Affinity, kinetic, and structural study of the interaction of 3-O-sulfotransferase isoform 1 with heparan sulfate.
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 (K(D) = 2.79 microM), 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.
Muñoz
Eva
E
Department of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180, USA.
Xu
Ding
D
Kemp
Melissa
M
Zhang
Fuming
F
Liu
Jian
J
Linhardt
Robert J
RJ
D000818:Animals; D002417:Cattle; D018360:Crystallography, X-Ray; D006497:Heparan Sulfate / Q000737:chemistry* / Q000378:metabolism*; D007527:Isoenzymes / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D007700:Kinetics; D051379:Mice; D008958:Models, Molecular; D009154:Mutation / Q000235:genetics; D017434:Protein Structure, Tertiary; D013379:Substrate Specificity; D015238:Sulfotransferases / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D020349:Surface Plasmon Resonance
D006497:Heparan Sulfate; D007527:Isoenzymes; D015238:Sulfotransferases; C501522:Hs3st6 protein, mouse