We investigated a viscous protein layer formed on self-assembled monolayers (SAMs) in crowded biological environments. The results were obtained through force spectroscopic measurements using colloidal probes and substantiated by exhaustive analysis using a quartz crystal microbalance with an energy dissipation technique. A hydrophobic SAM of n-octanethiol (C8 SAM) in bovine serum albumin (BSA) solution is buried under an adlayer of denatured BSA molecules and an additional viscous interphase layer that is five times more viscous than the bulk solution. C8 SAMs in fetal bovine serum induced a formation of a thicker adsorbed protein layer but with no observable viscous interphase layer. These findings show that a fouling surface is essentially inaccessible to any approaching molecules and thus has a new biological and physical identity arising from its surrounding protein layers. In contrast, the SAMs composed of sulfobetaine-terminated alkanethiol proved to be sufficiently protein-resistant and bio-inert even under crowded conditions due to a protective barrier of its interfacial water, which has implications in the accurate targeting of artificial particles for drug delivery and similar applications by screening any non-specific interactions. Finally, our strategies provide a platform for the straightforward yet effectual in vitro characterization of diverse types of surfaces in the context of targeted interactions in crowded biological environments.
Biomolecules interact with their target molecules accurately in crowded conditions in cells or bodies with rarely making mistakes (non-specific binding). In this review, we discuss the mechanism underlying the accuracy in the molecular recognition of biomolecules, in particular, the suppression of non-specific interactions. Our surface force measurements revealed that water-mediated force critically governs the colloidal stability of Au nanoparticles covered with DNA molecules. The colloidal stability depended on the complementarity of the terminal base pairs. In the case of the peptide molecules, the SAMs of peptide that contains zwitterionic pairs of glutamic acids and lysines exhibited excellent anti-fouling properties, whereas the SAMs of peptide that possesses glutamic acids and arginines did not. We also found that interfacial water plays an essential role as a barrier preventing the approach of proteins and cells. From these findings, we are noticing that biomolecules smartly use their interfacial water to accomplish their specific interactions.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.