(A-3) Hence the enzyme rate equation obtains the following format: (A-4) For the purpose of our analysis, equation (A-4) can be reduced to the expression (equation (1)) of the main text: (A-5) where is the rate expression in the absence of ion metal, i.e. vo (A-6) and (A-7) Effect of Cd2+ on hexokinase and phosphofructokinase kinetic reactions The inhibition of HK and PFK by the ion metal Cd2+ is described by the mechanism displayed in Fig. 4B. and represent enzyme-metal and EXm+1 ESnXm+1 substrate-enzyme-metal complexes, with = 1 for HK and = 2 for PFK. m m The total active enzyme concentration () is given by the following expression: (A-8) As above, for any of the binding sites on a protein, the probability that it has a metal bound is given by Hence the probability that binding sites contain the Itot/Etot. m + 1 metal is: (A-9) We assume that the enzyme becomes inactive once all m+1 binding sites have Cd2+ bound. As a consequence, this leads to the expression (equation (2)) of the main text: (A-10) where is the rate expression in the absence of ion metal, i.e. vo
(A-3) Hence the enzyme rate equation obtains the following format: (A-4) For the purpose of our analysis, equation (A-4) can be reduced to the expression (equation (1)) of the main text: (A-5) where vo is the rate expression in the absence of ion metal, i.e. (A-6) and (A-7) Effect of Cd2+ on hexokinase and phosphofructokinase kinetic reactions The inhibition of HK and PFK by the ion metal Cd2+ is described by the mechanism displayed in Fig. 4B. EXm+1 and ESnXm+1 represent enzyme-metal and substrate-enzyme-metal complexes, with m = 1 for HK and m = 2 for PFK. The total active enzyme concentration () is given by the following expression: (A-8) As above, for any of the binding sites on a protein, the probability that it has a metal bound is given by Itot/Etot. Hence the probability that m + 1 binding sites contain the metal is: (A-9) We assume that the enzyme becomes inactive once all m+1 binding sites have Cd2+ bound. As a consequence, this leads to the expression (equation (2)) of the main text: (A-10) where vo is the rate expression in the absence of ion metal, i.e.