6.3.2 Inhibit enzyme activity
Metal ions and chelation can inhibit different steps of enzyme catalyzed redox reaction. For instance, Ethylenediaminetetraacetic acid (EDTA) can inhibit hexokinase activity and reduce the formation of glucose-6-P. Cu2+, Zn2+, Hg2+and Co2+ can inhibit Trx activity. Aurothioglucose (ATG) and aurothiomalate (ATM) can inhibit TrxR activity (Kao et al., 2010). Inhibitors can be introduced at earlier manufacture steps, such as cell culture media or HCCF (before and after filtration) with the final concentration of inhibitors are at micro-molar to milli-molar levels. Previous research showed that if the inhibitor efficiency is high, it can completely inhibit disulfide bond reduction during 2-3 days HCCF storage time (Trexler-Schmidt et al., 2010). However, studies on the inhibitor performances when HCCF storage time is longer were limited and may need further investigation.