1pmc

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spinqualitylabelsall models PDB ID 1pmc Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image
Resources:	FirstGlance, OCA, PDBsum, RCSB
Coordinates:	save as pdb, mmCIF, xml

PROTEINASE INHIBITOR PMP-C (NMR, 36 STRUCTURES)

Overview

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.

About this Structure

1PMC is a Single protein structure of sequence from Locusta migratoria. Full crystallographic information is available from OCA.

Reference

Solution structure of PMP-C: a new fold in the group of small serine proteinase inhibitors., Mer G, Hietter H, Kellenberger C, Renatus M, Luu B, Lefevre JF, J Mol Biol. 1996 Apr 26;258(1):158-71. PMID:8613985

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