Combining thermostable mutations increases the stability of lambda repressor.

R S Stearman; A D Frankel; E Freire; B S Liu; C O Pabo

doi:10.1021/bi00419a059

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Combining thermostable mutations increases the stability of lambda repressor.

R S Stearman·A D Frankel·E Freire·B S Liu·C O Pabo

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Abstract

We have combined three mutations previously shown to stabilize lambda repressor against thermal denaturation. Two of these mutations are in helix 3, where Gly-46 and Gly-48 have been replaced by alanines [Hecht, M. H., et al. (1986) Proteins: Struct., Funct., Genet. 1, 43-46]. The other mutation, which replaces Tyr-88 with cysteine, allows the protein to form an intersubunit disulfide bond [Sauer, R. T., et al. (1986) Biochemistry 25, 5992-5998]. Calorimetric measurements show that the two alanine substitutions stabilize repressor by about 8 degrees C, that the disulfide bond stabilizes repressor by about 8 degrees C, and that the triple mutant is 16 degrees C more stable than wild-type repressor.

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Amino Acid Sequence Base Sequence Calorimetry, Differential Scanning DNA-Binding Proteins Drug Stability Escherichia coli Hot Temperature Molecular Sequence Data Mutation Protein Denaturation Repressor Proteins Thermodynamics Transcription Factors Viral Proteins Viral Regulatory and Accessory Proteins Journal Article Research Support, Non-U.S. Gov't Research Support, U.S. Gov't, Non-P.H.S.Research Support, U.S. Gov't, P.H.S.

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R S Stearman, A D Frankel, E Freire, B S Liu, C O Pabo. 1988-09-20. Combining thermostable mutations increases the stability of lambda repressor.. https://doi.org/10.1021/bi00419a059

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