title: Identification and Localization of Gold Nanoparticles in Potassium Ion Pores: Implications for Kir Blockade.
abstract: BACKGROUND
  In our previous study, we found that negatively charged gold nanoparticles with spermidine have the potential of blocking inwardly rectifying potassium channels (Kir), both at the cellular and the tissue level.
  
  
  METHODS
  For the purpose of the present study, we purified the cytoplasmic domain of the Kir 3.1 receptor from Escherichia coli. Using single particles with surface coating by transmission electron microscopy, we identified the gold nanoparticles at the cytoplasmic side of the human Kir channel.
  
  
  RESULTS
  Energy-dispersive X-ray spectroscopy showed the presence of the gold deposits in the cytoplasmic domain of the Kir receptor.
  
  
  CONCLUSIONS
  In conclusion, we could identify undecagold in the ion pore of the Kir3.1 channel in order to clarify its direct blocking effect in the Kir ion pore by undecagold.
authors.affiliation: Department of Internal Medicine, Soon Chun Hyang University Bucheon Hospital, Bucheon, Kyunggi-do, Republic of Korea. nanomedicin6@gmail.com.
authors.forename: Chur
authors.initials: C
authors.lastname: Chin
authors.affiliation: Center for Core Research Facilities, DGIST, Daegu, 711-873, Republic of Korea.
authors.forename: Yu Shin
authors.initials: YS
authors.lastname: Park
keywords: CryoEM; Cytoplasmic domain; Kir3.1; STEM