Antimicrobial nano-assemblies of tryptocidine C, a tryptophan-rich cyclic decapeptide, from ethanolic solutions

Vikas Kumar, Wilma van Rensburg, Jacky L. Snoep, Henrich H. Paradies, Christopher Borrageiro, Carmen de Villiers, Ramesh Singh, Khashti Ballabh Joshi, Marina Rautenbach*

*Corresponding author for this work

Research output: Contribution to JournalArticleAcademicpeer-review

21 Downloads (Pure)

Abstract

Tryptocidine C (TpcC), a Trp-rich cyclodecapeptide is a minor constituent in the antibiotic tyrothricin complex from Brevibacillus parabrevis. TpcC possesses a high tendency to oligomerise in aqueous solutions and dried TpcC forms distinct self-assembled nanoparticles. High-resolution scanning electron microscopy revealed the influence of different ethanol:water solvent systems on TpcC self-assembly, with the TpcC, dried from a high concentration in 15% ethanol, primarily assembling into small nanospheres with 24.3 nm diameter and 0.05 polydispersity. TpcC at 16 μM, near its CMC, formed a variety of structures such as small nanospheres, large dense nanospheroids and facetted 3-D-crystals, as well as sheets and coarse carpet-like structures which depended on ethanol concentration. Drying 16 μM TpcC from 75% ethanol resulted in highly facetted 3-D crystals, as well as small nanospheres, while those in 10% ethanol preparation had less defined facets. Drying from 20 to 50% ethanol led to polymorphic architectures with a few defined nanospheroids and various small nanoparticles, imbedded in carpet- and sheet-like structures. These polymorphic surface morphologies correlated with maintenance of fluorescence properties and the surface-derived antibacterial activity against Staphylococcus aureus over time, while there was a significant change in fluorescence and loss in activity in the 10% and 75% preparations where 3-D crystals were observed. This indicated that TpcC oligomerisation in solutions with 20–50% ethanol leads to metastable structures with a high propensity for release of antimicrobial moieties, while those leading to crystallisation limit active moieties release. TpcC nano-assemblies can find application in antimicrobial coatings, surface disinfectants, food packaging and wound healing materials.

Original languageEnglish
Pages (from-to)22-32
Number of pages11
JournalBiochimie
Volume204
Early online date31 Aug 2022
DOIs
Publication statusPublished - Jan 2023

Bibliographical note

Funding Information:
This research was funded by the BIOPEP™ Peptide Fund managed by MR. VK thanks Stellenbosch University Sub-committee B and acknowledges Claude Leon Foundation for sponsoring his postdoctoral research fellowship. KBJ acknowledges funding from SERB-India (CRB/2021/000759). RS acknowledges funding from CSIR-UGC-India for a senior research fellowship. JLS acknowledges funding from the DST/NRF, particularly for funding the SARCHI initiative (NRF-SARCHI-82813). The authors thank Prof. Lydia-Marie Joubert and Madelaine Frazenburg at the University of Stellenbosch Central Analytical Facility (CAF) for Electron Microscopy and their guidance during SEM analysis. We acknowledge the CAF Units, Stellenbosch University, South Africa for the use of instrumentation in the SEM and LC-MS Units.

Funding Information:
This research was funded by the BIOPEP™ Peptide Fund managed by MR. VK thanks Stellenbosch University Sub-committee B and acknowledges Claude Leon Foundation for sponsoring his postdoctoral research fellowship. KBJ acknowledges funding from SERB-India ( CRB/2021/000759 ). RS acknowledges funding from CSIR-UGC -India for a senior research fellowship. JLS acknowledges funding from the DST / NRF , particularly for funding the SARCHI initiative ( NRF-SARCHI-82813 ). The authors thank Prof. Lydia-Marie Joubert and Madelaine Frazenburg at the University of Stellenbosch Central Analytical Facility (CAF) for Electron Microscopy and their guidance during SEM analysis. We acknowledge the CAF Units, Stellenbosch University, South Africa for the use of instrumentation in the SEM and LC-MS Units.

Publisher Copyright:
© 2022 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM)

Funding

This research was funded by the BIOPEP™ Peptide Fund managed by MR. VK thanks Stellenbosch University Sub-committee B and acknowledges Claude Leon Foundation for sponsoring his postdoctoral research fellowship. KBJ acknowledges funding from SERB-India (CRB/2021/000759). RS acknowledges funding from CSIR-UGC-India for a senior research fellowship. JLS acknowledges funding from the DST/NRF, particularly for funding the SARCHI initiative (NRF-SARCHI-82813). The authors thank Prof. Lydia-Marie Joubert and Madelaine Frazenburg at the University of Stellenbosch Central Analytical Facility (CAF) for Electron Microscopy and their guidance during SEM analysis. We acknowledge the CAF Units, Stellenbosch University, South Africa for the use of instrumentation in the SEM and LC-MS Units. This research was funded by the BIOPEP™ Peptide Fund managed by MR. VK thanks Stellenbosch University Sub-committee B and acknowledges Claude Leon Foundation for sponsoring his postdoctoral research fellowship. KBJ acknowledges funding from SERB-India ( CRB/2021/000759 ). RS acknowledges funding from CSIR-UGC -India for a senior research fellowship. JLS acknowledges funding from the DST / NRF , particularly for funding the SARCHI initiative ( NRF-SARCHI-82813 ). The authors thank Prof. Lydia-Marie Joubert and Madelaine Frazenburg at the University of Stellenbosch Central Analytical Facility (CAF) for Electron Microscopy and their guidance during SEM analysis. We acknowledge the CAF Units, Stellenbosch University, South Africa for the use of instrumentation in the SEM and LC-MS Units.

FundersFunder number
CSIR-UGC
CSIR-UGC-India
SERB-IndiaCRB/2021/000759
University of Stellenbosch Central Analytical Facility
Claude Leon Foundation
Department of Science and Technology, Republic of South AfricaNRF-SARCHI-82813
Department of Science and Technology, Republic of South Africa
Universiteit Stellenbosch
China-ASEAN Investment Cooperation Fund

    Keywords

    • Antimicrobial activity
    • Antimicrobial cyclic peptide
    • Morphology
    • Nanocrystals
    • Self-assembly
    • Surface activity
    • Tryptocidine
    • Tyrothricin

    Fingerprint

    Dive into the research topics of 'Antimicrobial nano-assemblies of tryptocidine C, a tryptophan-rich cyclic decapeptide, from ethanolic solutions'. Together they form a unique fingerprint.

    Cite this