title: Generation of functional ion-channel tools by E3 targeting.
abstract: Here we describe a strategy for generating ion-channel inhibitors. It takes advantage of antibody specificity combined with a pattern recognition approach that targets the third extracellular region (E3) of a channel. To test the concept, we first focused on TRPC5, a member of the transient receptor potential (TRP) calcium channel family, the study of which has been hindered by poor pharmacological tools. Extracellular application of E3-targeted anti-TRPC5 antibody led to a specific TRPC5 inhibitor, enabling TRPC5 to be distinguished from its closest family members, and TRPC5 function to be explored in a relatively intractable physiological system. E3 targeting was further applied to voltage-gated sodium channels, leading to discovery of a subtype-specific inhibitor of Na(V)1.5. These examples illustrate the potential power of E3 targeting as a systematic method for producing gene-type specific ion-channel inhibitors for use in routine assays on cells or tissues from a range of species and having therapeutic potential.
authors.affiliation: Membrane and Systems Biology Research Institute, University of Leeds, Leeds, LS2 9JT, UK.
authors.forename: Shang-Zhong
authors.initials: SZ
authors.lastname: Xu
authors.forename: Fanning
authors.initials: F
authors.lastname: Zeng
authors.forename: Ming
authors.initials: M
authors.lastname: Lei
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.forename: Bin
authors.initials: B
authors.lastname: Gao
authors.forename: Chenliang
authors.initials: C
authors.lastname: Xiong
authors.forename: Asipu
authors.initials: A
authors.lastname: Sivaprasadarao
authors.forename: David J
authors.initials: DJ
authors.lastname: Beech
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D001665:Binding Sites; D016503:Drug Delivery Systems / Q000379:methods*; D015640:Ion Channel Gating / Q000187:drug effects* / Q000502:physiology*; D007473:Ion Channels / Q000187:drug effects / Q000502:physiology; D011485:Protein Binding; D015202:Protein Engineering / Q000379:methods*; D050052:TRPC Cation Channels / Q000187:drug effects* / Q000502:physiology*
chemical_list: D000911:Antibodies, Monoclonal; D007473:Ion Channels; D050052:TRPC Cation Channels; C491780:TRPC5 protein, human