[Biojava-l] Problem With Isoelectric point

[george waldon]

Yasset,

Your are right; you should always get a pI value when both peptide ends are free. It probably comes from the binary search; I'll have a look into this.

Thanks for reporting this,
George

-----Original Message-----
From: biojava-l-bounces at lists.open-bio.org [mailto:biojava-l-bounces at lists.open-bio.org] On Behalf Of yasset perez riverol
Sent: Wednesday, August 22, 2007 6:28 PM
To: biojava-l at lists.open-bio.org
Subject: [Biojava-l] Problem With Isoelectric point

 Hi, 
 I have a problem when I execute the Isoelectrc
 Point calculation for this peptides:
    ALLIDLPV
    FDIYAGTPV
    SVLLMSAEI
    PTGDTTGYLANPEEV
 I all the case I receive this error :
    Error, the peptide probably contains only positive
or negative charges.
 
Well I try to calculate the isoelectric Point for
all the peptides with de Expasy Calculator and I
obtained:
       ALLIDLPV: 
          Theoretical pI: 3.80
          Molecular weight (average): 853.07 
       FDIYAGTPV: 
          Theoretical pI: 3.80
          Molecular weight (average): 982.10 
       SVLLMSAEI: 
          Theoretical pI: 4.00
          Molecular weight (average): 962.17 
       PTGDTTGYLANPEEV: 
          Theoretical pI: 3.57
          Molecular weight (average): 1563.64
 
 My code is this:
   OBioSeq = ProteinTools.createProtein(Sequence);
   IsoelectricPointCalc OBioIsoc = new
  IsoelectricPointCalc();
   double dIsoelec = 0.0;
   dIsoelec = OBioIsoc.getPI(OBioSeq,true,true);
   
 Thanks in advance
 Center of Molecular Biology.
 Havana University
 Cuba.


__________________________________________________
Correo Yahoo!
Espacio para todos tus mensajes, antivirus y antispam ¡gratis! 
Regístrate ya - http://correo.espanol.yahoo.com/ 
_______________________________________________
Biojava-l mailing list  -  Biojava-l at lists.open-bio.org
http://lists.open-bio.org/mailman/listinfo/biojava-l