84
edits
Modifying the protein to crystallize better: Difference between revisions
Jump to navigation
Jump to search
m
Modifying the protein to crystallize better (edit)
Revision as of 15:04, 13 March 2008
, 13 March 2008Use Wiki === headers, not 1. 2. ... and auto-make table of contents ...
(Editorial changes - please dont use xxx unless you want to create a page with that name!) |
m (Use Wiki === headers, not 1. 2. ... and auto-make table of contents ...) |
||
| Line 2: | Line 2: | ||
There are a number of methods which can be used to modify the crystallization behavior of proteins. | There are a number of methods which can be used to modify the crystallization behavior of proteins. | ||
=== Genetic/Mutagenesis Approach=== | |||
=== | |||
This method, also called 'surface entropy-reduction mutagenesis', involves mutation of sidechains on the surface of proteins, in order to reduce the entropic cost of forming ordered intermolecular crystal contacts and thus enhance the crystallizability of proteins. | This method, also called 'surface entropy-reduction mutagenesis', involves mutation of sidechains on the surface of proteins, in order to reduce the entropic cost of forming ordered intermolecular crystal contacts and thus enhance the crystallizability of proteins. | ||
| Line 19: | Line 13: | ||
http://nihserver.mbi.ucla.edu/SER/ | http://nihserver.mbi.ucla.edu/SER/ | ||
=== Chemical Modification=== | === Chemical Modification=== | ||
| Line 25: | Line 18: | ||
Several methods are available: | Several methods are available: | ||
====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. | ||
| Line 34: | Line 27: | ||
Here is a protocol for [[Lysine Methylation]]. | Here is a protocol for [[Lysine Methylation]]. | ||
====Modification of cysteine 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), increases the overall solubility of the protein and can help prevent aggregation and denaturation problems. | 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. | ||