RNA aptamers that specifically bind to a K Ras-derived farnesylated peptide.
RNA aptamers were selected against an affinity column containing a farnesylated peptide modeled after the carboxyl terminus of K ras, the major 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 consensus sequences--GGGUGGG and GGGAGG. Quantitative fluorescence binding studies on two of the high-affinity aptamers, showed a binding affinities of 139 nM and 0.93 microM, respectively for the farnesylated peptide. Binding to the nonfarnesylated peptide was at least 10-fold weaker, showing that the aptamers can recognize the hydrophobic farnesyl moiety. High affinity aptamers could be useful in specifically interfering with oncogenic ras function in particular, and G proteins in general.
Gilbert
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Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA.
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Wathen
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Rando
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D001483:Base Sequence; D002846:Chromatography, Affinity; D007700:Kinetics; D008969:Molecular Sequence Data; D017368:Protein Prenylation; D012313:RNA / Q000378:metabolism*; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity; D018631:ras Proteins / Q000378:metabolism*
D012313:RNA; D018631:ras Proteins