 |
PDBsum entry 1pce
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Proteinase inhibitor(kazal type)
|
PDB id
|
|
|
|
1pce
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Solution structure and dynamics of pec-60, A protein of the kazal type inhibitor family, Determined by nuclear magnetic resonance spectroscopy.
|
|
|
Authors
|
|
E.Liepinsh,
K.D.Berndt,
R.Sillard,
V.Mutt,
G.Otting.
|
|
|
Ref.
|
|
J Mol Biol, 1994,
239,
137-153.
|
|
|
PubMed id
|
|
|
|
|
Note In the PDB file this reference is
annotated as "TO BE PUBLISHED".
The citation details given above were identified by an automated
search of PubMed on title and author
names, giving a
perfect match.
|
|
|
|
Abstract
|
|
|
The three-dimensional solution structure of porcine PEC-60, a 60 amino acid
residue protein of the Kazal type family of proteinase inhibitors, was
determined by nuclear magnetic resonance (NMR) spectroscopy. The structure
determination is based on nearly complete 1H, 13C and 15N resonance assignments
including stereospecific 1H resonance assignments for 40 pairs of methylene
protons and isopropyl methyl groups. The stereospecific resonance assignments of
the beta-protons were supported by heteronuclear long-range correlation
experiments recorded at natural 13C and 15N isotopic abundances. A group of 20
conformers were calculated using the experimentally derived NMR constraints with
the program DIANA, and energy-minimized in a 4 A water shell using the program
OPAL. The average of the root-mean-square deviations relative to the mean
structure of the 20 conformers selected to represent the solution structure of
PEC-60 is 0.55 A for the backbone atoms of residues 6 to 10 and 24 to 60.
Disordered conformations are observed for the amino-terminal pentapeptide and
the polypeptide segment containing residues 11 to 23. The NMR structure confirms
the structural similarity of PEC-60 to the Kazal type family of proteinase
inhibitors which had been previously suggested on the basis of amino acid
homology. The well-defined part of PEC-60 contains a short three-stranded
anti-parallel beta-sheet involving the residues 27 to 29, 33 to 35 and 53 to 56
with a beta-bulge at residue 55, a type I turn comprising residues 29 to 32, and
an alpha-helix involving the residues 37 to 48. T1(13C) relaxation measurements
of the alpha-carbons and linewidth measurements of the amide proton signals
indicate substantially increased mobility on the pico- to nanosecond time-scale
for the amino-terminal pentapeptide as well as within the loop comprising
residues 11 to 23. The structure of PEC-60 is compared to the X-ray crystal
structures of homologous Kazal type proteinase inhibitors and the dynamic
properties of PEC-60 are discussed with respect to the observed lack of any
substantial trypsin inhibiting activity.
|
|
|
|
|
|
|
