Nanodevice-induced conformational and functional changes in a prototypical calcium sensor protein

Area of Science:

• Biophysics
• Nanotechnology
• Cellular Biology

Background:

• Calcium ions (Ca2+) are vital intracellular messengers regulating numerous cellular functions.
• Calcium sensor proteins detect Ca2+ concentration changes, modulating cellular activities through conformational shifts.
• Investigating the interaction between nanodevices and Ca2+ sensors is crucial for developing biocompatible nanomedicines.

Purpose of the Study:

• To evaluate the structural and functional impact of nanodevice interactions on Ca2+ sensor proteins.
• To compare the biocompatibility of calcium fluoride nanoparticles (NPs) and liposomes as carriers for Ca2+ sensors.
• To assess the potential of these nanodevices for biomedical applications involving Ca2+ sensing.

Main Methods:

• Incubation of the Ca2+ sensor recoverin (Rec) with CaF2 nanoparticles and liposomes.
• Circular dichroism and fluorescence spectroscopy to analyze protein structure and thermal stability.
• Dynamic light scattering to measure hydrodynamic diameter and spectroscopic methods to assess Ca2+ sensing capability.

Main Results:

• Calcium fluoride nanoparticles significantly altered Rec conformation, thermal stability, and Ca2+ sensing capability.
• Liposomes minimally affected Rec structure and function, facilitating reversible binding.
• NP-bound Rec retained an all-helical fold but exhibited reduced thermal stability and increased unfolding cooperativity.

Conclusions:

• Nanoparticle characteristics critically influence the structure and function of Ca2+ sensor proteins.
• Liposomes demonstrate better biocompatibility for Ca2+ sensor applications due to minimal functional perturbation.
• This study provides a framework for validating the biocompatibility of nanodevices for Ca2+ sensor-based biomedical applications.