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Start Over Author "Castillo, Johanna" Topic antimicrobial peptides
3 results on '"Castillo, Johanna"'

1. One-pot synthesis of alginate-antimicrobial peptide nanogel.

Author

Salvati, Brianne, Flórez-Castillo, Johanna Marcela, Santagapita, Patricio Román, Barja, Beatriz C., and Perullini, Mercedes

Subjects
*ANTIMICROBIAL peptides, *PEPTIDE synthesis, *SMALL-angle X-ray scattering, *PEPTIDES, *TRYPSIN, *NANOPARTICLES, *ALGINATES
Abstract

Nanosized alginate-based particles (NAPs) were obtained in a one-pot solvent-free synthesis procedure, achieving the design of a biocompatible nanocarrier for the encapsulation of IbM6 antimicrobial peptide (IbM6). IbM6 is integrated in the nascent nanosized hydrogel self-assembly guided by electrostatic interactions and by weak interactions, typical of soft matter. The formation of the nanogel is a dynamic and complex process, which presents an interesting temporal evolution. In this work, we optimized the synthesis conditions of IbM6-NAPs based on small-angle X-ray scattering (SAXS) measurements and evaluated its time evolution over several weeks by sensing the IbM6 environment in IbM6-NAPs from photochemical experiments. Fluorescence deactivation experiments revealed that the accessibility of different quenchers to the IbM6 peptide embedded in NAPs is dependent on the aging time of the alginate network. Lifetimes measurements indicate that the deactivation paths of the excited state of the IbM6 in the nanoaggregates are reduced when compared with those exhibited by the peptide in aqueous solution, and are also dependent on the aging time of the nanosized alginate network. Finally, the entrapment of IbM6 in NAPs hinders the degradation of the peptide by trypsin, increasing its antimicrobial activity against Escherichia coli K-12 in simulated operation conditions. [ABSTRACT FROM AUTHOR]

Published
2024
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2. Antibacterial Activity against Clinical Isolates of Escherichia coli and Molecular Docking

Author

Flórez Castillo, Johanna-Marcela, Rondón Villarreal, Paola, Ropero Vega, José Luis, Mendoza Espinel, Stephany Y., Moreno Amézquita, July A., Méndez Jaimes, Karen D., Farfán García, Ana Elvira, Gómez Rangel, Sergio-Yebrail, Gómez-Duarte, Oscar G., and Universidad de Santander

Subjects
Péptidos antimicrobianos, Molecular docking, Escherichia coli, Antimicrobial peptides, Acoplamiento molecular
Abstract

1 p., El péptido Ib-M6 tiene actividad antibacteriana contra la cepa K-12 de Escherichia coli no patógena . La primera parte de este estudio determina la actividad antibacteriana de Ib-M6 contra catorce cepas patógenas de E. coli O157: H7. El ensayo de susceptibilidad mostró que Ib-M6 tenía valores de Concentración Inhibitoria Mínima (MIC) más bajos que la estreptomicina, usada como antibiótico de referencia. Además, para predecir la posible interacción entre Ib-M6 y los componentes de la membrana externa de E. coli, utilizamos simulaciones de acoplamiento molecular donde la proteína FhuA y su complejo con Lipopolisacárido (LPS-FhuA) se utilizaron como objetivos del péptido. Los complejos FhuA / Ib-M6 tenían valores de energía entre -39,5 y -40,5 unidades de energía Rosetta (REU) y solo un enlace de hidrógeno. En contraste, los complejos entre LPS-FhuA e Ib-M6 mostraron valores de energía entre -25,6 y -40,6 REU, y la presencia de cinco posibles enlaces de hidrógeno. Por tanto, la actividad antimicrobiana del péptido Ib-M6 mostrada en los ensayos experimentales podría deberse a su interacción con la membrana externa de E. coli ., The Ib-M6 peptide has antibacterial activity against non-pathogenic Escherichia coli K-12 strain. The first part of this study determines the antibacterial activity of Ib-M6 against fourteen pathogenic strains of E. coli O157:H7. Susceptibility assay showed that Ib-M6 had values of Minimum Inhibitory Concentration (MIC) lower than streptomycin, used as a reference antibiotic. Moreover, to predict the possible interaction between Ib-M6 and outer membrane components of E. coli, we used molecular docking simulations where FhuA protein and its complex with Lipopolysaccharide (LPS–FhuA) were used as targets of the peptide. FhuA/Ib-M6 complexes had energy values between 􀀀39.5 and 􀀀40.5 Rosetta Energy Units (REU) and only one hydrogen bond. In contrast, complexes between LPS–FhuA and Ib-M6 displayed energy values between 􀀀25.6 and 􀀀40.6 REU, and the presence of five possible hydrogen bonds. Hence, the antimicrobial activity of Ib-M6 peptide shown in the experimental assays could be caused by its interaction with the outer membrane of E. coli., Ej. 1

Published
2020

3. Cambios en el perfil protéico de E. coli O157:H7 frente al tratamiento con Ib-M1 e IONP@Ib-M1.

Author

Smith Ramíez-Forero, Gloria, Valdivieso-Quintero, Wilfredo, Luis Ropero-Vega, José, Zafra, German, and Marcela Flórez-Castillo, Johanna

Subjects
ESCHERICHIA coli O157:H7, AMINO acid transport, ACYL group, TWO-dimensional electrophoresis, PATHOGENIC bacteria
Abstract

Copyright of Revista Colombiana de Química is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Published
2021
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