Isolation and characterization of a fraction from brain that inhibits 1,4‐[3H]dihydropyridine binding and L‐type calcium channel current

Publisher Website
Google Scholar
Abstract
Bovine brain was subjected to acid extraction and several purification steps. A fraction from brain that eluted from C18 reverse-phase columns at 30–35% acetonitrile inhibited [3H]nitrendipine binding to cardiac membranes. Further purification of this fraction on a sizing column in the presence of 40% acetonitrile yielded a low molecular mass fraction (< 1 kDa) that produced a time- and voltage-dependent inhibition of L-type (but not T-type) Ca2+-channel current in GH3 cells. The results suggest that this fraction contains an endogenous substance that binds directly to slowly-inactivating Ca2+ channels and thereby inhibits current flow.