Randomly phosphorylated polystyrene derivatives interact with RNA polymerase II transcription factors: Part I

Abstract

Insoluble functional synthetic random copolymers are able to develop at their surfaces specific interactions with biologic components. Crosslinked phosphorylated polystyrene derivatives were previously shown to mimic DNA antigen because they interacted with anti-DNA antibodies found in the sera of systemic lupus erythematosus patients. These biospecific surfaces were postulated to be able to bind other DNA-binding proteins such as RNA polymerase II transcription factors. Indeed, these proteins play a major role in gene regulation in mammalian cells. This hypothesis was checked by adsorption and elution of HeLa cell nuclear extracts on a 72% phosphorylated resin. The composition of the eluted fractions were analyzed by electrophoresis, and the biologic activity of the transcription factors was tested using an in vitro transcription assay. The results showed that USF, TATA-binding protein (TBP), and TFIIB were specifically adsorbed on the polymer and that all eluted factors kept their biologic activity. Therefore, randomly phosphorylated polystyrene derivatives may be useful for the fractionation of RNA polymerase II transcription factors.

Cellulose phosphates as biomaterials. II. Surface chemical modification of regenerated cellulose hydrogels

“…Once implanted, phosphorylated cellulose could promote the formation of calcium phosphates, thus having closer resemblance to bone functionality and ensuring a satisfactory bonding at the interface between hard tissue and the biomaterial. Furthermore, phosphate groups constitute adequate functionalities for specifically binding biologically active species,11–17 and this can be used as an advantage for obtaining specifically customized active surfaces. In a previous work, the phosphorylation reaction was carried out by an original reaction route 18, 19.…”