[EMBOSS] iep program for multiple protein sequences - Checked by

Guy Bottu gbottu at ben.vub.ac.be
Fri Sep 8 07:46:32 UTC 2006

On Thu, Sep 07, 2006 at 06:27:22PM -0400, Tao Song wrote:
> I wonder can the iep program  that calculates the isoelectric point of 
> a protein be used
> for a protein database?

Yes, iep can take multiple proteins as input. It will create an output 
file with the titration curves of the different proteins the one after 
the other. It does not make one graph for all the proteins together, 
which would anyway not make much biological sence.

> When asked to input protein sequence I gave 'tsw' 
> instead of
> 'tsw:laci_ecoli' I got an error that said 'sequence must be protein sequence 
> without BZ U X
> or *: found bad character Z'. Does iep can only take one protein sequence as 
> input file?

The problem here is that iep takes as input only a protein sequence 
without ambiguity symbols. The reason is without doubt that it is not 
clear whether B should be handled as a Asp (negative) or a Asn (neutral), 

	Guy Bottu,
	Belgian EMBnet Node

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