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Updated: Jun 26, 2026
10:02
Submillisecond Conformational Changes in Proteins Resolved by Photothermal Beam Deflection
Published on: February 18, 2014
Photothermal Conversion and Temperature Elevation by a Minimal Heme Protein
Shima Ooto1, Haruto Ishikawa1, Taito Urui1
1Department of Chemistry, Graduate School of Science, The University of Osaka, 1-1 Machikaneyama, Toyonaka, Osaka 560-0043, Japan.
The Journal of Physical Chemistry. B
|June 25, 2026
Summary
Researchers developed a novel molecular heater using cytochrome b5 (HaCytb5) for precise intracellular heating. This biocompatible protein efficiently converts light to heat, enabling localized temperature control for cellular studies.
Area of Science:
- Cellular biology
- Biophysics
- Biochemistry
Background:
- Heat is vital for biological processes, acting as an energy source and signaling molecule.
- Current tools for precise intracellular heating are limited, hindering cellular thermobiology research.
- Developing biocompatible molecular heaters for localized photothermal conversion is crucial.
Purpose of the Study:
- To investigate the photothermal conversion ability of cytochrome b5 from Hadesarchaea archaeon YNP_N21 (HaCytb5).
- To assess HaCytb5 as a potential tool for localized intracellular heating.
- To evaluate the impact of modifications like His-tagging on HaCytb5's function.
Main Methods:
- Monitoring temperature changes in aqueous solutions using Raman spectroscopy under 532 nm laser irradiation.
- Investigating the thermal stability of HaCytb5.
- Employing thermal diffusion modeling to analyze heat distribution.
Main Results:
- HaCytb5 demonstrated significant photothermal conversion, inducing temperature increases up to 7.0 K.
- The protein exhibited exceptional thermal stability, partly due to a covalent heme-polypeptide linkage.
- His-tagging did not compromise HaCytb5's thermal stability or heating efficiency.
Conclusions:
- HaCytb5 is a potent, minimally perturbative thermogenic agent.
- It serves as a promising nanoscale tool for localized intracellular heating.
- HaCytb5 facilitates the investigation of temperature heterogeneity within living cells.
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