In which case, it depends on the type of inhibitor. A competitive inhibitor has a structure similar to the substrate, hence would bind to the active site as well, competing with the substrate for the enzyme active sites, decreasing enzymatic activity. A non-competitive inhibitor binds to the allosteric site of the enzyme, causing a structural change in the enzyme active site shape.
There's a difference between the effects of cold-brewed coffee vs. hot-brewed coffee: because different chemical reactions are achieved at higher temperatures, cold-brewed coffee will have a smoother caffeine effect and overall less acidity, which some people experience as part of the kick..
Caffeine's solubility is primary driven by temperature, such that at higher temperatures, significantly more caffeine will dissolve in solution than at cooler temperatures, says Joseph Rivera of Coffee Chemistry. If you are using the same brew-to-water ratios, the cold brew will definitely have less caffeine than hot..