Current Microbiology

, Volume 20, Issue 2, pp 111-114

First online:

Structural requirements for the induction and inhibition of 2,3-dihydroxybenzoic acid decarboxylase ofAspergillus niger

  • Ajith V. KamathAffiliated withDepartment of Biochemistry, Indian Institute of Science
  • , C. S. VaidyanathanAffiliated withDepartment of Biochemistry, Indian Institute of Science

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


2,3-Dihydroxybenzoic acid decarboxylase inAspergillus niger was induced by many substrate analogs including salicylate and gentisate. Catechol, which is the product, induced the enzyme tenfold. The purified enzyme was competitively inhibited by manyortho substituted benzoic acids. The Ki values for salicylate,o-fluoro ando-chloro benzoic acids were 0.12 mM, 0.12 mM, and 0.13 mM respectively; these values were lower than the Km value for the substrate. As the size of the group in theortho position increased, as in the case of bromo- and iodo-derivatives, there was an increase in their Ki values. The C-2 hydroxyl group was essential both for the induction and for interaction with the enzyme. The C-3 hydroxyl group was not necessary for induction or inhibition, but it might be essential for the catalysis.