On the catalytic mechanism of polysaccharide lyases: evidence of His and Tyr involvement in heparin lysis by heparinase I and the role of Ca 2+

DOI: 10.1039/C3MB70370C

Authors: Carolina R. Córdula (Universidade Federal de São Paulo) , Marcelo Lima (Universidade Federal de São Paulo) , Samuel K. Shinjo (Universidade Federal de São Paulo) , Tarsis F. Gesteira (Universidade Federal de São Paulo) , Laércio Pol- Fachin (Universidade Federal do Rio Grande do Sul) , Vivien J. Coulson- Thomas (Universidade Federal de São Paulo) , Hugo Verli (Universidade Federal do Rio Grande do Sul) , Edwin Yates (University of Liverpool; Universidade Federal de São Paulo) , Timothy Rudd (University of Liverpool, Diamond Light Source) , Maria A. S. Pinhal (Universidade Federal de São Paulo) , Leny Toma (Universidade Federal de São Paulo) , Carl P. Dietrich (Universidade Federal de São Paulo) , Helena B. Nader (Universidade Federal de São Paulo) , Ivarne L. S. Tersariol (Universidade Federal de São Paulo)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Molecular Biosystems , VOL 10 (1) , PAGES 54 - 64

State: Published (Approved)
Published: January 2014

Abstract: The structurally diverse polysaccharide lyase enzymes are distributed from plants to animals but share common catalytic mechanisms. One, heparinase I (F. heparinum), is employed in the production of the major anticoagulant drug, low molecular weight heparin, and is a mainstay of cell surface proteoglycan analysis. We demonstrate that heparinase I specificity and efficiency depend on the cationic form of the substrate. Ca2+–heparin, in which α-L-iduronate-2-O-sulfate residues adopt 1C4 conformation preferentially, is a substrate, while Na+–heparin is an inhibitor. His and Tyr residues are identified in the catalytic step and a model based on molecular dynamics and docking is proposed, in which deprotonated His203 initiates β-elimination by abstracting the C5 proton of the α-L-iduonate-2-O-sulfate residue in the substrate, and protonated Tyr357 provides the donor to the hexosamine leaving group.

Subject Areas: Biology and Bio-materials, Chemistry


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