Dimerization of Thermomonospora fusca .beta.-1,4-endoglucanase E2
- 1 August 1993
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 32 (32) , 8146-8150
- https://doi.org/10.1021/bi00083a013
Abstract
Unboiled Thermomonospora fusca endoglucanase E2 electrophoresed on SDS-polyacrylamide gels migrated in the range of 80-90 kDa, but when boiled it migrated in the 40-42-kDa range. Sedimentation equilibrium centrifugation as well as chemical cross-linking experiments confirmed that E2 is a dimer. The dimer was reversibly dissociated at low pH. The E2 dimer was stable up to 70 degrees C, but began to dissociate at this temperature after a 30-60-min incubation. A nondimerizing mutant was obtained using region-specific chemical mutagenesis. DNA sequencing of this mutant revealed a single base change that substituted Gly for Glu-263. Chemical modification of carboxylic acid residues in E2 disrupted the dimer interaction.Keywords
This publication has 0 references indexed in Scilit: