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Prosaposin is a novel coenzyme Q10-binding protein
Makoto Hasegawa1, Yorihiro Yamamoto1, Akio Fujisawa1
1School of Bionics, Tokyo University of Technology, 1404-1 Katakura-machi, Hachioji, Tokyo 192-0982, Japan.
Journal of Clinical Biochemistry and Nutrition
|March 21, 2024
Summary
Prosaposin, a protein precursor, binds Coenzyme Q10 (CoQ10), an essential molecule for energy production and antioxidant defense. This binding occurs in human cells and body fluids, suggesting a novel role for prosaposin in CoQ10 transport and function.
Area of Science:
- Biochemistry
- Molecular Biology
- Cell Biology
Background:
- Coenzyme Q10 (CoQ10) is vital for mitochondrial ATP production and acts as a key antioxidant.
- Its hydrophobic nature suggests the involvement of binding and transfer proteins.
- Saposin B was previously identified as a CoQ10-binding protein.
Purpose of the Study:
- To investigate whether prosaposin, the precursor of saposin B, also binds CoQ10.
- To explore the presence of prosaposin-CoQ10 complexes in various biological samples.
Main Methods:
- Isolation of prosaposin from human seminal plasma.
- Extraction of CoQ10 from hexane solution into an aqueous phase.
- Immunoprecipitation of mouse brain, liver, and kidney cytosol using anti-prosaposin antibodies.
Main Results:
- Prosaposin was confirmed to bind CoQ10.
- Prosaposin-coenzyme Q9 complexes were detected in mouse brain, liver, and kidney cytosol.
- The findings suggest prosaposin binds CoQ10 in human cells and body fluids.
Conclusions:
- Prosaposin is a CoQ10-binding protein.
- The prosaposin-CoQ10 complex may play a significant role in vivo.
- Further research is warranted to elucidate the precise functions of this complex.
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