HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

J. Biol. Chem., Vol. 282, Issue 11, 8356-8367, March 16, 2007

This Article Full Text Full Text (PDF) All Versions of this Article: 282/11/8356    most recent M608062200v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Xu, D. Articles by Liu, J. Search for Related Content PubMed PubMed Citation Articles by Xu, D. Articles by Liu, J. Social Bookmarking                      What's this?

Mutational Study of Heparan Sulfate 2-O-Sulfotransferase and Chondroitin Sulfate 2-O-Sulfotransferase^*

Ding Xu¹, Danyin Song, Lars C. Pedersen, and Jian Liu²

From the Division of Medicinal Chemistry and Natural Products, School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599 and Laboratory of Structural Biology, NIEHS, National Institutes of Health, Research Triangle Park, North Carolina 27709

Heparan sulfate (HS) and chondroitin sulfate (CS) are highly sulfated polysaccharides with a wide range of biological functions. Heparan sulfate 2-O-sulfotransferase (HS-2OST) transfers the sulfo group from 3'-phosphoadenosine 5'-phosphosulfate (PAPS) to the 2-OH position of the hexauronic acid that is adjacent to N-sulfated glucosamine, whereas chondroitin sulfate 2-O-sulfotransferase (CS-2OST) transfers the sulfo group to the hexauronic acid that is adjacent to N-acetylated galactosamine. Here we report a systematic mutagenesis study of HS-2OST and CS-2OST based on their structural homology to estrogen sulfotransferase and HS 3-O-sulfotransferase isoform 3 (3-OST3), for which crystal structures exist. We have identified six residues possibly involved in binding to PAPS. HS-2OST carrying mutations of these residues lacks sulfotransferase activity and the ability to bind 3'-phosphoadenosine 5'-phosphate, a PAPS analogue, as determined by isothermal titration calorimetry. Similar residues involved in binding to PAPS were also identified in CS-2OST. Additional residues that participate in carbohydrate substrate binding were also identified in both enzymes. Mutations at these residues led to the loss of sulfotransferase activity but maintained the ability to bind to phosphoadenosine 5'-phosphate. The catalytic function of HS-2OST appears to involve two histidine residues (His¹⁴⁰ and His¹⁴²), whereas only one histidine (His¹⁶⁸) of CS 2-OST is likely to be critical. This unique feature of HS 2-OST catalytic residues directed us to characterize the Drosophila heparan sulfate 2-O-sulfotransferase. The results from this study provide insight into the differences and similarities various residues play in the biological roles of the HS-2OST and CS-2OST enzymes.

Received for publication, August 22, 2006 , and in revised form, January 8, 2007.

^* This work was supported in part by National Institutes of Health Grants AI50050 and in part by the Intramural Research Program of the NIEHS, National Institutes of Health. The costs of publication of this article were defrayed in part by the payment of page charges. This article must therefore be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

¹ Recipient of a predoctoral fellowship from the American Heart Association MidAtlantic Affiliate.

² To whom correspondence should be addressed: Rm. 309, Beard Hall, University of North Carolina, Chapel Hill, NC 27599. Tel.: 919-843-6511; Fax: 919-843-5432; E-mail: jian_liu{at}unc.edu.

CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    What's this?