# Modified amino acids in ligands

**URL:** <https://ask.bioexcel.eu/t/modified-amino-acids-in-ligands/432>\
**Category:** HADDOCK\
**Created:** [August 2, 2017, 6:53pm UTC](https://ask.bioexcel.eu/t/modified-amino-acids-in-ligands/432 "2017-08-02T18:53:08Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Sandeep\_Verma](https://avatars.discourse-cdn.com/v4/letter/s/ec9cab/32.png) [@Sandeep\_Verma](https://ask.bioexcel.eu/u/Sandeep_Verma)\
**Post date:** [August 2, 2017, 6:53pm UTC](https://ask.bioexcel.eu/t/modified-amino-acids-in-ligands/432/1 "2017-08-02T18:53:08Z")

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The HADDOCK category is meant to discuss any HADDOCK-related issue. For general information about HADDOCK refer to [http://www.bonvinlab.org/software/haddock2.2](http://www.bonvinlab.org/software/haddock2.2)  
I want to predict active residues in ligands with CPORT but this pdb file contain 7 modified amino acids like dehydroalanine, dehydrobutyrine and alpha amino butyric acids. when i run CPORT it show error. please provide solution.

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**Author:** ![amjjbonvin](https://dub1.discourse-cdn.com/flex013/user_avatar/ask.bioexcel.eu/amjjbonvin/32/23_2.png) [@amjjbonvin](https://ask.bioexcel.eu/u/amjjbonvin)\
**Post date:** [August 3, 2017, 6:58am UTC](https://ask.bioexcel.eu/t/modified-amino-acids-in-ligands/432/2 "2017-08-03T06:58:39Z")

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It simply won’t work… Or change those amino acids to a regular one.