Ba. Gilbert et al., RNA APTAMERS THAT SPECIFICALLY BIND TO A K-RAS-DERIVED FARNESYLATED PEPTIDE, Bioorganic & medicinal chemistry, 5(6), 1997, pp. 1115-1122
RNA aptamers were selected against an affinity column containing a far
nesylated peptide modeled after the carboxyl terminus of K ras, the ma
jor oncogenic form of this small G protein family. After 10-rounds of
selection, 25% of the RNA applied to the column could be specifically
eluted. Sequence analysis of the binding RNA aptamers revealed two con
sensus sequences-GGGUGGG and GGGAGG. Quantitative fluorescence binding
studies on two of the high-affinity aptamers, showed a binding affini
ties of 139 nM and 0.93 mu M, respectively for the farnesylated peptid
e. Binding to the nonfarnesylated peptide was at least 10-fold weaker,
showing that the aptamers can recognize the hydrophobic farnesyl moie
ty. High affinity aptamers could be useful in specifically interfering
with oncogenic ras function in particular, and G proteins in general.
(C) 1997 Elsevier Science Ltd.