[Selective transport of Li+ and Na+ through lipid bilayers by nanhumycin].
Nanhumycin, a new polyether antibiotic, has potent growth inhibitory effect on hay bacillus and antagonistic activity against chicken coccidiosis. Previous experiments on nerve-muscle preparations have shown that all the effects of nanhumycin on biological membrane could be correlated with its ability to act as a Na+ carrier. In this paper, the effects of nanhumycin on the permeability of the lipid bilayers were characterized and the main results were as follows: Nanhumycin caused a concentration-dependent increase in membrane conductance (Gm) of the lipid bilayers. By measuring the reversal potential in an asymmetrical solution system, it was demonstrated that the changes of Gm were attributed to an increase in permeability of the lipid bilayers to cations (PLi/PNa = 0.02), especially to Li+ and Na+. The PLi:PNa:PK = 4.55:1.00:0.03. These results suggests that nanhumycin is a cation carrier with high permeability for Li+ and Na+.
Henan Medical University, Zhengzhou.
J J
JJ
Cui
S B
SB
Tang
Y L
YL
Shi
W P
WP
Wang
D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D005663:Furans / Q000494:pharmacology*; D017136:Ion Transport / Q000187:drug effects; D008051:Lipid Bilayers; D008094:Lithium / Q000493:pharmacokinetics*; D008954:Models, Biological; D010539:Permeability; D011714:Pyrans / Q000494:pharmacology*; D012964:Sodium / Q000493:pharmacokinetics*
D000900:Anti-Bacterial Agents; D005663:Furans; D008051:Lipid Bilayers; D011714:Pyrans; C086505:nanhumycin; D008094:Lithium; D012964:Sodium