Abstract
The 3-O-sulfonation of glucosamine residues in heparan sulfate (HS) by 3-O-sulfotransferase (3-OST) is a key substitution that is present in HS sequences of biological importance, in particular HS anticoagulant activity. Six different isoforms of 3-OST have been identified that exhibit different substrate specificity. In this paper the affinity and kinetics of the interaction between 3-O-sulfotransferase isoform 1 (3-OST-1) and HS have been examined using surface plasmon resonance (SPR). 3-OST-1 binds with micomolar affinity to HS (KD = 2.79 μM), and this interaction is apparently independent of the presence of the coenzyme, 3′-phosphoadenosine 5′-phosphosulfate (PAPS). A conformational change in the complex has also been detected, supporting data from previous studies. Selected 3-OST-1 mutants have provided valuable information of amino acid residues that participate in 3-OST-1 interaction with HS substrate and its catalytic activity. The results from this study contribute to understanding the substrate specificity among the 3-OST isoforms and in the mechanism of 3-OST-1-catalyzed biosynthesis of anticoagulant HS.
Original language | English |
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Pages (from-to) | 5122-5128 |
Number of pages | 7 |
Journal | Biochemistry |
Volume | 45 |
Issue number | 16 |
DOIs | |
State | Published - 25 Apr 2006 |
Externally published | Yes |