This PIPSA service is provided for the
comparison of the electrostatic interaction properties of proteins.
It permits the classification of proteins according to their interaction properties.
PIPSA may assist in function assignment, the estimation of binding properties and
enzyme kinetic parameters. See References
You may also download the original PIPSA code, including a python wrapper called multipipsa.
This allows to run PIPSA analysis on multiple sites of the protein and also provides comparative analysis of the binding properties of
user-defined groups of proteins. See also the references page.
To perform PIPSA on this webserver, you need to upload a set of related
protein structures in PDB format. After calculation of the protein electrostatic potentials,
the server will
calculate similarity indices for all pairs of proteins based on the electrostatic similarity.
These indices will be computed for complete protein 'skins' or for a user defined region.
The similarity indices are then converted to electrostatic 'distances'. The electrostatic
potential distance matrix is displayed in color coded form (heat map) and as a tree (epogram).
Start a PIPSA analysis (input PDB format coordinate files).
Start a PIPSA analysis (input SWISSPROT entries with EC annotation)*.
* This type of analysis involves a protein structural modelling step utilizing Modeller. Therefore this
part is subject to the Modeller license conditions.
Please obtain a Modeller license to use this service.
For apbs users, please note the changes in April 2014. Due to problems with the grid settings, calculations using apbs before April 2014 need to check if your protein is within the grid bounds.
The last installation was performed on Feb. 2010. To see the history of changes follow this link.