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PDBsum entry 1h9h
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Hydrolase inhibitor
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PDB id
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1h9h
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Contents |
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* Residue conservation analysis
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References listed in PDB file
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Key reference
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Title
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Structure of ecballium elaterium trypsin inhibitor ii (eeti-Ii): a rigid molecular scaffold.
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Authors
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R.Krätzner,
J.E.Debreczeni,
T.Pape,
T.R.Schneider,
A.Wentzel,
H.Kolmar,
G.M.Sheldrick,
I.Uson.
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Ref.
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Acta Crystallogr D Biol Crystallogr, 2005,
61,
1255-1262.
[DOI no: ]
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PubMed id
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Abstract
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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.
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Figure 3.
Figure 3
Dimer formed by the molecules A and B. Molecule pairs CD and EF display a similar
arrangement. The sodium ion is shown as a solid ball.
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Figure 6.
Figure 6
Least-squares superpositions of all main-chain atoms of EETI-II. (a) All eight independent
molecules in the uncomplexed structure; (b) uncomplexed (black) and complexed (red)
EETI-II and the NMR model (green); (c) uncomplexed EETI-II (black), the trypsin-EETI-II-
[beta] TNNK complex (red) and CMTI-I (blue).
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The above figures are
reprinted
by permission from the IUCr:
Acta Crystallogr D Biol Crystallogr
(2005,
61,
1255-1262)
copyright 2005.
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Secondary reference #1
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Title
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Sequence requirements of the gpng beta-Turn of the ecballium elaterium trypsin inhibitor ii explored by combinatorial library screening.
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Authors
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A.Wentzel,
A.Christmann,
R.Krätzner,
H.Kolmar.
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Ref.
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J Biol Chem, 1999,
274,
21037-21043.
[DOI no: ]
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PubMed id
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Figure 4.
Fig. 4. Occurrence of amino acid residues in the 22-25
segment of trypsin-binding EETI-II variants. For each residue,
the score was calculated as described under "Experimental
Procedures," which reflects the preference to be found in the
set of trypsin-binding EETI-II variants compared with the
unselected library. Residues are ordered according to their
overall turn potentials (14). These indicate the preference for
each residue to occur in a  -turn
generally and are averaged over a large data set of -turns from
various proteins and over all classified turn types (14).
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Figure 5.
Fig. 5. Folding kinetics of EETI-II wild type, EETI- ^NEDE, and
EETI- ^TNNK. A-C,
HPLC analysis of the acid trapped folding intermediates of
EETI-II wild type (A), EETI- ^NEDE (B),
and EETI- ^TNNK (C).
Proteins were allowed to refold from the fully reduced form in
the presence of 100 mM NH[4]HCO[3] pH 9.1. Acid-trapped
intermediates, taken at the indicated time points were analyzed
by reversed-phase HPLC. R indicates the reduced form of the
respective variant, I the predominant folding intermediate, and
N the native form. D-F, concentration of fully reduced peptide (
 ),
dihydro-2,19-EETI-II folding intermediate (  circle ),
and native peptide (  ),
expressed as percentage of total peptide, after various times of
incubation of reduced peptide. The relative concentrations were
determined from the HPLC peak areas.
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The above figures are
reproduced from the cited reference
with permission from the ASBMB
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Secondary reference #2
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Title
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Min-21 and min-23, The smallest peptides that fold like a cystine-Stabilized beta-Sheet motif: design, Solution structure, And thermal stability.
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Authors
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A.Heitz,
D.Le-Nguyen,
L.Chiche.
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Ref.
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Biochemistry, 1999,
38,
10615-10625.
[DOI no: ]
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PubMed id
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Secondary reference #3
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Title
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Use of restrained molecular dynamics in water to determine three-Dimensional protein structure: prediction of the three-Dimensional structure of ecballium elaterium trypsin inhibitor ii.
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Authors
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L.Chiche,
C.Gaboriaud,
A.Heitz,
J.P.Mornon,
B.Castro,
P.A.Kollman.
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Ref.
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Proteins, 1989,
6,
405-417.
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PubMed id
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