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PDBsum entry 1dtk
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Presynaptic neurotoxin
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PDB id
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1dtk
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References listed in PDB file
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Key reference
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Title
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Nuclear magnetic resonance solution structure of dendrotoxin k from the venom of dendroaspis polylepis polylepis.
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Authors
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K.D.Berndt,
P.Güntert,
K.Wüthrich.
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Ref.
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J Mol Biol, 1993,
234,
735-750.
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PubMed id
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Abstract
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The solution structure of dendrotoxin K (Toxin K), a protein consisting of one
polypeptide chain with 57 residues purified from the venom of the black mamba,
Dendroaspis polylepis polylepis, was determined by nuclear magnetic resonance
(NMR) spectroscopy. On the basis of virtually complete sequence-specific 1H NMR
assignments, including individual assignments for 38 pairs of diastereotopic
substituents and side-chain amide protons, a total of 818 nuclear Overhauser
effect distance constraints and 123 dihedral angle constraints were identified.
Using this input, the solution structure of Toxin K was calculated with the
program DIANA, and refined by restrained energy-minimization with a modified
version of the program AMBER. The average root-mean-square deviation (r.m.s.d.)
relative to the mean atomic co-ordinates of the 20 conformers selected to
represent the solution structure is 0.31 A for all backbone atoms N, C alpha and
C', and 0.90 A for all heavy-atoms of residues 2 to 56. The solution structure
of Toxin K is very similar to the solution structure of the basic pancreatic
trypsin inhibitor (BPTI) and the X-ray crystal structure of the
alpha-dendrotoxin from Dendroaspis angusticeps (alpha-DTX), with r.m.s.d. values
of 1.31 A and 0.92 A, respectively, for the backbone atoms of residues 2 to 56.
Some local structural differences between Toxin K and BPTI are directly related
to the fact that intermolecular interactions with two of the four internal
molecules of hydration water in BPTI are replaced by intramolecular hydrogen
bonds in Toxin K.
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Secondary reference #1
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Title
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Assignment of the 1h nuclear magnetic resonance spectrum of the trypsin inhibitor homologue k from dendroaspis polylepis polylepis. Two-Dimensional nuclear magnetic resonance at 360 and 500 mhz.
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Authors
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R.M.Keller,
R.Baumann,
E.H.Hunziker-Kwik,
F.J.Joubert,
K.Wüthrich.
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Ref.
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J Mol Biol, 1983,
163,
623-646.
[DOI no: ]
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PubMed id
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Figure 5.
FIG. 5. Polypeptide backbone segment. The through-space distances, dl, d, and d3, used for the
squential resonance assignments are indicated by arrows. The relationships between d,, d2 and d3 and
th dihedral angles I+$, 4i and x,! have been discussed previously (Billeter et al., 1982).
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Figure 9.
FIG. 9. Combined COSY-NOESY d, connectivity diagram, same spectra and same prsentation as in
Fig. 8. The connectivity patterns are indicated by solid lines for the following segments of the inhibitor
K polypeptide chain : 57 to 56 48 to 47 and 46 to 43.
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The above figures are
reproduced from the cited reference
with permission from Elsevier
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Secondary reference #2
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Title
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Evolutionary conservation and variation of protein folding pathways. Two protease inhibitor homologues from black mamba venom.
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Authors
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M.Hollecker,
T.E.Creighton.
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Ref.
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J Mol Biol, 1983,
168,
409-437.
[DOI no: ]
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PubMed id
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Figure 1.
FIo. I. Te amino acid sequences of black mamba proteins I and K and of BPTI, taken from
Strydom (1973). acid iden~ties areindicatedbycapitalletters.
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Figure 7.
Fro. 7. Kineticsof unfolding of(30-51, 5-55) of protein I (left) and of refolding ofthe reduced form
of protein K (right), both with Cysl4 and 38thiol groups carboxymethyated. Unfolding was produced
by 1 mM and 5mM-~T~s H ((O) and (O), respectively). Refolding was with 20mM-D~. Th points
represent the experimental values of therelative concentrations of the various species, the curves were
calculated with te rate constants of Table 3.
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The above figures are
reproduced from the cited reference
with permission from Elsevier
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Secondary reference #3
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Title
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Protease inhibitors as snake venom toxins.
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Author
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D.J.Strydom.
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Ref.
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Nat New Biol, 1973,
243,
88-89.
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PubMed id
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