The need for biochemical quantities of nonmuscle actin has been increa
sed by observations that actin isoform composition of a cell influence
s the cell's motile and structural properties. In addition, the number
of actin binding proteins that exhibit different binding interactions
with beta- and gamma-actin compared to oi-actin from skeletal muscle
is growing. We report a procedure designed to purify actin from nonmus
cle tissues employing extraction of monomeric actin from tissues with
high concentrations of Tris, chromatography on DE-53 cellulose, and af
finity chromatography of DNase I-agarose. The preparation is easy to p
erform and yields quantities of nonmuscle actin sufficient for biochem
ical and cell biological assays. Actin from bovine erythrocytes and fr
om brains of adult and embryonic chickens was obtained using this meth
od. which can be readily used with other sources of tissue. Coomassie-
Blue-stained SDS gels of the purified actin show no contaminants; capp
ing protein, a common contaminant of actin preparations, is absent by
immunoblotting. This method for purifying nonmuscle actin will be usef
ul to investigate functional differences in the biology of actin isofo
rms or their regulating proteins. (C) 1998 Wiley-Liss, Inc.