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The role of thiols and disulfides in platelet function
1Department of Medicine Division of Hematology, The University of Texas Health Science Center at San Antonio, 78229, USA. essex@uthscsa.edu
Antioxidants & Redox Signaling
|July 10, 2004
Summary
Thiol-disulfide reactions involving protein disulfide isomerase are crucial for platelet function, including aggregation and adhesion. These redox-sensitive reactions impact key platelet receptors like alphaIIbbeta3 and P2Y12.
Area of Science:
- Biochemistry
- Cell Biology
- Hematology
Background:
- Disulfide bonds are vital for protein structure and stability, primarily formed in the endoplasmic reticulum.
- Emerging research highlights the dynamic role of thiol-disulfide reactions and disulfide bond rearrangement in cellular functions, particularly platelet activity.
Purpose of the Study:
- To provide an overview of recent developments in the role of thiol-disulfide reactions in platelet function.
- To focus on the involvement of protein disulfide isomerase and sulfhydryls in platelet activation and adhesion.
Main Methods:
- Investigated the presence and function of protein disulfide isomerase on the platelet surface.
- Examined the role of sulfhydryl groups in the alphaIIbbeta3 integrin activation.
- Utilized phenylarsine oxide to probe vicinal thiols in alphaIIbbeta3, assessing their redox sensitivity.
Main Results:
- Protein disulfide isomerase is present on platelets and influences aggregation, secretion, and alphaIIbbeta3 integrin activation.
- Sulfhydryl groups in alphaIIbbeta3 are critical for its activation and are potentiated by reduced glutathione.
- Redox-sensitive vicinal thiols in alphaIIbbeta3 respond to reducing equivalents; protein disulfide isomerase and sulfhydryls also impact alpha2beta1 collagen receptor-mediated adhesion and P2Y12 ADP receptor activation.
Conclusions:
- Thiol-disulfide reactions and protein disulfide isomerase play significant, dynamic roles in multiple platelet functions.
- Redox modulation of platelet receptors is a key mechanism in platelet activation and adhesion.
- A working model is proposed to explain these redox-dependent platelet processes.
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