3S8K

Crystal structure of a papaya latex serine protease inhibitor (PPI) at 1.7A resolution

Summary for 3S8K

• Entry DOI: 10.2210/pdb3s8k/pdb
• Related: 3S8J
• Descriptor: Latex serine proteinase inhibitor, alpha-L-fucopyranose-(1-3)-[2-acetamido-2-deoxy-beta-D-glucopyranose-(1-4)]2-acetamido-2-deoxy-beta-D-glucopyranose, COBALT (II) ION, ... (7 entities in total)
• Functional Keywords: kunitz-sti fold, protease inhibitor, hydrolase inhibitor
• Biological source: Carica papaya (mamon)
• Total number of polymer chains: 2
• Total formula weight: 43719.69

Authors

Garcia-Pino, A. (deposition date: 2011-05-29, release date: 2011-11-02, Last modification date: 2024-11-20)

Primary citation

Azarkan, M.,Martinez-Rodriguez, S.,Buts, L.,Baeyens-Volant, D.,Garcia-Pino, A.
The plasticity of the beta-Trefoil fold constitutes an evolutionary platform for protease inhibition
J.Biol.Chem., 286:43726-43734, 2011

PubMed Abstract: Proteases carry out a number of crucial functions inside and outside the cell. To protect the cells against the potentially lethal activities of these enzymes, specific inhibitors are produced to tightly regulate the protease activity. Independent reports suggest that the Kunitz-soybean trypsin inhibitor (STI) family has the potential to inhibit proteases with different specificities. In this study, we use a combination of biophysical methods to define the structural basis of the interaction of papaya protease inhibitor (PPI) with serine proteases. We show that PPI is a multiple-headed inhibitor; a single PPI molecule can bind two trypsin units at the same time. Based on sequence and structural analysis, we hypothesize that the inherent plasticity of the β-trefoil fold is paramount in the functional evolution of this family toward multiple protease inhibition.

PubMed: 22027836
DOI: 10.1074/jbc.M111.291310

Experimental method

X-RAY DIFFRACTION (1.7 Å)