Conformation; D010455:Peptides / Q000737:chemistry*; D011092:Polyethylene Glycols / Q000737:chemistry*
chemical_list: D002147:Calmodulin; D010455:Peptides; D011092:Polyethylene Glycols