Inhibition of Ca2+ and K+ currents by "antifreeze" proteins.
For the last two decades, the research on fish "antifreeze" proteins has focused exclusively on their ability to depress noncolligatively blood plasma freezing points, presumably by binding to ice crystals. We report evidence that antifreeze polypeptides from the winter flounder (Pseudopleuronectes americanus) have another special property, the ability to block ion channels. In experiments with porcine granulosa cells we show, using the patch-clamp technique in the whole cell configuration, that these proteins suppress effectively calcium and potassium currents. The results of dose-response studies indicate a protein-protein interaction mechanism.
Rubinsky
B
B
Department of Mechanical Engineering, University of California, Berkeley 94720.
Mattioli
M
M
Arav
A
A
Barboni
B
B
Fletcher
G L
GL
D000818:Animals; D021301:Antifreeze Proteins; D015220:Calcium Channels / Q000187:drug effects / Q000502:physiology*; D005260:Female; D005615:Freezing; D006023:Glycoproteins / Q000494:pharmacology*; D006107:Granulosa Cells / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D015221:Potassium Channels / Q000187:drug effects / Q000502:physiology*; D013552:Swine
D021301:Antifreeze Proteins; D015220:Calcium Channels; D006023:Glycoproteins; D015221:Potassium Channels