Reconsideration of sedimentation equilibrium distributions reflecting the effects of small inert cosolutes on the dimerization of α-chymotrypsin

A reported discrepancy between quantitative estimates of the extent of enhanced a-chymotrypsin dimerization in the presence of sucrose is traced to different consequences of using an incorrect value of the buoyant molecular weight in the analysis of sedimentation equilibrium distributions. Support is thereby provided for the earlier contention that the effect of sucrose, as well as of glucose and raffinose, on dimerization may be rationalized quantitatively in terms of molecular crowding by an inert cosolute. (C) 2007 Elsevier B.V. All rights reserved.