The class I Hydrophobin EAS, found in the fungus Neurospora crassa[1], is part of a family of small, amphiphilic fungal proteins best known for their ability to self-assemble into stable monolayers, on hydrophobic as well as hydrophilic surfaces[2-3]. These proteins possess a distinct amphipathic character and can condition the surface to facilitate further microbial growth. In fact many aspects of fungal development have been attributed to these proteins and being able to control their adhesion will facilitate in the design of improved coatings. In this study, we use molecular dynamic simulations to investigate the binding properties of EAS hydrophobin with silica based coatings with and without the presence PEG, one of the most widely used surface protectors[4-5]. Particularly attention was paid to the effects of PEG on protein denaturing and the evolution of the secondary and tertiary structure. Results show that at high PEG coverage density, the protein undergoes denaturation, with a loss in its secondary structure, accompanied by swelling of the protein.
References:
[1]Macindoe I., Kwan A., Ren Q., Morris V., Yang W., Mackay J., and Sunde M., Self-assembly of functional, amphipathic amyloid monolayers by the fungal hydrophobin EAS, PNAS Early Edition, 2012, 1-8.
[2] Qin, M., Wang, L.K., Feng, X.Z., Yang, Y.L., Wang, R., Wang, C., Yu, L., Shao, B., Qiao, M.Q., Bioactive surface modification of mica and poly(dimethylsiloxane) with hydrophobins for protein immobilization. Langmuir 2007, 23, 4465–4471.
[3] Zhao, Z.-X., Qiao, M.-Q., Yin, F., Shao, B., Wu, B.-Y., Wang, Y.-Y., Wang, X.-S., Qin, X., Li, S., Yu, L., Chen, Q., Amperometric glucose biosensorbased on self-assembly hydrophobin with high efficiency of enzyme utilization. Biosens. Bioelectron. 2007, 22, 3021–3027.
[4]Hamilton-Brown, P, Gengenbach, T, Griesser, HJ & Meagher, L 2009, 'End terminal, poly(ethylene oxide) graft layers: surface forces and protein adsorption', Langmuir, vol. 25, no. 16, pp. 9149-56.