seqinr (version 1.0-1)

computePI: To Compute the Theoretical Isoelectric Point

Description

This function calculates the theoretical isoelectric point of a protein. Isoelectric point is the pH at which the protein has a neutral charge. These estimate does not account for the post-translational modifications.

Usage

computePI(seq)

Arguments

seq

AA sequence as a vector of chars

Value

• It returns the pI.

References

The algorithm is quite the same as the one which is implemented at the following url: http://www.expasy.org/tools/pi_tool-doc.html To have an overview of the seqinR's functionnality, please consult this vignette: Charif, D., Lobry, J.R. (2005) SeqinR: a contributed package to the R project for statistical computing devoted to biological sequences retrieval and analysis. Springer Verlag, Biological and Medical Physics/Biomedical Series, in preparation.

See Also

SEQINR.UTIL

Examples

ss = read.fasta(File=system.file("sequences/seqAA.fasta",package = "seqinr"),seqtype="AA")
computePI(ss[[1]])