Changes

From CCP4 wiki
Jump to navigationJump to search
no edit summary
Line 13: Line 13:     
There is a webserver, called SER (Surface Entropy Reduction Prediction Server), which aims to predict sites that are most suitable for mutation designed to enhance crystallizability:
 
There is a webserver, called SER (Surface Entropy Reduction Prediction Server), which aims to predict sites that are most suitable for mutation designed to enhance crystallizability:
 +
 
http://nihserver.mbi.ucla.edu/SER/
 
http://nihserver.mbi.ucla.edu/SER/
   Line 18: Line 19:  
== [[Chemical Modification]]==
 
== [[Chemical Modification]]==
 
Another method for enhancing the crystallizability of proteins involves chemical modification of specific sidechains.
 
Another method for enhancing the crystallizability of proteins involves chemical modification of specific sidechains.
   
Several methods are available:
 
Several methods are available:
    
1. Modification of lysine residues
 
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.  
 
A recent study (Walter et al. [2006] "Lysine Methylation as a Routine Rescue Strategy for Protein Crystallization" Structure 14:1617–1622) demonstrated that, out of 10 non-crystallizable proteins,  
 
A recent study (Walter et al. [2006] "Lysine Methylation as a Routine Rescue Strategy for Protein Crystallization" Structure 14:1617–1622) demonstrated that, out of 10 non-crystallizable proteins,  
 
4 proteins became crystallisable after reductive methylation.
 
4 proteins became crystallisable after reductive methylation.
 +
 +
    
2. Modification of cyteine residues  
 
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), increase the overall solubility of proteins and can help prevent aggregation and denaturation problems of proteins.
 
This method involves the carboxymethylation -- under reducing conditions -- of single cysteine residues. This effectively neutralizes the cysteine residues (some of which are chemically reactive), increase the overall solubility of proteins and can help prevent aggregation and denaturation problems of proteins.
 +
 
References:
 
References:
 +
 
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 carbocymethylation
 
http://www.ionsource.com/Card/cmc/method.htm  -- A protocol for carbocymethylation
7

edits

Cookies help us deliver our services. By using our services, you agree to our use of cookies.

Navigation menu