Enzymatic removal of protein fouling from self-assembled cellulosic nanofilms: experimental and modeling studies

Protein fouling is a serious problem in many food, pharmaceutical and household industries. In this work, the removal of rubisco protein fouling from cellulosic surfaces using a protease (subtilisin A) has been investigated experimentally and mathematically. The cellulosic surfaces were prepared using self-assembled monolayers (SAMs) on a surface plasmon resonance biosensor (chip) surface after conjugating cellulose to α-lipoic acid. Rubisco adsorption on the prepared cellulosic SAMs was found to be irreversible, leading to the creation of a tough protein fouling. The heterogeneous enzymatic cleansing of such tough fouling involves enzyme transfer to the surface and the subsequent removal of the rubisco via protease activity. In this work, these two processes were decoupled, allowing enzyme transfer and enzymatic surface reaction to be parameterized separately. Mathematical modeling of the enzymatic cleaning of protein fouling from cellulosic SAMs revealed that enzymatic mobility at the interface is an important factor. The approach presented in this work might be useful in designing better protein fouling-resistant surfaces. It could also be used to guide efforts to screen and gauge the cleaning performance of detergent-enzyme formulations.