Interaction of pyridoxal phosphate with the amino groups at the active site of 5-aminolevulinic acid dehydratase in maize.

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Date
1985-06
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Abstract
Pyridoxal 5'-phosphate strongly and reversibly inhibited maize leaf 5-amino levulinic acid dehydratase. The inhibition was linearly competitive with respect to the substrate 5-aminolevulinic acid at pH values between 7 to 9ยท0. Pyridoxal was also effective as an inhibitor of the enzyme but pyridoxamine phosphate was not inhibitory. The results suggest that pyridoxal 5'-phosphate may be interacting with the enzyme either close to or at the 5- aminolevulinic acid binding site. This conclusion was further corroborated by the detection of a Schiff base between the enzyme and the substrate, 5-aminolevulinic acid and by reduction of pyridoxal phosphate and substrate complexes with sodium borohydride.
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Keywords
Dehydratase, pyridoxal 5'-phosphate, aminogroups, Zea mays
Citation
Maralihalli G B, Bhagwat A S. Interaction of pyridoxal phosphate with the amino groups at the active site of 5-aminolevulinic acid dehydratase in maize. Journal of Biosciences. 1985 Jun; 7(3&4): 359-364.