What happens with a straightforward protein assay?
Are substances with colored or fluorescent products have been developed for this purpose?
If such a substance or product has no fluorescence available for the enzyme being assayed, what can be done and used to detect it? What is the reaction called?
The rate of the product formation is proportional to the amount of enzyme present, in other words, the enzymes catalyze reactions with readily detected products.
Use another enzyme to convert the product of the enzymatic reaction that has the fluorescence, coupled enzymatic reaction.