Polypeptide A9K at Nanoscale Carbon: Simulation Study

TL;DR

This simulation study investigates how the A9K polypeptide interacts with nanoscale carbon structures like carbon nanotubes and graphene, revealing thermodynamically favorable binding that supports non-covalent functionalization for biomedical applications.

Contribution

It provides detailed molecular dynamics insights into A9K peptide binding mechanisms with nanoscale carbons, highlighting potential for functionalization in nanobiotechnology.

Findings

Binding is thermodynamically favorable in all cases.

Encapsulation in USCNT is highly favorable.

Binding to graphene is stronger than to USCNT outer walls.

Abstract

An amphiphilic nature of the surfactant-like peptides is responsible for their propensity to aggregate at the nanoscale. These peptides can be readily used for a non-covalent functionalization of nanoparticles and macromolecules. This work reports an observation of supramolecular ensembles consisting of ultrashort carbon nanotubes (USCNTs), graphene (GR) and A9K polypeptide formed by lysine and arginine. Potential of mean force (PMF) is used as a major descriptor of the CNT-A9K and GR-A9K binding process, supplementing structural data. The phase space sampling is performed by multiple equilibrium molecular dynamics simulations with position restraints, where applicable. Binding in all cases was found to be thermodynamically favorable. Encapsulation in the (10,10) USCNT is particularly favorable. Curvature of external surface does not favor binding. Thus, binding of A9K at GR is stronger than its binding at the outer sidewall of USCNTs. Overall, the presented results favor non-covalent functionalization of nanoscale carbons that are considered interesting in the fields of biomaterials, biosensors, biomedical devices, and drug delivery.