Investigation of nonfouling polypeptides of poly(glutamic acid) with lysine side chains synthesized by EDC·HCl/HOBt chemistry

Homogenous glutamic acid (E) and lysine (K) polypeptides were proposed and synthesized before. In this work, a new polypeptide formed by poly(glutamic acid) with lysine side chains (poly(E)-K) was synthesized by facile EDC·HCl/HOBt chemistry and investigated.

Results show that these polypeptides also have good nonspecific protein resistance determined by enzyme-linked immunosorbent assay. The lowest nonspecific adsorption of the model proteins, anti-IgG and fibrinogen (Fg), on the self-assembling monolayers (SAMs) surface of poly(E)-K was only 3.3 ± 1.8 and 4.4 ± 1.6%, respectively, when protein adsorption on tissue culture polystyrene surface was set as 100%. And, the relative nonspecific protein adsorption increases when the polypeptide molecular weight increases due to the repression of low density polymer brushes.