Home
Resources
Publications
Reconstituted Voltage-Sensitive Sodium Channels From Eel Electroplax: Activation of Permeability by Quaternary Lidocaine, N-bromoacetamide, and N-bromosuccinimide

Reconstituted Voltage-Sensitive Sodium Channels From Eel Electroplax: Activation of Permeability by Quaternary Lidocaine, N-bromoacetamide, and N-bromosuccinimide

E C Cooper, W S Agnew

J Membr Biol. 1989 Nov;111(3):253-64.

PMID: 2557451

Abstract:

We have investigated the ion permeability properties of sodium channels purified from eel electroplax and reconstituted into liposomes. Under the influence of a depolarizing diffusion potential, these channels appear capable of occasional spontaneous openings. Fluxes which result from these openings are sodium selective and blocked (from opposite sides of the membrane) by tetrodotoxin (TTX) and moderate concentrations of the lidocaine analogue QX-314. Low concentrations of QX-314 paradoxically enhance this channel-mediated flux. N-bromoacetamide (NBA) and N-bromosuccinimide (NBS), reagents which remove inactivation gating in physiological preparations, transiently stimulate the sodium permeability of inside-out facing channels to high levels. The rise and subsequent fall of permeability appear to result from consecutive covalent modifications of the protein. Titration of the protein with the more reactive NBS can be used to produce stable, chronically active forms of the protein. Low concentrations of QX-314 produce a net facilitation of channel activation by NBA, while higher concentrations produce block of conductance. This suggests that rates of modifications by NBA which lead to the activation of permeability are influenced by conformational changes induced by QX-314 binding.

Chemicals Related in the Paper:

Catalog Number	Product Name	Structure	CAS Number	Price
AP79152	N-Bromoacetamide		79-15-2	Price

As a specialist in analytical chemical Products, Alfa Chemistry offers consumers a wealth of raw materials and a full range of technologies and services.

QUICK LINKS

HEADQUARTERS

Tel:

Fax:

Email: