Single Channel Behavior of a Purified Epithelial Na(+) Channel Subunit that Binds Amiloride
Abstract
The apical membrane of high electrical resistance epithelia, which is selectively permeable to Na(+), plays an essential role in the maintenance of salt balance. Na(+) entry from the apical fluid into the cells is mediated by amiloride-blockable Na(+)-specific channels. The channel protein purified from both amphibian and mammalian sources, is composed of several subunits, only one of which, the 150-kDa polypeptide, specifically binds the Na(+) transport inhibitor amiloride. The goal of the present study was to investigate whether the isolated amiloride-binding subunit of the channel could conduct Na(+). The patch-clamp techniques was used to study the 150-kDa polypeptide, specifically binds the Na(+) transport inhibitor amiloride. The goal of the present study was to investigate whether the isolated amiloride-binding subunit of the channel could conduct Na(+). The patch-clamp technique was used to study the 150-kDa polypeptide incorporated into a lipid bilayer formed on the tip of a glass pipette. Unitary conductance jumps averaged 4.8 pS at 100 mM Na2HPO4.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1992
- Accession Number
- ADA259376
Entities
People
- Maurice Abramow
- Richard Fisher
- Sarah Sariban-sohraby
Organizations
- Walter Reed Army Institute of Research