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

This Article Full Text Full Text (PDF) 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 HighWire Citing Articles via Google Scholar Google Scholar Articles by Hoylaerts, M. F. Articles by Millán, J. L. Search for Related Content PubMed PubMed Citation Articles by Hoylaerts, M. F. Articles by Millán, J. L. Social Bookmarking                      What's this?

Volume 272, Number 36, Issue of September 5, 1997 pp. 22781-22787
©1997 by The American Society for Biochemistry and Molecular Biology, Inc.

Mammalian Alkaline Phosphatases Are Allosteric Enzymes

(Received for publication, April 11, 1997, and in revised form, July 11, 1997)

Marc F. Hoylaerts ^§ , Thomas Manes ^§¶ and José Luis Millán ^§¶

From the  Center for Molecular and Vascular Biology, Katholicke Universiteit Leuven, Leuven, Belgium, the ^§ Burnham Institute, La Jolla Cancer Research Center, La Jolla, California 92037, and the ^¶ Department of Medical Genetics, Umeå University, S-901 85 Umeå, Sweden

Mammalian alkaline phosphatases (APs) are zinc-containing metalloenzymes encoded by a multigene family and functional as dimeric molecules. Using human placental AP (PLAP) as a paradigm, we have investigated whether the monomers in a given PLAP dimer are subject to cooperativity during catalysis following an allosteric model or act via a half-of-sites model, in which at any time only one single monomer is operative. Wild type and mutant PLAP homodimers and heterodimers were produced by stably transfecting Chinese hamster ovary cells with mutagenized PLAP cDNAs followed by enzyme extraction, purification, and characterization. [Gly⁴²⁹]PLAP manifested negative cooperativity when partially metalated as a consequence of the reduced affinity of the incompletely metalated AP monomers for the substrate. Upon full metalation with Zn²⁺, however, the negative cooperativity disappeared. To distinguish between an allosteric and a half-of-sites model, a [Gly⁴²⁹]PLAP-[Ser⁸⁴]PLAP heterodimer was produced by combining monomers displaying high and low sensitivity to the uncompetitive inhibitor L-Leu as well as a [Gly⁴²⁹]PLAP-[Ala⁹²]PLAP heterodimer combining a catalytically active and inactive monomer, respectively. The L-Leu inhibition profile of the [Gly⁴²⁹]PLAP-[Ser⁸⁴]PLAP heterodimer was intermediate to that for each homodimer as predicted by the allosteric model. Likewise, the [Gly⁴²⁹]PLAP-[Ala⁹²]PLAP heterodimer was catalytically active, confirming that AP monomers act independently of each other. Although heterodimers are structurally asymmetrical, they migrate in starch gels with a smaller than expected weighted electrophoretic mobility, are more stable to heat denaturation than expected, and are more sensitive to L-Leu inhibition than predicted by a strict noncooperative model. We conclude that fully metalated mammalian APs are noncooperative allosteric enzymes but that the stability and catalytic properties of each monomer are controlled by the conformation of the second AP subunit.

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

This article has been cited by other articles:

				S. Lee, C. Faux, J. Nixon, D. Alete, J. Chilton, M. Hawadle, and A. W. Stoker Dimerization of Protein Tyrosine Phosphatase {sigma} Governs both Ligand Binding and Isoform Specificity Mol. Cell. Biol., March 1, 2007; 27(5): 1795 - 1808. [Abstract] [Full Text] [PDF]

				P. Llinas, M. Masella, T. Stigbrand, A. Menez, E. A. Stura, and M. H. Le Du Structural studies of human alkaline phosphatase in complex with strontium: Implication for its secondary effect in bones. Protein Sci., July 1, 2006; 15(7): 1691 - 1700. [Abstract] [Full Text] [PDF]

				C. Yuan, C. J. Rieke, G. Rimon, B. A. Wingerd, and W. L. Smith Partnering between monomers of cyclooxygenase-2 homodimers PNAS, April 18, 2006; 103(16): 6142 - 6147. [Abstract] [Full Text] [PDF]

				L. Zhang, R. Buchet, and G. Azzar Phosphate Binding in the Active Site of Alkaline Phosphatase and the Interactions of 2-Nitrosoacetophenone with Alkaline Phosphatase-Induced Small Structural Changes Biophys. J., June 1, 2004; 86(6): 3873 - 3881. [Abstract] [Full Text] [PDF]

				J. M. Gillette and S. M. Nielsen-Preiss The role of annexin 2 in osteoblastic mineralization J. Cell Sci., January 22, 2004; 117(3): 441 - 449. [Abstract] [Full Text] [PDF]

				M Herasse, M Spentchian, A Taillandier, K Keppler-Noreuil, A N M Fliorito, J Bergoffen, R Wallerstein, C Muti, B Simon-Bouy, and E Mornet Molecular study of three cases of odontohypophosphatasia resulting from heterozygosity for mutations in the tissue non-specific alkaline phosphatase gene J. Med. Genet., August 1, 2003; 40(8): 605 - 609. [Full Text] [PDF]

				T. Harada, I. Koyama, T. Kasahara, D. H. Alpers, and T. Komoda Heat shock induces intestinal-type alkaline phosphatase in rat IEC-18 cells Am J Physiol Gastrointest Liver Physiol, February 1, 2003; 284(2): G255 - G262. [Abstract] [Full Text] [PDF]

				M.-H. Le Du and J. L. Millan Structural Evidence of Functional Divergence in Human Alkaline Phosphatases J. Biol. Chem., December 13, 2002; 277(51): 49808 - 49814. [Abstract] [Full Text] [PDF]

				A. Kozlenkov, T. Manes, M. F. Hoylaerts, and J. L. Millan Function Assignment to Conserved Residues in Mammalian Alkaline Phosphatases J. Biol. Chem., June 14, 2002; 277(25): 22992 - 22999. [Abstract] [Full Text] [PDF]

				K. McDougall, C. Plumb, W.A. King, and A. Hahnel Inhibitor Profiles of Alkaline Phosphatases in Bovine Preattachment Embryos and Adult Tissues J. Histochem. Cytochem., March 1, 2002; 50(3): 415 - 422. [Abstract] [Full Text] [PDF]

				H.-C. Hung and G.-G. Chang Differentiation of the slow-binding mechanism for magnesium ion activation and zinc ion inhibition of human placental alkaline phosphatase Protein Sci., January 1, 2001; 10(1): 34 - 45. [Abstract] [Full Text]

				A. M. Fong, H. P. Erickson, J. P. Zachariah, S. Poon, N. J. Schamberg, T. Imai, and D. D. Patel Ultrastructure and Function of the Fractalkine Mucin Domain in CX3C Chemokine Domain Presentation J. Biol. Chem., February 11, 2000; 275(6): 3781 - 3786. [Abstract] [Full Text] [PDF]

				Z. CHANG, K. MEYER, A. C. RAPRAEGER, and A. FRIEDL Differential ability of heparan sulfate proteoglycans to assemble the fibroblast growth factor receptor complex in situ FASEB J, January 1, 2000; 14(1): 137 - 144. [Abstract] [Full Text]

				T. Manes, M. F. Hoylaerts, R. Muller, F. Lottspeich, W. Holke, and J. L. Millan Genetic Complexity, Structure, and Characterization of Highly Active Bovine Intestinal Alkaline Phosphatases J. Biol. Chem., September 4, 1998; 273(36): 23353 - 23360. [Abstract] [Full Text] [PDF]

				M. H. Le Du, T. Stigbrand, M. J. Taussig, A. Menez, and E. A. Stura Crystal Structure of Alkaline Phosphatase from Human Placenta at 1.8 A Resolution. IMPLICATION FOR A SUBSTRATE SPECIFICITY J. Biol. Chem., March 16, 2001; 276(12): 9158 - 9165. [Abstract] [Full Text] [PDF]

				E. Mornet, E. Stura, A.-S. Lia-Baldini, T. Stigbrand, A. Menez, and M.-H. Le Du Structural Evidence for a Functional Role of Human Tissue Nonspecific Alkaline Phosphatase in Bone Mineralization J. Biol. Chem., August 10, 2001; 276(33): 31171 - 31178. [Abstract] [Full Text] [PDF]