Colchicine binding Activity in Extracts of Higher Plants

Abstract

The binding of [³H] to soluble components in extracts from a variety of higher plant tissues has been assayed by gel filtration and by the filter disc method. The binding activity, although present only to a low degree and requiring at least concentration by ammonium sulphate precipitation before assay, showed some of the characteristics of tubulin, including enhancement by the presence of vinblastine. Practical difficulties involved in investigating, and in interpreting the significance of the colchicine-binding activity of higher plants arise both from the inhibiting effect on binding of the plant extracts themselves, and from the fact that lumicolehicine was also bound by the preparations under certain conditions.