Molecular weight of Escherichia coli β-galactosidase in concentrated solutions of guanidine hydrochloride
- 1 November 1970
- journal article
- Published by Portland Press Ltd. in Biochemical Journal
- Vol. 120 (2) , 255-261
- https://doi.org/10.1042/bj1200255
Abstract
The molecular weight of Escherichia coli β-galactosidase was determined in 6m- and 8m-guanidine hydrochloride by meniscus-depletion sedimentation equilibrium, sedimentation velocity and viscosity. Sedimentation equilibrium revealed heterogeneity with the smallest component having a molecular weight of about 50000. At lower speeds, the apparent weight-average molecular weight is about 80000. By use of a calculation based on an empirical correlation for proteins that are random coils in 6m-guanidine hydrochloride, sedimentation velocity gave a molecular weight of 91000, and the intrinsic viscosity indicated a viscosity-average molecular weight of 84000. Heating in 6m-guanidine hydrochloride lowered the viscosity of β-galactosidase in a variable manner.Keywords
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