Prot pi[prɑːt paɪ] | Protein Tool

Prot pi | Protein Tool calculates isoelectric point and net charge of proteins, as well as the exact mass and the absorption coefficient using the amino acid sequence.

Subunits 1

Isoelectric point, mass and retention time of proteins are affected by covalent modifications. This section enables the selection of different predefined modifications as well as the definition of multiple user-defined modifications by selecting the "custom"-option. Just select a modification and click "Add Modification"-button. In the new window, detailed parameters can be defined.

please note: All parameters were calculated assuming all cysteine side chains are reduced to sulfhydryl groups. Please specify disulfide bonds by adding a modification.

Modification Complete Amino acid Location Subunit  

In this section you can specify advanced parameters for calculations. If you are not familiar with these parameters, you don't have to worry about it. The default settings are certainly correct.

Advanced parameters for calculation of isoelectric point

Calculate the charge of the protein at a defined pH.
Select the data source of pKa values for calculation of isoelectric point.

Mass calculation

Specify the resolution or the type of mass spectrometer. The resolution is defined as:
Resolution = (m/z)/∆(m/z)
∆(m/z) = FWHM


Coming Soon

Some further features.