Purification and characterization of UV-B induced phenylalanine ammonia- lyase from rice seedlings
Purification and characterization of UV-B induced phenylalanine ammonia- lyase from rice seedlings
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Date
1999-03-10
Authors
Sarma, Annamraju D.
Sharma, Rameshwar
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Abstract
On exposure of rice seedlings to UV-B radiations, a four fold induction of PAL activity was observed. Purification of induced PAL revealed the presence of a single isoform with a molecular mass 320 kD and a subunit Mr of 84 kD. The enzyme exhibited Michaelis-Menten kinetics with a Km of 500 μM, optimal pH 8.9 and an activation energy 1.9 kcal. The induced enzyme was sensitive to inhibition by phenylpropanoid intermediates involved in flavonol and anthocyanin biosynthetic pathway.
Description
Keywords
Gramineae,
Oryza sativa,
Phenylalanine ammonia-lyase,
Rice,
UV-B radiation
Citation
Phytochemistry. v.50(5)