Creating Antibacterial Surfaces with the Peptide Chrysophsin-1

Abstract

Immobilization of antimicrobial peptides (AMPs) holds potential for creating surfaces with bactericidal properties. In order to successfully incorporate AMPs into desired materials, increased fundamental understanding of the relationship between AMP immobilization and the efficacy of bound peptides as antibacterial agents is required. In this study, we characterize the relationship between surface binding of the AMP and subsequent ability of the peptide to kill bacteria. Surface immobilization of the AMP chrysophsin-1 (CHY1) via a flexible linker is studied in real-time, using a quartz crystal microbalance with dissipation monitoring (QCM-D). Depending on whether the AMP is physically adsorbed to the surface or attached covalently via a zero-length or flexible cross-linker, changes could be observed in AMP orientation, surface density, flexibility, and activity against bacteria. Covalent surface binding of CHY1 led to the formation of solvated monolayers of vertically positioned peptide molecules, while the physical adsorption of CHY1 led to the deposition of rigid monolayers of horizontally positioned peptide molecules on the sensor surface. Covalently bound peptides were not removed by extensive washing and did not leach from the surface. Zero-length immobilization of the peptide decreased its ability to kill E. coli to 34% ± 7% of added bacteria, while binding via a flexible linker resulted in 82% ± 11% of bacteria being killed by the AMP.

Development of a catheter functionalized by a polydopamine peptide coating with antimicrobial and antibiofilm properties

“…To assess the long-term stability of the peptide-immobilized catheters, a leaching assay [24,32] was conducted. Briefly, the Cat-PD-CWR11 samples were immersed in deionized water for 1, 3, 7, 14, 21 and 30 days and subjected to antimicrobial assay (Section 2.6.1).…”

Proposed Mechanisms of Tethered Antimicrobial Peptide Chrysophsin-1 as a Function of Tether Length Using QCM-D

“…25 The quartz-crystal microbalance with dissipation monitoring (QCM-D) has emerged as a convenient nondestructive method to measure surface interactions in real time between AMPs and membranes. 28,45 QCM-D quantifies changes in frequency (Δf) and dissipation (ΔD) that correspond to changes in mass deposition (Δm) and film rigidity, respectively, on the surface of oscillating piezoelectric quartz crystal sensors with nanogram-level sensitivity. It is a nondestructive flow technique, allowing for coupling to other experiments.…”

Poly(l-lysine) Interfaces via Dual Click Reactions on Surface-Bound Custom-Designed Dithiol Adsorbates

“…[4][5][6][7] Therefore, controlled surface modification becomes a key aspect in the design of a functionalized interface for specific applications.…”

“…The second step involved a thiol-Michael addition of the cysteine-terminated poly-L-lysine to the maleimide and was conducted under ambient conditions; 19 this latter reaction has been used in a wide variety of materials/biomaterials applications. 2,15,20 The use of a short-chained dithiol platform for producing a polypeptide interface offers at least three advantages when compared to related approaches involving the physisorption of peptides: 5,21 (1) a reliable site for covalent attachment of peptide molecules, (2) a highly stable monolayer on the surface, 22,23 and (3) circumvention of problems that are encountered when using adsorbates having long alkyl chains (e.g., disarray in the resulting peptide films). Further, the minor differences in structure between the two dithiol adsorbates provide an opportunity to assess the value of the added conformational mobility afforded by a limited increase in the length of the alkyl spacer extending from the rigid aromatic ring.…”