3LDI

Crystal structure of aprotinin in complex with sucrose octasulfate: unusual interactions and implication for heparin binding

Summary for 3LDI

• Entry DOI: 10.2210/pdb3ldi/pdb
• Related: 3LDJ 3LDM
• Descriptor: Pancreatic trypsin inhibitor, SULFATE ION, MERCURY (II) ION, ... (5 entities in total)
• Functional Keywords: aprotinin, sucrose octasulfate, disulfide bond, protease inhibitor, secreted, serine protease inhibitor, hydrolase inhibitor
• Biological source: Bos taurus (Bovine)
• Cellular location: Secreted: P00974
• Total number of polymer chains: 5
• Total formula weight: 35554.11

Authors

Yang, I.S.,Kim, T.G.,Park, B.S.,Kim, K.H. (deposition date: 2010-01-13, release date: 2010-06-23, Last modification date: 2024-10-30)

Primary citation

Yang, I.S.,Kim, T.G.,Park, B.S.,Cho, K.J.,Lee, J.-H.,Park, Y.,Kim, K.H.
Crystal structures of aprotinin and its complex with sucrose octasulfate reveal multiple modes of interactions with implications for heparin binding
Biochem.Biophys.Res.Commun., 397:429-435, 2010

PubMed Abstract: The crystal structures of aprotinin and its complex with sucrose octasulfate (SOS), a polysulfated heparin analog, were determined at 1.7-2.6A resolutions. Aprotinin is monomeric in solution, which associates into a decamer at high salt concentrations. Sulfate ions serve to neutralize the basic amino acid residues of aprotinin to stabilize the decameric aprotinin. Whereas SOS interacts with heparin binding proteins at 1:1 molar ratio, SOS was surprisingly found to induce strong agglutination of aprotinins. Five molecules of aprotinin interact with one molecule of the sulfated sugar, which is stabilized by electrostatic interactions between the positively charged residues of aprotinin and sulfate groups of SOS. The multiple binding modes of SOS with five individual aprotinin molecules may represent the diverse patterns of potential heparin binding to aprotinin, reflecting the interactions of densely packed protein molecules along the heparin polymer.

PubMed: 20529698
DOI: 10.1016/j.bbrc.2010.05.113

Experimental method

X-RAY DIFFRACTION (2.2 Å)