1LQ8

Crystal structure of cleaved protein C inhibitor

Summary for 1LQ8

• Entry DOI: 10.2210/pdb1lq8/pdb
• Related: 1EZX
• Descriptor: plasma serine protease inhibitor, 2-acetamido-2-deoxy-alpha-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, 2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)-2-acetamido-2-deoxy-beta-D-glucopyranose, ... (8 entities in total)
• Functional Keywords: serpin, protease, inhibitor, heparin, retinoic acid, protein c, blood clotting
• Biological source: Homo sapiens (human); More
• Cellular location: Secreted: P05154 P05154
• Total number of polymer chains: 8
• Total formula weight: 172599.74

Authors

Huntington, J.A.,Kjellberg, M.,Stenflo, J. (deposition date: 2002-05-09, release date: 2003-02-11, Last modification date: 2024-11-13)

Primary citation

Huntington, J.A.,Kjellberg, M.,Stenflo, J.
Crystal Structure of Protein C Inhibitor Provides Insights into Hormone Binding and Heparin Activation
Structure, 11:205-211, 2003

PubMed Abstract: Protein C inhibitor (PCI) is a member of the serpin family that has many biological functions. In blood it acts as a procoagulant, and, in the seminal vesicles, it is required for spermatogenesis. The activity of PCI is affected by heparin binding in a manner unique among the heparin binding serpins, and, in addition, PCI binds hydrophobic hormones with apparent specificity for retinoids. Here we present the 2.4 A crystallographic structure of reactive center loop (RCL) cleaved PCI. A striking feature of the structure is a two-turn N-terminal shortening of helix A, which creates a large hydrophobic pocket that docking studies indicate to be the retinoid binding site. On the basis of surface electrostatic properties, a novel mechanism for heparin activation is proposed.

PubMed: 12575940
DOI: 10.1016/S0969-2126(02)00944-9

Experimental method

X-RAY DIFFRACTION (2.4 Å)