Isolation and characterization of the histones from cycad pollen

Abstract

Sequence studies of calf and pea histone F3 and F2al have revealed that these histones are evolutionarily very stable proteins [ 1,2] . It is desirable to obtain additional comparative information on histones in general. Such investigations in plants are hampered by the low nucleoprotein concentration of plant cells and the difficulty of separating the nucleoprotein complex of vegetative tissue from the non-chromatin components. Using pollen as a source of nucleoprotein should overcome some of these difficulties. The male cones of the gymnosperm Encephalartos cuffer (cycad) yielded large amounts of pollen from which we isolated nucleoprotein in high yields. We wish to report the isolation of this cycad nucleoprotein and subfractionation of its histones into various groups according to their solubility and behaviour on gel exclusion chromatography. The partial amino acid sequence of the histone F3 isolated from this source has been published in a previous communication [3].