26] Chemical cross-linking of histones

Abstract

Publisher Summary This chapter focuses on the chemical cross linking of histones. Bifunctional reagents, particularly those that react with amino groups, which are generally accessible on protein surfaces, have proved useful in the analysis of several features of chromatin structure. Broadly, information may be gained at three levels. First, and most simply, the oligomeric state of the histones and the stability of histone oligomers as a function of protein concentration and ionic strength may be determined from the relative molecular masses of the cross-linked oligomers, which are most easily estimated by polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate (SDS). Second, the nearest neighbors within a protein oligomer may be determined. In this case, cleavable cross-linkers are needed so that fractionated cross-linked products may be cleaved at the cross-links to regenerate their component histones for identification.