8ZCR

Structure of PI9

Replaces:  8H4X

Summary for 8ZCR

• Entry DOI: 10.2210/pdb8zcr/pdb
• Descriptor: Serpin B9, ZINC ION, 1,2-ETHANEDIOL, ... (5 entities in total)
• Functional Keywords: serpin, x-ray crystallization, pi9, helix d, cytosolic protein
• Biological source: Homo sapiens (human); More
• Total number of polymer chains: 2
• Total formula weight: 43717.85

Authors

Zhou, A.,Yan, T. (deposition date: 2024-04-30, release date: 2024-11-13, Last modification date: 2024-12-25)

Primary citation

Yan, T.,Zhou, A.
Crystallization and crystallographic studies of human serine protease inhibitor (serpin) B9.
Acta Crystallogr.,Sect.F, 80:286-293, 2024

PubMed Abstract: Serine protease inhibitor B9 (serpin B9, also known as protease inhibitor 9 or PI9) plays a critical role in regulating the immune response by specifically inhibiting granzyme B, a serine protease found in cytotoxic T lymphocytes and natural killer cells. Despite its potential as an anticancer drug target, the structural details of serpin B9 have remained elusive until now. In this study, a cleaved form of recombinant human serpin B9 was successfully prepared and crystallized. The crystals belonged to space group P222, with unit-cell parameters a = 68.51, b = 82.32, c = 101.17 Å, and an X-ray diffraction data set was collected at 1.9 Å resolution. The structure shows that serpin B9 adopts a relaxed conformation, with its cleaved reactive-centre loop inserted into the central β-sheet. Unlike other serpins, serpin B9 shows significant structural deviations around helix D, with a larger surface cavity, which could serve as a promising target for small-molecule inhibitors.

PubMed: 39382088
DOI: 10.1107/S2053230X24009439

Experimental method

X-RAY DIFFRACTION (1.93 Å)