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Polygalacturonases Release Cell-Wall-bound Proteins
L L Strand1, C Rechtoris, H Mussell
1Boyce Thompson Institute, Yonkers, New York 10701.
Plant Physiology
|December 1, 1976
Summary
Fungal polygalacturonases release plant cell wall proteins, including those with peroxidase activity and hydroxyproline. Cellulase showed no effect, but inhibiting polygalacturonase stopped protein release, confirming its role.
Area of Science:
- Plant biochemistry
- Enzymology
- Fungal biology
Background:
- Plant cell walls are complex structures.
- Enzymes play roles in cell wall modification.
- Fungal enzymes are potential tools for studying plant cell walls.
Purpose of the Study:
- To investigate the role of fungal polygalacturonases in releasing proteins from plant cell walls.
- To characterize the proteins released by enzymatic treatment.
- To determine the specificity of enzyme action on cell wall components.
Main Methods:
- Purification of polygalacturonases from fungal sources.
- Preparation of cell wall fractions from three plant species.
- Enzymatic digestion assays using purified enzymes.
- Analysis of released proteins for enzymatic activity (peroxidase) and composition (hydroxyproline).
- Enzyme inhibition assays to confirm specificity.
Main Results:
- Purified polygalacturonases released proteins from plant cell wall fractions.
- Released proteins exhibited peroxidase activity.
- Hydroxyproline was detected in several protein fractions.
- Cellulase, devoid of pectic enzyme activity, did not release proteins.
- Specific inhibition of endopolygalacturonase activity abolished protein release.
Conclusions:
- Fungal polygalacturonases are effective in releasing proteins from plant cell walls.
- The released proteins may be involved in cell wall structure or modification.
- Endopolygalacturonase activity is specifically responsible for the release of these proteins.
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