Bio.SeqUtils.IsoelectricPoint module

Calculate isoelectric points of polypeptides using methods of Bjellqvist.

pK values and the methos are taken from:

* Bjellqvist, B.,Hughes, G.J., Pasquali, Ch., Paquet, N., Ravier, F.,
Sanchez, J.-Ch., Frutiger, S. & Hochstrasser, D.F.
The focusing positions of polypeptides in immobilized pH gradients can be
predicted from their amino acid sequences. Electrophoresis 1993, 14,
1023-1031.

* Bjellqvist, B., Basse, B., Olsen, E. and Celis, J.E.
Reference points for comparisons of two-dimensional maps of proteins from
different human cell types defined in a pH scale where isoelectric points
correlate with polypeptide compositions. Electrophoresis 1994, 15, 529-539.

I designed the algorithm according to a note by David L. Tabb, available at: http://fields.scripps.edu/DTASelect/20010710-pI-Algorithm.pdf

class Bio.SeqUtils.IsoelectricPoint.IsoelectricPoint(ProteinSequence, AminoAcidsContent)

Bases: object

A class with one public method to calculate the pI of a protein.

Access this class through ProtParam.ProteinAnalysis class. First make a ProteinAnalysis object and then call its isoelectric_point method.

__init__(self, ProteinSequence, AminoAcidsContent)

Initialize the class.

pi(self)

Calculate and return the isoelectric point as float.