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Modifying the protein to crystallize better: Difference between revisions
Modifying the protein to crystallize better (edit)
Revision as of 02:19, 9 March 2008
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Several methods are available: | Several methods are available: | ||
1. Modification of lysine residues | 2.1. Modification of lysine residues | ||
This method, pioneered by the Rayment laboratory, involves the methylation -- under reducing conditions -- of lysine residues. This increases the hydrophobicity of the modified lysine sidechains, reduces the overall solubility of the protein, and -- for some proteins -- promotes the formation of ordered crystal contacts. | This method, pioneered by the Rayment laboratory, involves the methylation -- under reducing conditions -- of lysine residues. This increases the hydrophobicity of the modified lysine sidechains, reduces the overall solubility of the protein, and -- for some proteins -- promotes the formation of ordered crystal contacts. | ||
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2. Modification of cyteine residues | 2.2. Modification of cyteine residues | ||
This method involves the carboxymethylation -- under reducing conditions -- of single cysteine residues. This effectively neutralizes the cysteine residues (some of which are chemically reactive), | This method involves the carboxymethylation -- under reducing conditions -- of single cysteine residues. This effectively neutralizes the cysteine residues (some of which are chemically reactive), increases the overall solubility of the protein and can help prevent aggregation and denaturation problems. | ||
References: | References: | ||
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Eiler S et al. (2001) Protein Expr Purif. 22(2):165-73 | Eiler S et al. (2001) Protein Expr Purif. 22(2):165-73 | ||
http://www.ionsource.com/Card/cmc/method.htm -- A protocol for | http://www.ionsource.com/Card/cmc/method.htm -- A protocol for carboxymethylation | ||