Open AccessStructure of Ecballium elaterium trypsin inhibitor II (EETI‐II): a rigid molecular scaffold
Author(s) -
Krätzner Ralph,
Debreczeni Judit É.,
Pape Thomas,
Schneider Thomas R.,
Wentzel Alexander,
Kolmar Harald,
Sheldrick George M.,
Uson Isabel
Publication year - 2005
Publication title -
acta crystallographica section d
Language(s) - English
Resource type - Journals
ISSN - 1399-0047
DOI - 10.1107/s0907444905021207
Subject(s) - scaffold , trypsin , chemistry , amino acid , trypsin inhibitor , molecular model , biochemistry , enzyme , computer science , database
The Ecballium elaterium trypsin inhibitor II (EETI‐II) belongs to the family of squash inhibitors and is one of the strongest inhibitors known for trypsin. The eight independent molecules of EETI‐II in the crystal structure reported here provide a good opportunity to test the hypothesis that this small cystine‐knot protein (knottin) is sufficiently rigid to be used as a molecular scaffold for protein‐engineering purposes. To extend this test, the structures of two complexes of EETI‐II with trypsin have also been determined, one carrying a four‐amino‐acid mutation of EETI‐II. The remarkable similarity of these structures confirms the rigidity of the molecular framework and hence its suitability as a molecular scaffold.