Myo-inositol oxygenase from oat seedlings

Area of Science:

• Biochemistry
• Enzymology
• Plant Science

Background:

• Oat seedlings possess enzyme preparations with myo-inositol oxygenase activity.
• Previous preparations showed less specificity compared to sources like rat kidney or yeast.
• This suggested the presence of multiple enzymes or a less specific oat myo-inositol oxygenase.

Purpose of the Study:

• To purify the myo-inositol oxygenase from oat seedlings.
• To determine the specificity of the purified oat enzyme.
• To differentiate myo-inositol oxygenase from other related enzymes in oat extracts.

Main Methods:

• Affinity gel chromatography using a myo-inositol specific gel.
• Enzyme purification and characterization.
• Elution with increasing concentrations of myo-inositol to separate enzymes.

Main Results:

• A homogeneous preparation of myo-inositol oxygenase was obtained.
• The purified oat enzyme exhibited strict specificity, similar to myo-inositol oxygenase from other sources.
• Other inositols and inositol methyl ether activity was attributed to separate enzymes separable by affinity chromatography.
• The purified enzyme has a molecular weight of 62,000 and forms oligomers at physiological pH.

Conclusions:

• Oat seedlings contain a highly specific myo-inositol oxygenase.
• The broader activity observed in initial preparations was due to other enzymes.
• Affinity chromatography is effective for purifying specific enzymes and separating them from related activities.