title: Structure of Ecballium elaterium trypsin inhibitor II (EETI-II): a rigid molecular scaffold.
abstract: 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.
authors.affiliation: Lehrstuhl für Strukturchemie, Georg-August-Universität Göttingen, Tammannstrasse 4, D37077 Göttingen, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Krätzner
authors.forename: Judit E
authors.initials: JE
authors.lastname: Debreczeni
authors.forename: Thomas
authors.initials: T
authors.lastname: Pape
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Schneider
authors.forename: Alexander
authors.initials: A
authors.lastname: Wentzel
authors.forename: Harald
authors.initials: H
authors.lastname: Kolmar
authors.forename: George M
authors.initials: GM
authors.lastname: Sheldrick
authors.forename: Isabel
authors.initials: I
authors.lastname: Uson
mesh_terms: D018360:Crystallography, X-Ray; D015394:Molecular Structure; D009154:Mutation; D010940:Plant Proteins / Q000737:chemistry* / Q000235:genetics; D011485:Protein Binding; D015202:Protein Engineering / Q000379:methods; D014361:Trypsin Inhibitors / Q000737:chemistry
chemical_list: D010940:Plant Proteins; D014361:Trypsin Inhibitors; C063950:trypsin inhibitor EETI II protein, plant