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Protein denaturation induced by cyclic silicone
L Sun1, H Alexander, N Lattarulo
1Department of Bioengineering, Hospital for Joint Diseases, Orthopaedic Institute, New York, NY 10003, USA.
Biomaterials
|June 5, 1998
Summary
Octamethylcyclotetrasiloxane (D4) causes protein denaturation and conformational changes in fibronectin and fibrinogen in vitro. This may explain how silicones can trigger an immune response, potentially leading to autoimmune diseases.
Area of Science:
- Biochemistry
- Immunology
- Materials Science
Background:
- Low-molecular-weight cyclic silicones, such as octamethylcyclotetrasiloxane (D4), are known to have adjuvant activity.
- The precise mechanism by which silicones elicit an immunological response remains unclear.
Purpose of the Study:
- To investigate the in vitro effects of D4 on protein structure.
- To explore the potential link between D4-induced protein changes and autoimmune responses.
Main Methods:
- Utilized fluorescence spectroscopy to detect changes in protein fluorescence intensity and wavelength shifts.
- Employed circular dichroism (CD) spectroscopy to assess alterations in protein secondary and tertiary structures.
- Incubated fibronectin (Fn) and fibrinogen (Fbg) with D4 at varying concentrations and durations.
Main Results:
- D4 induced significant denaturation and aggregation of Fn and Fbg, evidenced by protein precipitation.
- Fluorescence spectroscopy revealed decreased intensity and red-shifted emission maxima, indicating protein unfolding.
- CD spectral analysis confirmed conformational changes in the proteins upon exposure to D4.
Conclusions:
- D4 directly causes denaturation and conformational alterations in key proteins like Fn and Fbg.
- These D4-induced protein modifications may function as neoantigens, stimulating an immune response.
- The findings suggest a potential pathway for silicone-induced autoimmunity.
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