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

J. Biol. Chem., Vol. 282, Issue 1, 337-344, January 5, 2007

This Article Full Text Full Text (PDF) Supplemental Data All Versions of this Article: 282/1/337    most recent M607569200v1 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 Tracy, B. S. Articles by DeAngelis, P. L. Search for Related Content PubMed PubMed Citation Articles by Tracy, B. S. Articles by DeAngelis, P. L. Social Bookmarking                      What's this?

Acceptor Specificity of the Pasteurella Hyaluronan and Chondroitin Synthases and Production of Chimeric Glycosaminoglycans^*

Breca S. Tracy, Fikri Y. Avci, Robert J. Linhardt, and Paul L. DeAngelis¹

From the Department of Biochemistry and Molecular Biology, Oklahoma Center for Medical Glycobiology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma 73104 and the Departments of Chemistry and Chemical Biology and of Biology and Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Biotechnology Center, Troy, New York 12180-3590

The hyaluronan (HA) synthase, PmHAS, and the chondroitin synthase, PmCS, from the Gram-negative bacterium Pasteurella multocida polymerize the glycosaminoglycan (GAG) sugar chains HA or chondroitin, respectively. The recombinant Escherichia coli-derived enzymes were shown previously to elongate exogenously supplied oligosaccharides of their cognate GAG (e.g. HA elongated by PmHAS). Here we show that oligosaccharides and polysaccharides of certain noncognate GAGs (including sulfated and iduronic acid-containing forms) are elongated by PmHAS (e.g. chondroitin elongated by PmHAS) or PmCS. Various acceptors were tested in assays where the synthase extended the molecule with either a single monosaccharide or a long chain (10^2-4 sugars). Certain GAGs were very poor acceptors in comparison to the cognate molecules, but elongated products were detected nonetheless. Overall, these findings suggest that for the interaction between the acceptor and the enzyme (a) the orientation of the hydroxyl at the C-4 position of the hexosamine is not critical, (b) the conformation of C-5 of the hexuronic acid (glucuronic versus iduronic) is not crucial, and (c) additional negative sulfate groups are well tolerated in certain cases, such as on C-6 of the hexosamine, but others, including C-4 sulfates, were not or were poorly tolerated. In vivo, the bacterial enzymes only process unsulfated polymers; thus it is not expected that the PmCS and PmHAS catalysts would exhibit such relative relaxed sugar specificity by acting on a variety of animal-derived sulfated or epimerized GAGs. However, this feature allows the chemoenzymatic synthesis of a variety of chimeric GAG polymers, including mimics of proteoglycan complexes.

Received for publication, August 8, 2006 , and in revised form, October 23, 2006.

^* This work was supported in part by National Science Foundation Grant MCB-9876193, Oklahoma Center for Advancement of Science and Technology Health Research Grant HR02-036R (to P. L. D.), and National Institutes of Health Grants GM38060 (to R. J. L.), HL062244 (to R. J. L. and P. L. D.), and Health Grant R24-GM-61894. 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.

The on-line version of this article (available at http://www.jbc.org) contains supplemental Fig. S1.

¹ To whom correspondence should be addressed: Dept. of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, 940 Stanton L. Young Blvd., Oklahoma City, OK 73104. Tel.: 405-271-2227; Fax: 405-271-3092; E-mail: paul-deangelis{at}ouhsc.edu.

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