University of Massachusetts Medical School Faculty Publications


Chemical derivatization and purification of peptide-toxins for probing ion channel complexes

UMMS Affiliation

Department of Biochemistry and Molecular Pharmacology

Publication Date


Document Type

Book Chapter


Laboratory and Basic Science Research | Molecular Biology | Neuroscience and Neurobiology


Ion channels function as multi-protein complexes made up of ion-conducting alpha-subunits and regulatory beta-subunits. To detect, identify, and quantitate the regulatory beta-subunits in functioning K(+) channel complexes, we have chemically derivatized peptide-toxins that specifically react with strategically placed cysteine residues in the channel complex. Two protein labeling approaches have been developed to derivatize the peptide-toxin, charybdotoxin, with hydrophilic and hydrophobic bismaleimides, and other molecular probes. Using these cysteine-reactive peptide-toxins, we have specifically targeted KCNQ1-KCNE1 K(+) channel complexes expressed in both Xenopus oocytes and mammalian cells. The modular design of the reagents should permit this approach to be applied to the many ion channel complexes involved in electrical excitability as well as salt and water homoeostasis.

DOI of Published Version



Methods Mol Biol. 2013;995:19-30. doi: 10.1007/978-1-62703-345-9_2. Link to article on publisher's site

Related Resources

Link to Article in PubMed

Journal/Book/Conference Title

Methods in molecular biology (Clifton, N.J.)

PubMed ID