computePI {seqinr} | R Documentation |
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.
computePI(seq)
seq |
AA sequence as a vector of chars |
It returns the pI.
Protein pI is calculated using pK values of amino acids described in Bjellqvist et al. See also SEQINR.UTIL
for more details.
D. Charif
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.
ss = read.fasta(File=system.file("sequences/seqAA.fasta",package = "seqinr"),seqtype="AA") computePI(ss[[1]])