1PMC

PROTEINASE INHIBITOR PMP-C (NMR, 36 STRUCTURES)

Summary for 1PMC

• Entry DOI: 10.2210/pdb1pmc/pdb
• Descriptor: PROTEINASE INHIBITOR PMP-C (1 entity in total)
• Functional Keywords: calcium channel blocker, proteinase inhibitor
• Biological source: Locusta migratoria (migratory locust)
• Cellular location: Secreted: P80060
• Total number of polymer chains: 1
• Total formula weight: 3785.36

Authors

Mer, G.,Hietter, H.,Lefevre, J.-F. (deposition date: 1995-09-17, release date: 1996-01-29, Last modification date: 2024-10-23)

Primary citation

Mer, G.,Hietter, H.,Kellenberger, C.,Renatus, M.,Luu, B.,Lefevre, J.F.
Solution structure of PMP-C: a new fold in the group of small serine proteinase inhibitors.
J.Mol.Biol., 258:158-171, 1996

PubMed 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.

PubMed: 8613985
DOI: 10.1006/jmbi.1996.0240

Experimental method

SOLUTION NMR