Classification of Coenzymes that are Confused

Coenzymes, cofactors, and activators
According to the requirements of the optimal conditions for enzyme catalyzed reactions, a certain amount of auxiliary factors should be added to the enzyme assay system in principle. Cofactors refer to non protein components required for enzyme activity, including coenzymes, cofactors, and metal ion activators. The cofactors closely bound to enzymes are called cofactors; Enzyme proteins without cofactors are called apozymes, which lack catalytic activity and require the addition of sufficient cofactors to form holoenzymes. After incubating with the cofactor for a period of time, the enzyme activity will recover. Therefore, it is often necessary to pre incubate the cofactor in the sample and reagent. The amount of auxiliary base used is often relatively small.
Coenzymes, which bind loosely to enzyme proteins and can be easily separated from enzymes through dialysis and other methods, are called coenzymes. Although coenzymes are different from enzyme substrates, they act similarly to substrates, binding, separating, and cycling with enzymes during enzymatic reactions. The determination of coenzyme dosage can be done by treating them as substrates. For example, coenzymes in lactate dehydrogenase are calculated according to the dual substrate kinetic equation.
The chemical essence of an activator is a metal ion, which can be the active center of an enzyme or activate its activity through other mechanisms. As activators, metal ions have a more complex impact on the kinetics of enzymatic reactions. The most common are divalent metal ions such as Mg2+, Zn2+, Mn2+, Ca2+, Fe2+, etc. Most heavy metal ions are denaturing agents for enzymes. Metal ions often exhibit mutual antagonism or inhibition. EDTA is often added to enzyme assay systems to chelate some non essential ions. An appropriate concentration of metal ions is necessary, as excessive ions often inhibit the rate of enzyme reactions. Due to the fact that the kinetics of activators are often different from those of enzymes, this can explain the different ratios of samples to reaction solutions, resulting in disproportionate enzyme activity measurement results. The activation effect of N-acetylcysteine on creatine kinase is similar. The dosage of activator is generally determined through repeated experiments.