pH and temperature-dependent structural and functional stability of hemocyanin from Tachypleus gigas: A multispectroscopic, phenoloxidase activity and computational study.
Tachypleus gigas hemocyanin retains 80% phenoloxidase activity up to 70 °C, indicating notable stability under varying conditions.
Where it sits
this study against the rest of the ghk-cu corpusSummary and findings
The study evaluated the structural and functional stability of Tachypleus gigas hemocyanin (TgH) across various temperatures and pH conditions. TgH retained 80% phenoloxidase activity up to 70 °C and demonstrated a melting temperature of 77.98 °C. The findings suggest potential applications in therapeutic and biotechnological fields.
Abstract
Hemocyanin, primarily an oxygen-transporting protein, has gained considerable attention due to its multifunctional role in therapeutic and biotechnological applications. A detailed assessment of structural and functional stability is crucial for its potential usage in various applications. Towards this, the stability of Tachypleus gigas hemocyanin (TgH) was evaluated across various temperatures and pH conditions. UV-visible spectroscopy confirmed stable oxygen binding at the di‑copper active site up to 50 °C between pH 5.0 and 8.0. Circular dichroism spectroscopy revealed a melting temperature of 77.98 °C and demonstrated that TgH successfully refolds into its native conformation from 70 °C upon removing thermal stress. Functional assay showed that TgH retains 80% phenoloxidase activity up to 70 °C, indicating remarkable functional stability and reversibility. Dynamic light scattering analysis revealed a decrease in particle diameter from 25.95 nm at pH 6.0 to 8.07 nm at pH 10.0, suggesting alkaline dissociation of oligomers into monomers, potentially due to electrostatic repulsion between subunits because of increased negative surface charge. Finally, molecular dynamics simulations corroborated these findings by demonstrating that the TgH subunit maintains its original conformation up to 70 °C, with notable deviations observed beyond this temperature, consistent with the experimental results. The structure remains stable without any notable deviation at pH 6.0 and 10.0, indicating structural stability of the monomer subunit despite alkaline dissociation. This comprehensive study highlights the thermostability and broad pH tolerance of TgH, emphasizing its potential for diverse therapeutic and biotechnological applications, especially in fluctuating environmental conditions.
Background
This paper addresses the stability of hemocyanin, a protein known for its role in oxygen transport, particularly its structural and functional stability under varying temperature and pH conditions. Previous studies have indicated the importance of hemocyanin's stability for its applications in biotechnology and therapeutics. Understanding these properties is essential for optimizing its use in fluctuating environmental conditions.
Methods
The study utilized UV-visible spectroscopy, circular dichroism spectroscopy, functional assays, dynamic light scattering analysis, and molecular dynamics simulations to assess the stability of TgH. The population studied was Tachypleus gigas hemocyanin. Specific temperatures and pH levels were tested, but exact dosages or concentrations were not reported. The primary outcome measures included oxygen binding stability, melting temperature, phenoloxidase activity, and particle size.
Results
The primary endpoint indicated that TgH retained 80% phenoloxidase activity up to 70 °C. The melting temperature was reported as 77.98 °C. The study also noted a decrease in particle diameter from 25.95 nm at pH 6.0 to 8.07 nm at pH 10.0, suggesting structural changes under alkaline conditions.
Interpretation
These findings align with prior literature on hemocyanin stability, indicating that TgH exhibits significant thermal and pH tolerance. While the results are statistically significant, the clinical relevance remains uncertain without direct applications or human data. Limitations such as the lack of long-term follow-up and potential confounding factors in the experimental design may affect the robustness of these conclusions.
Key findings
- Stable oxygen binding confirmed up to 50 °C between pH 5.0 and 8.0.
- Melting temperature of TgH was 77.98 °C.
- TgH retained 80% phenoloxidase activity up to 70 °C.
- Particle diameter decreased from 25.95 nm at pH 6.0 to 8.07 nm at pH 10.0.
- Molecular dynamics simulations showed TgH subunit maintains original conformation up to 70 °C.
Limitations
- Not reported in abstract.
- Experimental conditions may not reflect in vivo environments.
- No long-term stability data provided.
- Potential confounding factors not addressed.