High-resolution nuclear magnetic resonance studies of the lac repressor. 3. Unfolding of the lac repressor headpiece
- 17 February 1981
- journal article
- research article
- Published by American Chemical Society (ACS) in Biochemistry
- Vol. 20 (4) , 829-833
- https://doi.org/10.1021/bi00507a027
Abstract
At temperatures below 20.degree. C, the lac repressor headpiece (N-terminal amino acids 1-51) of Escherichia coli has a well-defined structure independent of ionic strength. Its unfolding with increasing temperature proceeds gradually with a characteristic transition temperature which depends on ionic strength. Unfolding was studied by NMR and CD (circular dichroism). Shifts of several methyl and all tyrosyl resonances can be followed, allowing a detailed analysis of the temperature denaturation. At high ionic strength (1 M), the unfolding is complete at 85.degree. C; at low ionic strength (0.01 M), it is complete by 65.degree. C. Native and partially unfolded structures are in rapid exchange during the unfolding and the process appears completely reversible at all ionic strengths.This publication has 5 references indexed in Scilit:
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