Design of S–S bond containing maleimide-conjugated<i>closo</i>-dodecaborate (SSMID): identification of unique modification sites on albumin and investigation of intracellular uptake

Abstract

An S-S bond containing maleimide-conjugated closo-dodecaborate (SSMID) was synthesised for identification of albumin binding sites. Three Lys residues, Lys221, Lys413 and Lys431, were identified as SSMID modification sites in addition to Cys34 in bovin serum albumin (BSA). Fluorescent-labelled MID-BSA was found to be accumulated in the cytosol of HeLa cells.