... CA, USA), zincsulfate (Caledon Laboratory Chemicals, Georgetown,Canada), ammonium formate buffer (Sigma-Aldrich,Oakville, Canada), ammonium hydroxide (BDH Chemi-cals ⁄ VWR, Mississauga, Canada), ... divided by a factor of 33. UV spectra were acquiredusing a Cary 5G UV-Vis-NIR spectrophotometer (VarianCanada, Mississauga, Canada) in a 1 cm quartz cuvette atroom temperature (22 °C) and recorded ... protein.Cd2+was added incrementally to the solution of Zn4 a to 8.2 molar equivalents, with thorough mixing after eachtitration. Mass spectra were acquired at each addition after a 2–5 min delay to allow...