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Influence of Crowding Agents on the Small GTPase Rab2B: Stability Consideration and Intermediate Formation
Jyoti Rani Nath1, Zahoor Ahmad Parray1, Pramit K Chowdhury1
1Department of Chemistry, Indian Institute of Technology Delhi, New Delhi 110016, India.
The Journal of Physical Chemistry. B
|August 15, 2025
Summary
Macromolecular crowding affects Rab2B protein stability and conformation. Crowders like PEG and Ficoll influence thermal and chemical denaturation, potentially aiding Rab2B
Area of Science:
- Biochemistry and Molecular Biology
- Cell Biology
Background:
- Rab2B is vital for vesicle trafficking and Golgi morphology.
- Protein stability and conformation are influenced by cellular environments.
Purpose of the Study:
- To investigate the effects of macromolecular crowding on Rab2B denaturation.
- To understand how crowders (PEG 8, Ficoll 70) and urea impact Rab2B stability and structure.
Main Methods:
- Thermal and chemical denaturation assays.
- Circular dichroism (CD) and fluorescence spectroscopy.
- ANS fluorescence and time-resolved fluorescence studies.
Main Results:
- Increasing urea concentrations decreased Rab2B stability in a crowder-dependent manner.
- Crowders induced a distinct intermediate with greater structural content in 2 M urea.
- Changes in protein hydrophobicity and tryptophan residue accessibility were observed.
Conclusions:
- Macromolecular crowding significantly impacts Rab2B stability and conformation.
- Crowding may facilitate Rab2B's functional conformational changes in vivo.
- Findings enhance understanding of protein behavior in crowded biological environments.
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