Carbonic anhydrase catalysed hydrolysis of fluorogenic esterase substrates

Carbonic anhydrases from spinach leaves, Chlamydomonas reinhardtii and bovine erythrocytes were examined for their ability to hydrolyse the fluorogenic esterase substrates 7‐acetoxy‐4‐methylcoumarin, 7‐acetoxycoumarin‐3‐carboxylic acid and fluorescein diacetate. The spinach enzyme was unable to hydrolyse any of the three substrates, however, the C. reinhardtii enzyme hydrolysed 7‐acetoxy‐4‐methylcoumarin and fluorescein diacetate, but at a much slower rate than the bovine erythrocyte enzyme which hydrolysed all three substrates. A method was developed to assay purified carbonic anhydrase from C. reinhardtii based on the enzyme‐catalysed hydrolysis of fluorescein diacetate.