1R8N

The Crystal Structure of the Kunitz (STI) Type Inhibitor from Seeds of Delonix regia

Summary for 1R8N

• Entry DOI: 10.2210/pdb1r8n/pdb
• Related: 1R8O
• Descriptor: Kunitz trypsin inhibitor (2 entities in total)
• Functional Keywords: kunitz-type trypsin/kallikrein inhibitor, beta-trefoil fold, flamboyant, delonix regia, hydrolase inhibitor
• Biological source: Delonix regia
• Cellular location: Secreted: P83667
• Total number of polymer chains: 1
• Total formula weight: 20197.72

Authors

Krauchenco, S.,Pando, S.C.,Marangoni, S.,Polikarpov, I. (deposition date: 2003-10-27, release date: 2004-05-25, Last modification date: 2024-10-30)

Primary citation

Krauchenco, S.,Pando, S.C.,Marangoni, S.,Polikarpov, I.
Crystal structure of the Kunitz (STI)-type inhibitor from Delonix regia seeds.
Biochem.Biophys.Res.Commun., 312:1303-1308, 2003

PubMed Abstract: The three-dimensional structure of a novel Kunitz (STI) family member, an inhibitor purified from Delonix regia seeds (DrTI), was solved by molecular replacement method and refined, respectively, to R(factor) and R(free) values of 21.5% and 25.3% at 1.75A resolution. The structure has a classical beta-trefoil fold, however, differently from canonical Kunitz type (STI) inhibitors, its reactive site loop has an insertion of one residue, Glu68, between the residues P1 and P2. Surprisingly, DrTI is an effective inhibitor of trypsin and human plasma kallikrein, but not of chymotrypsin and tissue kallikrein. Putative structural grounds of such specificity are discussed.

PubMed: 14652016
DOI: 10.1016/j.bbrc.2003.11.062

Experimental method

X-RAY DIFFRACTION (1.75 Å)