[Artificial oligomerization of enzymes--a new way of regulating their catalytic activity in reversed micellar...

Comparative studies were carried out in the catalytic activity regulation of native alpha-chymotrypsin and its artificially produced hexameric form as an example of non-dissociating oligomeric enzyme (covalently cross-linked by means of succinimidyl-3-(2-pyridylthiopropionate] in the Aerosol OT reversed micelles in octane. Native (monomeric) alpha-chymotrypsin exhibits maximal catalytic activity in the reversed micelles at the hydration degree w0 = 10, when the radius of the micelle inner cavity is equal to the radius of the alpha-chymotrypsin globule. For the alpha-chymotrypsin hexamer, optimum is observed at w0 = 45, with the inner micellar cavity radius (r = 68 A) being approximately equal to the radius of the sphere surrounding the octahedral combination of the six monomeric alpha-chymotrypsin molecules (r = 61 A). Thus, construction of the corresponding oligomeric structures is made easy, with the optimal catalytic activity in a preset range of the hydration degrees.