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 Nash, P. Articles by McFadden, G. Search for Related Content PubMed PubMed Citation Articles by Nash, P. Articles by McFadden, G. Social Bookmarking                      What's this?

J Biol Chem, Vol. 273, Issue 33, 20982-20991, August 14, 1998

Inhibitory Specificity of the Anti-inflammatory Myxoma Virus Serpin, SERP-1

Piers Nash^§, Adrian Whitty, Jason Handwerker, Joanne Macen, and Grant McFadden^§

From the  Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada,  Protein Engineering Department, Biogen Inc., Cambridge, Massachusetts 02142, and the ^§ Department of Microbiology and Immunology, University of Western Ontario and The J. P. Robarts Research Institute, London, Ontario N6G 2V4, Canada

SERP-1 is a myxoma virus-encoded serpin, secreted from infected cells, that is required for virulence and has anti-inflammatory activity. We report that purified recombinant SERP-1 forms SDS-stable complexes with urokinase-type plasminogen activator (uPA), tissue-type plasminogen activator (tPA), plasmin, thrombin, and factor Xa. N-terminal sequencing confirmed Arg³¹⁹-Asn³²⁰ as the site of reaction. Mutation of these residues to Ala-Ala abolished inhibitory activity but had no effect on the specific cleavage at Thr³¹⁵-Leu³¹⁶ seen with elastase and with cathepsin G. Kinetic analysis of the reactions with uPA, tPA, plasmin, thrombin, Xa, and C1s showed second-order rate constants to vary over 3 logs, from k_inh = 3 × 10⁵ M¹ s¹ with thrombin to ~600 M¹ s¹ with C1s, while steady-state inhibition constants ranged from K_I = 10 pM with thrombin to ~100 nM with C1s. Stoichiometries of inhibition varied between SI = 1.4 ± 0.1 for uPA to SI = 13 ± 3 for thrombin. Analysis of the variations in inhibition kinetics shows that when serpins act at low concentrations, comparable with the target protease or with K_I (as appears likely for SERP-1 in vivo), inhibitory specificity becomes less dominated by k_inh and is increasingly dependent on partitioning within the branched reaction mechanism and on the lifetime of the inhibited complex.

CiteULike

Complore

Connotea

Del.icio.us

Digg

Reddit

Technorati

This article has been cited by other articles:

				S. J. Werden, J. W. Barrett, G. Wang, M. M. Stanford, and G. McFadden M-T5, the Ankyrin Repeat, Host Range Protein of Myxoma Virus, Activates Akt and Can Be Functionally Replaced by Cellular PIKE-A J. Virol., March 1, 2007; 81(5): 2340 - 2348. [Abstract] [Full Text] [PDF]

				E. Dai, K. Viswanathan, Y. M. Sun, X. Li, L. Y. Liu, B. Togonu-Bickersteth, J. Richardson, C. Macaulay, P. Nash, P. Turner, et al. Identification of Myxomaviral Serpin Reactive Site Loop Sequences That Regulate Innate Immune Responses J. Biol. Chem., March 24, 2006; 281(12): 8041 - 8050. [Abstract] [Full Text] [PDF]

				G. Wang, J. W. Barrett, M. Stanford, S. J. Werden, J. B. Johnston, X. Gao, M. Sun, J. Q. Cheng, and G. McFadden Infection of human cancer cells with myxoma virus requires Akt activation via interaction with a viral ankyrin-repeat host range factor PNAS, March 21, 2006; 103(12): 4640 - 4645. [Abstract] [Full Text] [PDF]

				A. Lucas and G. McFadden Secreted Immunomodulatory Viral Proteins as Novel Biotherapeutics J. Immunol., October 15, 2004; 173(8): 4765 - 4774. [Abstract] [Full Text] [PDF]

				A. Mullick, M. Elias, P. Harakidas, A. Marcil, M. Whiteway, B. Ge, T. J. Hudson, A. W. Caron, L. Bourget, S. Picard, et al. Gene Expression in HL60 Granulocytoids and Human Polymorphonuclear Leukocytes Exposed to Candida albicans{dagger} Infect. Immun., January 1, 2004; 72(1): 414 - 429. [Abstract] [Full Text] [PDF]

				I. Bot, J. H. von der Thusen, M. M.P.C. Donners, A. Lucas, M. L. Fekkes, S. C.A. de Jager, J. Kuiper, M. J.A.P. Daemen, T. J.C. van Berkel, S. Heeneman, et al. Serine Protease Inhibitor Serp-1 Strongly Impairs Atherosclerotic Lesion Formation and Induces a Stable Plaque Phenotype in ApoE-/- Mice Circ. Res., September 5, 2003; 93(5): 464 - 471. [Abstract] [Full Text] [PDF]

				E. Dai, H. Guan, L. Liu, S. Little, G. McFadden, S. Vaziri, H. Cao, I. A. Ivanova, L. Bocksch, and A. Lucas Serp-1, a Viral Anti-inflammatory Serpin, Regulates Cellular Serine Proteinase and Serpin Responses to Vascular Injury J. Biol. Chem., May 9, 2003; 278(20): 18563 - 18572. [Abstract] [Full Text] [PDF]

				M. T. Morris, A. Coppin, S. Tomavo, and V. B. Carruthers Functional Analysis of Toxoplasma gondii Protease Inhibitor 1 J. Biol. Chem., November 15, 2002; 277(47): 45259 - 45266. [Abstract] [Full Text] [PDF]

				T. Sulikowski, B. A. Bauer, and P. A. Patston {alpha}1-Proteinase inhibitor mutants with specificity for plasma kallikrein and C1s but not C1 Protein Sci., September 1, 2002; 11(9): 2230 - 2236. [Abstract] [Full Text] [PDF]

				J.-L. Guerin, J. Gelfi, C. Camus, M. Delverdier, J. C. Whisstock, M.-F. Amardeihl, R. Py, S. Bertagnoli, and F. Messud-Petit Characterization and functional analysis of Serp3: a novel myxoma virus-encoded serpin involved in virulence J. Gen. Virol., June 1, 2001; 82(6): 1407 - 1417. [Abstract] [Full Text]

				L. W. Miller, E. Dai, P. Nash, L. Liu, C. Icton, D. Klironomos, L. Fan, P. N. Nation, R. Zhong, G. McFadden, et al. Inhibition of Transplant Vasculopathy in a Rat Aortic Allograft Model After Infusion of Anti-Inflammatory Viral Serpin Circulation, April 4, 2000; 101(13): 1598 - 1605. [Abstract] [Full Text] [PDF]