 |
PDBsum entry 1pmc
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
 |
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Proteinase inhibitor
|
PDB id
|
|
|
|
1pmc
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
References listed in PDB file
|
|
|
Key reference
|
|
|
Title
|
|
Solution structure of pmp-C: a new fold in the group of small serine proteinase inhibitors.
|
|
|
Authors
|
|
G.Mer,
H.Hietter,
C.Kellenberger,
M.Renatus,
B.Luu,
J.F.Lefèvre.
|
|
|
Ref.
|
|
J Mol Biol, 1996,
258,
158-171.
|
|
|
PubMed id
|
|
|
|
|
|
Abstract
|
|
|
The solution structure and the disulfide pairings of a 36-residue proteinase
inhibitor isolated from the insect Locusta migratoria have been determined using
NMR spectroscopy and simulated annealing calculations. The peptide, termed
PMP-C, was previously shown to inhibit bovine alpha-chymotrypsin as well as
human leukocyte elastase, and was also found to block high-voltage-activated
Ca2+ currents in rat sensory neurones. PMP-C has a prolate ellipsoid shape and
adopts a tertiary fold hitherto unobserved in the large group of small
"canonical" proteinase inhibitors. The over-all fold consists mainly of three
strands arranged in a right-handed twisted, antiparallel, beta-sheet that
demarcates a cavity, together with a linear amino-terminal segment oriented
almost perpendicular to the three strands of the beta-sheet. Inside the cavity a
phenyl ring constitutes the centre of a hydrophobic core. The proteinase binding
loop is located in the carboxy-terminal part of the molecule, between two
cysteine residues involved in disulfide bridges. Its conformation resembles that
found in other small canonical proteinase inhibitors. A comparison of PMP-C
structure with the recently published solution structure of the related peptide
PMP-D2 shows that the most significant differences are complementary changes
involved in the stabilization of similar folds. This comparison led us to review
the structure of PMP-D2 and to identify two salt bridges in PMP-D2.
|
|
|
|
|
|
|
