[Biojava-l] InstabilityIndex

[Steve Darnell]

@Subrata, The class does not handle characters other than the standard 20 amino acids. We substitute BJOUXZ with DLKCAE and live with the approximation.

@Ah Fu, In the past we have used average values for B (D or N), J (L or I), and Z (E or Q), and a dummy substitution for X (G or A). Our U and O substitutions just map to the closest natural amino acid. It would be nice if real values existed for selenocysteine and pyrrolysine, but I haven't a clue if they do.

@Andreas, I would suggest that a general policy that all protein sequence analyses support the 6 non-standard letter would be a good thing. A nice ideal, but who has the time? :)

Regards,
Steve

-----Original Message-----
From: biojava-l-bounces at lists.open-bio.org [mailto:biojava-l-bounces at lists.open-bio.org] On Behalf Of Andreas Prlic
Sent: Monday, October 08, 2012 5:44 PM
To: subrata sinha
Cc: Chuan Hock Koh; biojava-l at biojava.org
Subject: Re: [Biojava-l] InstabilityIndex

Hi Subrata,

Please don't mail me directly, but send your questions to the list.
Chances are that somebody there can help you best.

Ah Fu, do you have any thoughts on this?

Thanks,

Andreas




On Mon, Oct 8, 2012 at 12:06 PM, subrata sinha <subratasinha2006 at yahoo.co.in> wrote:
> Dear Sir,
>
> I was testing the getInstabilityIndex() method of 
> org.biojava3.aaproperties.PeptideProperties class.
>
> I am trying to find InstabilityIndex for very short segment of 
> peptide, as short as two. But I am getting some surprising result in 
> negative.Then i found that the method perhaps giving -ve result for 
> ambiguous characters. So how to handle a situation if my protein 
> sequence contains ambiguous characters
>
> Input Sequence            Instability Index
>
> GTDG                      -13.725
> VDVR                      -30.075
>
> How i analyse the above situation.
>
> Kindly help me.
>
>
> With Regards
>
> Subrata Sinha
> Assistant Professor
> Centre for Bioinformatics Studies
> Dibrugarh University
_______________________________________________
Biojava-l mailing list  -  Biojava-l at lists.open-bio.org http://lists.open-bio.org/mailman/listinfo/biojava-l