Stability of the Quaternary Structure of Butyrylcholinesterase Subjected to Ultrasound or Hydrostatic Pressure
Human butyrylcholinesterase (HuBuChE, EC 126.96.36.199) is a tetrameric enzyme arranged as a dimer of dimers linked by a disulfide bridge at the C-terminus. However, the C-terminal helical segment contains numerous residues presumably involved in the tetramerization domain (1). To evaluate the contribution of aromatic (Ar) residues to tetramerization, the stability of the enzyme tetramer was investigated by hydrostatic pressure and ultrasound techniques. Pressure and ultrasound are known to reinforce Ar-Ar interactions whereas they cause disruption of other weak interations (2).