Self-assembled peptide fibrils with pH-sensitive reversible surface-active properties

Dao, Huy Minh; Parajuli, Sanjiv; Ureña-Benavides, Esteban E.; Jo, Seong Mu

doi:10.1016/j.colcom.2020.100325

Cited by 8 publications

(12 citation statements)

References 23 publications

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“…Since lactoferrin is a highly positively charged protein, the negatively charged multivalent phosphate ions can act as physical cross-links to form oligomers via electrostatic attraction. 41 The protein monomer content was close to 100% in the absence of multivalent ions (Scheme 2 and Fig. 6B).…”

Section: Resultsmentioning

confidence: 70%

“…The higher pH and ionic strength likely screened the electrostatic repulsion between adjacent molecules, enabling the protein to pack more tightly at the interface, resulting in lower interfacial tension. 41 The phosphate ions can also act as a physical crosslinking agent to form a more rigid protein film at the interface, thus resisting ambient vibration. 42 As a result, the relative amount of noise or fluctuation in the signal was much lower in the PBS samples than in water samples with the same protein concentration (Fig.…”

Section: Resultsmentioning

confidence: 99%

“…2B). 41 To investigate the interfacial activity of lactoferrin, the protein solution was dispensed at 10 µL/s into ~10 µL droplets, resulting in a < 1 s preparation time before recording the measurements. Notably, the surface tension of the PBS samples with protein concentrations > 156 µg/mL began at a value different from 72 mN/m, which is the surface tension of pure water (Fig.…”

Section: Resultsmentioning

confidence: 99%

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Degradation of lactoferrin caused by droplet atomization process via two-fluid nozzle: The detrimental effect of air–water interfaces

Dao

Sahakijpijarn²,

Chrostowski

et al. 2021

Preprint

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Biological macromolecules, especially therapeutic proteins, are delicate and highly sensitive to degradation from stresses encountered during the manufacture of dosage forms. Thin film freeze drying (TFFD) and spray freeze drying (SFD) are two processes used to convert liquid forms of protein into dry powders. In the production of inhalable dry powders that contain proteins, these potential stressors fall into three categories based on their occurrence during the primary steps of the process: (1) droplet formation (e.g., the mechanism of droplet formation, including spray atomization), (2) freezing, and (3) frozen water removal (e.g., sublimation). This study compares the droplet formation mechanism used in TFFD and SFD by investigating the effects of spray-ing on the stability of proteins, using lactoferrin as a model. This study considers various perspectives on the degradation (e.g., conformation) of lactoferrin after subjecting the protein solution to the atomization process using a pneumatic two fluid nozzle (employed in SFD) or a low shear drop application through the nozzle. The surface activity of lactoferrin was examined to explore the interfacial adsorption tendency, diffusion, and denaturation process. Subsequently, this study also investigates the secondary and tertiary structure of lactoferrin, the quantification of monomers, oligomers, and ultimately, aggregates. The spraying process affected the tertiary structure more negatively than the tightly woven secondary structure, resulting in a 1.5 nm red shift in peak position corresponding to the Tryptophan (Trp) residues. This conformational change can either (a) be reversed at low concentrations via relaxation or (b) proceed to form irreversible aggregates at higher concentrations. Interestingly, when the sample was allowed to progress into micron sized aggregates, such a dramatic change was not detected using methods such as size-exclusion chromatography, polyacrylamide gel electrophoresis, and dynamic light scattering at 173 degrees. A more complete understanding of the heterogeneous protein sample was achieved only through a combination of 173 degrees and 13 degrees backward and forward scattering, a combination of derived count rate measurements, and microflow imaging (MFI). Finally, compared to the low shear dripping used in the TFFD process, lactoferrin underwent a relatively fast conformational change upon exposure to the high air water interface of the two-fluid atomization nozzle used in the SFD process as compared to the low shear dripping used in the TFFD process. The interfacial induced denaturation that occurred during spraying was governed primarily by the size of the atomized droplets, regardless of the duration of exposure to air.

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Section: Resultsmentioning

confidence: 70%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Degradation of lactoferrin caused by droplet atomization process via two-fluid nozzle: The detrimental effect of air–water interfaces

Dao

Sahakijpijarn²,

Chrostowski

et al. 2021

Preprint

View full text Add to dashboard Cite

show abstract

“…However, the surface tensions of the three peptides were slightly different because of their different amino acid composition. It is reported that the primary intermolecular interaction hindering self‐assembly is the electrostatic repulsion between positively charged Lys and Arg residues (Dao et al, 2020). In the acidic environment, the repulsive force produced by positively charged Lys and Arg residues is dominant, which effectively hinders the elongation of peptide aggregates, so the peptides are dispersed in solution and the surface activity is strong (Neda Habibi et al, 2016).…”

Section: Resultsmentioning

confidence: 99%

“…The peptides were dissolved in ultra‐pure water, and the solution pH was regulated by 5% HCl and 5 M NaOH to prepare different pH (pH = 3, 5, 7, 9, 11) peptides with a concentration of 1 × 10 −3 mol L −1 , which were poured into the determination plate. After the solution was in a stable state, the sample is measured by a surface tensiometer (Dao et al, 2020). Each sample was determined for three times, and the results were taken as the average value of three times.…”

Section: Methodsmentioning

confidence: 99%

Biological preparation and characterization of surfactant‐like peptides

Meng

Wang

et al. 2022

J Surfact & Detergents

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Surfactant-like peptides are a class of small molecule short peptides with surface activity designed independently by imitating the structural characteristics of natural lipid molecules. Surfactant-like peptides have the advantages of no pollution to the environment, easy biodegradation, strong bacteriostasis, and nutrition, which accords with the development concept of the modern green industry. They are widely used in many fields such as cleaning, food, cosmetics, medicine. At present, such surfactants are mainly synthesized by expensive chemical methods. The efficient synthesis of surfactant-like peptides by biological methods has become a significant research direction. This method is environmentally friendly and can achieve low-cost and efficient production. In this study, three novel surfactant-like peptides were designed and synthesized by biological methods and successfully expressed in vitro. By optimizing of the expression host, expression vector, and fermentation conditions, the optimal expression amount was finally obtained. In addition, these surfactant-like peptides were found to have good surface activity and low critical micelle concentration. More importantly, they are pH-responsive and can self-assemble to form nanostructures in different solutions, which provides essential research value for the production of novel nanomaterials in the future. This study is the first to construct and express three novel surfactant-like peptides by biological methods, which effectively reduce the production cost compared to chemical methods; and it was also found to have excellent surfactant properties. This provides the basis for large-scale industrial production and application.

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Self‐assembling Peptides with Internal Ionizable Unnatural Amino Acids: A General Approach to pH‐responsive Peptide Materials

Asokan-Sheeja

Yang

Adones

et al. 2022

Chemistry An Asian Journal

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Self‐assembled peptides are an emerging family of biomaterials that show great promise for a range of biomedical and biotechnological applications. Introducing and tuning the pH‐responsiveness of the assembly is highly desirable for improving their biological activities. Inspired by proteins with internal ionizable residues, we report a simple but effective approach to constructing pH‐responsive peptide assembly containing unnatural ionic amino acids with an aliphatic tertiary amine side chain. Through a combined experimental and computational investigation, we demonstrate that these residues can be accommodated and stabilized within the internal hydrophobic compartment of the peptide assembly. The hydrophobic microenvironment shifts their pKa significantly from a basic pH typically found for free amines to a more biologically relevant pH in the weakly acidic range. The pH‐induced ionization and ionization‐dependent self‐assembly and disassembly are thoroughly investigated and correlated with the biological activity of the assembly. This new approach has unique advantages in tuning the pH‐responsiveness of self‐assembled peptides across a large pH range in a complex biological environment. We anticipate the ionizable amino acids developed here can be widely applicable to the synthesis and self‐assembly of many amphiphilic peptides with endowed pH‐responsive properties to enhance their biological activities toward applications ranging from targeted therapeutic delivery to proton transport.

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Self-assembled peptide fibrils with pH-sensitive reversible surface-active properties

Cited by 8 publications

References 23 publications

Degradation of lactoferrin caused by droplet atomization process via two-fluid nozzle: The detrimental effect of air–water interfaces

Degradation of lactoferrin caused by droplet atomization process via two-fluid nozzle: The detrimental effect of air–water interfaces

Biological preparation and characterization of surfactant‐like peptides

Self‐assembling Peptides with Internal Ionizable Unnatural Amino Acids: A General Approach to pH‐responsive Peptide Materials

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