Starch phosphorylase inhibitor from sweet potato
1Department of Argicultural Chemistry, National Taiwan University, 1 Roosevelt Road Section 4, Taipei 107, Republic of China.
Plant Physiology
|February 1, 1986
Summary
A novel starch phosphorylase inhibitor was isolated from sweet potato roots. This protein is widely found in plants and may regulate plant enzyme activity.
Area of Science:
- Plant biochemistry
- Enzyme regulation
- Protein purification
Background:
- Starch phosphorylase plays a role in plant carbohydrate metabolism.
- Understanding enzyme regulation is crucial for plant science.
Purpose of the Study:
- To purify and characterize a starch phosphorylase inhibitor from sweet potato.
- To investigate the inhibitor's properties and its potential role in vivo.
Main Methods:
- Protein purification from sweet potato root.
- Enzyme inhibition assays.
- Immunofluorescence techniques.
Main Results:
- A noncompetitive starch phosphorylase inhibitor (250,000 MW, 5 subunits, pI 4.63) was purified.
- The inhibitor showed cross-reactivity in potato, spinach, and rice, suggesting universal occurrence in plants.
- Immunofluorescence localized the inhibitor and phosphorylase within amyloplasts and cell walls.
Conclusions:
- The sweet potato starch phosphorylase inhibitor is widely distributed in higher plants.
- The co-localization of inhibitor and enzyme suggests an in vivo regulatory role.
- This protein may play a significant, yet unknown, role in plant enzyme regulation.
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