1cx6
From Proteopedia
T4 LYSOZYME SUBSTITUTED WITH SELENOMETHIONINE
Overview
The availability of a series of phage T4 lysozymes with up to 14 methionine residues incorporated within the protein has made it possible to systematically compare the effect on protein stability of selenomethionine relative to methionine. Wild-type lysozyme contains two fully buried methionine residues plus three more on the surface. The substitution of these methionine residues with selenomethionine slightly stabilizes the protein. As more and more methionine residues are substituted into the protein, there is a progressive loss of stability. This is, however, increasingly offset in the selenomethionine variants, ultimately resulting in a differential increase in melting temperature of about 7 degrees C. This increase, corresponding to about 0.25 kcal/mol per substitution, is in reasonable agreement with the difference in the solvent transfer free energy between the two amino acids.
About this Structure
1CX6 is a Single protein structure of sequence from Enterobacteria phage t4. Full crystallographic information is available from OCA.
Reference
Substitution with selenomethionine can enhance the stability of methionine-rich proteins., Gassner NC, Baase WA, Hausrath AC, Matthews BW, J Mol Biol. 1999 Nov 19;294(1):17-20. PMID:10556025 Page seeded by OCA on Fri May 2 13:12:39 2008
