The fourth ligand on the Zn(II) ion is a water molecule. The zinc coordination is tetrahedral. The three histidine residues are sometimes referred to as first coordination sphere ligands. This set of ligands is appropriate to give the water ligand the pKa of 6.5, a value where catalysis is most efficient.
Behind Closed Doors  is a country song written by Kenny O'Dell. It was first recorded by Charlie Rich for his 1973 album Behind Closed Doors. The single was Rich's first number-one hit on the country charts, spent 20 weeks on this chart, and was also a crossover hit on the pop charts. Background vocals were provided by The Nashville Edition.
read more. Kix's biggest hit DonT close your eyes Hard rock power ballad off the gold album Blow my fuse. The Don't close Your Eyes Songfacts says: This is as soulful and meaningful a song as any hair metal band ever recorded. Not only is it an anti-suicide song with gut-wrenchingly frank lyrics, but it's delivered with tonsil-blistering intensity by the roaring banshee vocals of Steve Whiteman.