Page 1 of 1
a problem with the modeling from I-Tasser webserver
Posted: Sun Sep 07, 2025 2:43 am
by himada97
Hi,
I have submitted a peptide of 13 amino acids to be modelled using I-TASSER with a bond restraint between the two S atoms because the peptide is cyclic.
However, the results contained strange bonds, and one side chain was not attached to the backbone atoms and the two S atoms are away from each other.
This is the link of the results:
https://zhanggroup.org/I-TASSER/output/S811836/
How can i solve this problem?
Re: a problem with the modeling from I-Tasser webserver
Posted: Sun Sep 07, 2025 11:01 am
by XiZhang
Dear user,
Thank you for using I-TASSER. At present, I-TASSER is tailored to model linear protein structures; unfortunately, it does not support cyclic peptides.
Best,
Xi
Re: a problem with the modeling from I-Tasser webserver
Posted: Wed Sep 10, 2025 6:36 pm
by himada97
Thank you for your reply.
By cyclic peptides i dont mean that the amide group of the first amino acid is attached to the carboxylic group of the last amino acid. The peptide i want to model just has a disulfide bond between the first and last amino acid (sequence: CTVALPGGYVRVC) but the terminals are not attached to each other.
Re: a problem with the modeling from I-Tasser webserver
Posted: Tue Sep 23, 2025 8:18 pm
by ava951robinson
Hello,
Group of the first amino acid is attached to the carboxylic group of the last amino acid. The peptide i want to model just has a disulfide bond between the first and last amino acid (sequence: CTVALPGGYVRVC) but the terminals are not attached to each other.
Re: a problem with the modeling from I-Tasser webserver
Posted: Wed Jan 07, 2026 10:54 pm
by JosepRoney
himada97 wrote: ↑Sun Sep 07, 2025 2:43 am
Hi,
I have submitted a peptide of 13 amino acids to be modelled using I-TASSER with a bond restraint between the two S atoms because the peptide is cyclic.
However, the results contained strange bonds, and one side chain was not attached to the backbone atoms and the two S atoms are away from each other.
This is the link of the results:
https://zhanggroup.org/I-TASSER/output/S811836/msn games
How can i solve this problem?
Go on! Even with bond restraints, it doesn’t establish a real covalent linkage between two residues unless it’s interpreted correctly.