膜タンパク質は本当に難しいのか?
ナトリウムチャネルの変性実験を例として
1994 年 34 巻 3 号 p. 101-108
詳細
1994 年 34 巻 3 号 p. 101-108
Denaturation behaviors of sodium channels of squid axon ware studied, using aliphatic alcohols as denaturants. An irreversible suppression of sodium current that could be measured by the intraacellular perfusion was attributable to the denaturation of sodium channels. The denaturation time constant decreased as the alcohol concentration increased. The time constant was prop-ortional to the power of the alcohol concentration with the exponent between 4 and 8. The concentration of alcohol in membrane which denatured half of the sodium channels in 2 hours was about 0.5M irrespective of carbon number of alcohols. The mechanism of the stability of membrane proteins was discussed besed upon these experimental results together with the theoretical calulation of amino acid sequence of bacteriorhodopsin. It was suggested that the folding mechanism of membrane proteins is simpler than soluble proteins and the possibility to predict the molecular structure of membrane proteins was discssed.
