TY - JOUR T1 - Inhibition of Catalase Activity in Wines JF - American Journal of Enology and Viticulture JO - Am J Enol Vitic. SP - 92 LP - 96 DO - 10.5344/ajev.1975.26.2.92 VL - 26 IS - 2 AU - D. Temple AU - C. S. Ough Y1 - 1975/01/01 UR - http://www.ajevonline.org/content/26/2/92.abstract N2 - Catalase (fungal source) was found to be essentially completely inhibited by wine concentrations of ethanol. The inhibition is noncompetitive and apparently involves the binding of the ethanol with the enzyme in the compound I form, thereby inhibiting the catalatic reaction. The peroxidatic reaction then is either extremely slow, or does not proceed to form acetaldehyde, but removes the enzyme from further catalatic reactions. The Km of the reaction (H2O2→ H2O + ½ O2) is 0.02 M and Vmax was 2.2 x 103 µ moles/min. Malic acid, grape seed tannin, catechol, chlorogenic acid and gallic acid did not affect catalase activity. The ethanol concentration in wine accounts for essentially all the inhibition found. ER -