RECONSTITUTION OF NATIVE-LIKE NUCLEOSOME CORE PARTICLES FROM REVERSED-PHASE-HPLC-FRACTIONATED HISTONES

We have reconstituted nucleosome core particles from reversed-phase-HP LC-purified chicken erythrocyte core histones and 145 bp random-sequen ce DNA fragments. Characterization of the resulting nucleoprotein comp lexes by sedimentation velocity, CD and DNase I footprinting showed th at they are structurally indistinguishable from native nucleosome core particles. Furthermore, we have shown that the ability to reproduce t hese native-like structural features in these reconstituted nucleosome core particles is basically independent of the biological source or t he method used (i.e. salt versus acid) for the extraction of histones before their HPLC fractionation. The usefulness and relevance of this approach for the reconstitution of native-like chromatin structures fr om histone types (histone variants/post-translationally modified histo nes), which are usually available only in relatively small amounts, is discussed.