mPEG-Boronic Acid MW 5k

mPEG-Boronic Acid. The boronic acid uses phenyl boronic acid (PBA) is mPEG-PBA. PEG modified with boronic acid permits site specific PEGylation of glycoproteins or glycans. Boronic acid reversibly react with cis-diol on the glycan of glycoprotein, and the covalent affinity binding is reversible with the change of pH. Glycoproteins influence a broad spectrum of biological processes including cell-cell interaction, host-pathogen interaction, or protection of proteins against proteolytic degradation. The reversible covalent interaction of boronic acid with cis-1,2- or 1,3-diols to form five- or six-membered cyclic esters, respectively, has proven sufficiently strong, enabling binding of saccharides at mM or sub-mM levels. The generally observed binding affinity of phenylboronic acid (PBA) with monosaccharides follows the order of fructose > galactose > mannose > glucose.