1L23

ENHANCED PROTEIN THERMOSTABILITY FROM SITE-DIRECTED MUTATIONS THAT DECREASE THE ENTROPY OF UNFOLDING

Summary for 1L23

• Entry DOI: 10.2210/pdb1l23/pdb
• Related: 1L01 1L02 1L03 1L04 1L05 1L06 1L07 1L08 1L09 1L10 1L11 1L12 1L13 1L14 1L15 1L16 1L17 1L18 1L19 1L20 1L21 1L22 1L24 1L25 1L26 1L27 1L28 1L29 1L30 1L31 1L32 1L33 1L34 1L35 1L36 2LZM
• Descriptor: T4 LYSOZYME (2 entities in total)
• Functional Keywords: hydrolase (o-glycosyl)
• Biological source: Enterobacteria phage T4
• Cellular location: Host cytoplasm : P00720
• Total number of polymer chains: 1
• Total formula weight: 18676.49

Authors

Nicholson, H.,Matthews, B.W. (deposition date: 1989-05-01, release date: 1990-01-15, Last modification date: 2024-05-22)

Primary citation

Matthews, B.W.,Nicholson, H.,Becktel, W.J.
Enhanced protein thermostability from site-directed mutations that decrease the entropy of unfolding.
Proc.Natl.Acad.Sci.USA, 84:6663-6667, 1987

PubMed Abstract: It is proposed that the stability of a protein can be increased by selected amino acid substitutions that decrease the configurational entropy of unfolding. Two such substitutions, one of the form Xaa----Pro and the other of the form Gly----Xaa, were constructed in bacteriophage T4 lysozyme at sites consistent with the known three-dimensional structure. Both substitutions stabilize the protein toward reversible and irreversible thermal denaturation at physiological pH. The substitutions have no effect on enzymatic activity. High-resolution crystallographic analysis of the proline-containing mutant protein (Ala-82----Pro) shows that its three-dimensional structure is essentially identical with the wild-type enzyme. The overall structure of the other mutant enzyme (Gly-77----Ala) is also very similar to wild-type lysozyme, although there are localized conformational adjustments in the vicinity of the altered amino acid. The combination of a number of such amino acid replacements, each of which is expected to contribute approximately 1 kcal/mol (1 cal = 4.184 J) to the free energy of folding, may provide a general strategy for substantial improvement in the stability of a protein.

PubMed: 3477797
DOI: 10.1073/pnas.84.19.6663

Experimental method

X-RAY DIFFRACTION (1.7 Å)