bio-isoelectric_point

The isoelectric point (pI), sometimes abbreviated to iep, is the pH at which a particular molecule or surface carries no net electrical charge.

This library is a ruby implementation for calculating the isoelectric point of a protein, based on the bioperl’s approach. It can be installed as a bioruby-plugin.

Support for the following Pka sets is available

* dta_select
* emboss
* rodwell
* wikipedia
* sillero

You can also create a custom Pka set as shown in the example

Installation

gem install bio-isoelectric_point

Uninstallation

gem uninstall bio-isoelectric_point

Usage

require ‘bio-isoelectric_point’

protein_seq = Bio::Sequence::AA.new(“KKGFTCGELA”)

	#what is the protein charge at ph 14?
	charge = protein_seq.calculate_charge_at(14)     #=>-2.999795857467562

	#calculate the ph using dtaselect pka set and round off to 3 decimal places
	isoelectric_point = protein_seq.calculate_iep('dtaselect', 3)   #=>8.219

# calculate the iep ph with a custom set custom_pka_set = { “N_TERMINUS” => 8.1, “K” => 10.1, “R” => 12.1, “H” => 6.4, “C_TERMINUS” => 3.15, “D” => 4.34, “E” => 4.33, “C” => 8.33, “Y” => 9.5 } iep_ph = protein_seq.calculate_iep(custom_pka_set, 3) #=> 8.193

Contributing to bio-isoelectric_point

  • Check out the latest master to make sure the feature hasn’t been implemented or the bug hasn’t been fixed yet

  • Check out the issue tracker to make sure someone already hasn’t requested it and/or contributed it

  • Fork the project

  • Start a feature/bugfix branch

  • Commit and push until you are happy

  • Make sure to add tests for it. This is important so I don’t break it in a future version unintentionally.

  • Please try not to mess with the Rakefile, version, or history. If you want to have your own version, or is otherwise necessary, that is fine, but please isolate to its own commit so I can cherry-pick around it.

Copyright © 2010 George Githinji. See LICENSE.txt for further details.