Specific binding of glucosaminylmuramyl peptides to histones

Intracellular N-acetylglucosaminylmuramyl peptide-binding proteins of murin e macrophages and myelomonocytic WEHI-3 cells were characterized, SDS-PAGE and Western blotting revealed proteins with molecular masses of 18, 32 and 34 kDa retaining the ability to specifically hind glucosaminylmuramyl dipep tide. The inhibition analysis demonstrated that only biologically active mu ramyl peptides but not inactive analogs or fragments of glucosaminylmuramyl dipeptide could inhibit glucosaminylmuramyl dipeptide-binding to these pro teins. Purification of these proteins and sequencing of peptides obtained a fter in-gel trypsin digestion enabled us to identify the above mentioned pr oteins as histones H1 and H3. These findings suggest that nuclear histones might be target molecules for muramyl peptides. (C) 1999 Federation of Euro pean Biochemical Societies.