Many enzymes are inhibited irreversibly by heavy metal ions such as Hg2+ , Cu2+ , or Ag+ , which can react with essential sulfhydryl groups to form mercaptides. Enz−SH+Ag+⟶Enz−S−Ag+H+ The affinity of Ag+ for sulfhydryl groups is so great that Ag+ can be used to titrate −SH groups quantitatively. To 10.0 mL of a solution containing 3.4 mg/mL of a pure enzyme, an investigator added just enough AgNO3 to completely inactivate the enzyme. A total of 0.134 μmol AgNO3 was required. Calculate the minimum molecular weight (r) of the enzyme.