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Huang X, Wang Y, Yu C, Zhang H, Ru Q, Li X, Song K, Zhou M, Zhu P. Cryo-EM structures reveal the dynamic transformation of human alpha-2-macroglobulin working as a protease inhibitor. SCIENCE CHINA. LIFE SCIENCES 2022; 65:2491-2504. [PMID: 35781771 DOI: 10.1007/s11427-022-2139-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/14/2022] [Accepted: 06/06/2022] [Indexed: 10/17/2022]
Abstract
Human alpha-2-macroglobulin is a well-known inhibitor of a broad spectrum of proteases and plays important roles in immunity, inflammation, and infections. Here, we report the cryo-EM structures of human alpha-2-macroglobulin in its native state, induced state transformed by its authentic substrate, human trypsin, and serial intermediate states between the native and fully induced states. These structures exhibit distinct conformations, which reveal the dynamic transformation of alpha-2-macro-globulin that acts as a protease inhibitor. The results shed light on the molecular mechanism of alpha-2-macroglobulin in entrapping substrates.
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Affiliation(s)
- Xiaoxing Huang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Youwang Wang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Cong Yu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Hui Zhang
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Qiang Ru
- The Institute of Medicinal Plant Development, Chinese Academy of Medical Sciences (CAMS) and Peking Union Medical College (PUMC), Beijing, 100193, China
| | - Xinxin Li
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.,University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Kai Song
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Min Zhou
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Ping Zhu
- National Laboratory of Biomacromolecules, CAS Center for Excellence in Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China. .,University of Chinese Academy of Sciences, Beijing, 100049, China.
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2
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Cryo-EM structures show the mechanistic basis of pan-peptidase inhibition by human α 2-macroglobulin. Proc Natl Acad Sci U S A 2022; 119:e2200102119. [PMID: 35500114 PMCID: PMC9181621 DOI: 10.1073/pnas.2200102119] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Human α2-macroglobulin (hα2M) is an ∼720-kDa homotetrameric particle with pan-peptidase inhibitory functions that transits between an open native conformation and a closed induced state, in which endopeptidases are trapped upon cleavage of an accessible bait region. We determined the molecular mechanism of this function through eight cryo–electron microscopy (cryo-EM) structures, which revealed that the hα2M subunits are organized in two flexible modules that undergo independent expanded-to-compact transitions. In the induced state, a reactive thioester bond triggers covalent linking of the proteinase, and a receptor-binding domain is exposed on the tetramer surface for binding to its specific cellular receptor for internalization and clearance from circulation. These results elucidate the long-awaited molecular mechanism of a historical suicidal inhibitory trap. Human α2-macroglobulin (hα2M) is a multidomain protein with a plethora of essential functions, including transport of signaling molecules and endopeptidase inhibition in innate immunity. Here, we dissected the molecular mechanism of the inhibitory function of the ∼720-kDa hα2M tetramer through eight cryo–electron microscopy (cryo-EM) structures of complexes from human plasma. In the native complex, the hα2M subunits are organized in two flexible modules in expanded conformation, which enclose a highly porous cavity in which the proteolytic activity of circulating plasma proteins is tested. Cleavage of bait regions exposed inside the cavity triggers rearrangement to a compact conformation, which closes openings and entraps the prey proteinase. After the expanded-to-compact transition, which occurs independently in the four subunits, the reactive thioester bond triggers covalent linking of the proteinase, and the receptor-binding domain is exposed on the tetramer surface for receptor-mediated clearance from circulation. These results depict the molecular mechanism of a unique suicidal inhibitory trap.
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3
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Structural Mechanics of the Alpha-2-Macroglobulin Transformation. J Mol Biol 2022; 434:167413. [PMID: 34942166 PMCID: PMC8897276 DOI: 10.1016/j.jmb.2021.167413] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/13/2021] [Accepted: 12/14/2021] [Indexed: 11/21/2022]
Abstract
Alpha-2-Macroglobulin (A2M) is the critical pan-protease inhibitor of the innate immune system. When proteases cleave the A2M bait region, global structural transformation of the A2M tetramer is triggered to entrap the protease. The structural basis behind the cleavage-induced transformation and the protease entrapment remains unclear. Here, we report cryo-EM structures of native- and intermediate-forms of the Xenopus laevis egg A2M homolog (A2Moo or ovomacroglobulin) tetramer at 3.7-4.1 Å and 6.4 Å resolution, respectively. In the native A2Moo tetramer, two pairs of dimers arrange into a cross-like configuration with four 60 Å-wide bait-exposing grooves. Each bait in the native form threads into an aperture formed by three macroglobulin domains (MG2, MG3, MG6). The bait is released from the narrowed aperture in the induced protomer of the intermediate form. We propose that the intact bait region works as a "latch-lock" to block futile A2M transformation until its protease-mediated cleavage.
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4
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Harwood SL, Lyngsø J, Zarantonello A, Kjøge K, Nielsen PK, Andersen GR, Pedersen JS, Enghild JJ. Structural Investigations of Human A2M Identify a Hollow Native Conformation That Underlies Its Distinctive Protease-Trapping Mechanism. Mol Cell Proteomics 2021; 20:100090. [PMID: 33964423 PMCID: PMC8167298 DOI: 10.1016/j.mcpro.2021.100090] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 04/07/2021] [Accepted: 05/02/2021] [Indexed: 12/21/2022] Open
Abstract
Human α2-macroglobulin (A2M) is the most characterized protease inhibitor in the alpha-macroglobulin (αM) superfamily, but the structure of its native conformation has not been determined. Here, we combined negative stain electron microscopy (EM), small-angle X-ray scattering (SAXS), and cross-linking-mass spectrometry (XL-MS) to investigate native A2M and its collapsed conformations that are obtained through aminolysis of its thiol ester by methylamine or cleavage of its bait region by trypsin. The combined interpretation of these data resulted in a model of the native A2M tetramer and its conformational changes. Native A2M consists of two crescent-shaped disulfide-bridged subunit dimers, which face toward each other and surround a central hollow space. In native A2M, interactions across the disulfide-bridged dimers are minimal, with a single major interface between the linker (LNK) regions of oppositely positioned subunits. Bait region cleavage induces both intrasubunit domain repositioning and an altered configuration of the disulfide-bridged dimer. These changes collapse the tetramer into a more compact conformation, which encloses an interior protease-trapping cavity. A recombinant A2M with a modified bait region was used to map the bait region's position in native A2M by XL-MS. A second recombinant A2M introduced an intersubunit disulfide into the LNK region, demonstrating the predicted interactions between these regions in native A2M. Altogether, our native A2M model provides a structural foundation for understanding A2M's protease-trapping mechanism, its conformation-dependent receptor interactions, and the dissociation of native A2M into dimers due to inflammatory oxidative stress.
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Affiliation(s)
- Seandean Lykke Harwood
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Global Research Technologies, Novo Nordisk A/S, Måløv, Denmark
| | - Jeppe Lyngsø
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark; Department of Chemistry, Aarhus University, Aarhus, Denmark
| | | | - Katarzyna Kjøge
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | | | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jan Skov Pedersen
- Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark; Department of Chemistry, Aarhus University, Aarhus, Denmark.
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark; Interdisciplinary Nanoscience Center, Aarhus University, Aarhus, Denmark.
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5
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Pihl R, Jensen RK, Poulsen EC, Jensen L, Hansen AG, Thøgersen IB, Dobó J, Gál P, Andersen GR, Enghild JJ, Thiel S. ITIH4 acts as a protease inhibitor by a novel inhibitory mechanism. SCIENCE ADVANCES 2021; 7:7/2/eaba7381. [PMID: 33523981 PMCID: PMC7793589 DOI: 10.1126/sciadv.aba7381] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/31/2019] [Accepted: 11/16/2020] [Indexed: 05/02/2023]
Abstract
Inter-α-inhibitor heavy chain 4 (ITIH4) is a poorly characterized plasma protein that is proteolytically processed in multiple pathological conditions. However, no biological function of ITIH4 has been identified. Here, we show that ITIH4 is cleaved by several human proteases within a protease-susceptible region, enabling ITIH4 to function as a protease inhibitor. This is exemplified by its inhibition of mannan-binding lectin-associated serine protease-1 (MASP-1), MASP-2, and plasma kallikrein, which are key proteases for intravascular host defense. Mechanistically, ITIH4 acts as bait that, upon cleavage, forms a noncovalent, inhibitory complex with the executing protease that depends on the ITIH4 von Willebrand factor A domain. ITIH4 inhibits the MASPs by sterically preventing larger protein substrates from accessing their active sites, which remain accessible and fully functional toward small substrates. Thus, we demonstrate that ITIH4 functions as a protease inhibitor by a previously undescribed inhibitory mechanism.
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Affiliation(s)
- Rasmus Pihl
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | - Rasmus K Jensen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Emil C Poulsen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Lisbeth Jensen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark
| | | | - Ida B Thøgersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - József Dobó
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Péter Gál
- Institute of Enzymology, Research Centre for Natural Sciences, Budapest, Hungary
| | - Gregers R Andersen
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Aarhus, Denmark
| | - Steffen Thiel
- Department of Biomedicine, Aarhus University, Aarhus, Denmark.
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6
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Parizi LF, Ali A, Tirloni L, Oldiges DP, Sabadin GA, Coutinho ML, Seixas A, Logullo C, Termignoni C, DA Silva Vaz I. Peptidase inhibitors in tick physiology. MEDICAL AND VETERINARY ENTOMOLOGY 2018; 32:129-144. [PMID: 29111611 DOI: 10.1111/mve.12276] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 06/23/2017] [Accepted: 10/07/2017] [Indexed: 06/07/2023]
Abstract
Peptidase inhibitors regulate a wide range of physiological processes involved in the interaction between hematophagous parasites and their hosts, including tissue remodeling, the immune response and blood coagulation. In tick physiology, peptidase inhibitors have a crucial role in adaptation to improve parasitism mechanisms, facilitating blood feeding by interfering with defense-related host peptidases. Recently, a larger number of studies on this topic led to the description of several new tick inhibitors displaying interesting novel features, for example a role in pathogen transmission to the host. A comprehensive review discussing these emerging concepts can therefore shed light on peptidase inhibitor functions, their relevance to tick physiology and their potential applications. Here, we summarize and examine the general characteristics, functional diversity and action of tick peptidase inhibitors with known physiological roles in the tick-host-pathogen interaction.
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Affiliation(s)
- L F Parizi
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - A Ali
- Department of Zoology, Abdul Wali Khan University, Mardan, Pakistan
- Escola de Enfermagem de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil
| | - L Tirloni
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - D P Oldiges
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - G A Sabadin
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - M L Coutinho
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
| | - A Seixas
- Departamento de Farmacociências, Universidade Federal de Ciências da Saúde de Porto Alegre, RS, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - C Logullo
- Laboratório de Química e Função de Proteínas e Peptídeos-CBB and Unidade de Experimentação Animal, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - C Termignoni
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Departamento de Bioquímica, Universidade Federal do Rio Grande do Sul, Porto Alegre, Porto Alegre, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
| | - I DA Silva Vaz
- Centro de Biotecnologia, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Faculdade de Veterinária, Universidade Federal do Rio Grande do Sul, Porto Alegre, RS, Brazil
- Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, RJ, Brazil
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7
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Martos L, Ramón LA, Oto J, Fernández-Pardo Á, Bonanad S, Cid AR, Gruber A, Griffin JH, España F, Navarro S, Medina P. α2-Macroglobulin Is a Significant In Vivo Inhibitor of Activated Protein C and Low APC:α2M Levels Are Associated with Venous Thromboembolism. Thromb Haemost 2018; 118:630-638. [PMID: 29448296 PMCID: PMC6002867 DOI: 10.1055/s-0038-1629902] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
BACKGROUND Activated protein C (APC) is a major regulator of thrombin formation. Two major plasma inhibitors form complexes with APC, protein C inhibitor (PCI) and α1-antitrypsin (α1AT), and these complexes have been quantified by specific enzyme-linked immunosorbent assays (ELISAs). Also, complexes of APC with α2-macroglobulin (α2M) have been observed by immunoblotting. Here, we report an ELISA for APC:α2M complexes in plasma. METHODS Plasma samples were pre-treated with dithiothreitol and then with iodoacetamide. The detection range of the newly developed APC:α2M assay was 0.031 to 8.0 ng/mL of complexed APC. Following infusions of APC in humans and baboons, complexes of APC with α2M, PCI and α1AT were quantified. These complexes as well as circulating APC were also measured in 121 patients with a history of venous thromboembolism (VTE) and 119 matched controls. RESULTS In all the in vivo experiments, α2M was a significant APC inhibitor. The VTE case-control study showed that VTE patients had significantly lower APC:α2M and APC levels than the controls (p < 0.001). Individuals in the lowest quartile of APC:α2M or the lowest quartile of APC had approximately four times more VTE risk than those in the highest quartile of APC:α2M or of APC. The risk increased for individuals with low levels of both parameters. CONCLUSION The APC:α2M assay reported here may be useful to help monitor the in vivo fate of APC in plasma. In addition, our results show that a low APC:α2M level is associated with increased VTE risk.
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Affiliation(s)
- Laura Martos
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Luis Andrés Ramón
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Julia Oto
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Álvaro Fernández-Pardo
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Santiago Bonanad
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain,Unidad de Trombosis y Hemostasia, Servicio de Hematología, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Ana Rosa Cid
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain,Unidad de Trombosis y Hemostasia, Servicio de Hematología, Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Andras Gruber
- Department of Biomedical Engineering, Oregon Health and Science University, Portland, Oregon, United States
| | - John H. Griffin
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, United States
| | - Francisco España
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Silvia Navarro
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain
| | - Pilar Medina
- Grupo de Investigación en Hemostasia, Trombosis, Arteriosclerosis y Biología Vascular, Instituto de Investigación Sanitaria La Fe (IIS La Fe), Hospital Universitario y Politécnico La Fe, Valencia, Spain
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8
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Goulas T, Garcia-Ferrer I, Marrero A, Marino-Puertas L, Duquerroy S, Gomis-Rüth FX. Structural and functional insight into pan-endopeptidase inhibition by α2-macroglobulins. Biol Chem 2017; 398:975-994. [PMID: 28253193 DOI: 10.1515/hsz-2016-0329] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2016] [Accepted: 02/18/2017] [Indexed: 12/30/2022]
Abstract
Peptidases must be exquisitely regulated to prevent erroneous cleavage and one control is provided by protein inhibitors. These are usually specific for particular peptidases or families and sterically block the active-site cleft of target enzymes using lock-and-key mechanisms. In contrast, members of the +1400-residue multi-domain α2-macroglobulin inhibitor family (α2Ms) are directed against a broad spectrum of endopeptidases of disparate specificities and catalytic types, and they inhibit their targets without disturbing their active sites. This is achieved by irreversible trap mechanisms resulting from large conformational rearrangement upon cleavage in a promiscuous bait region through the prey endopeptidase. After decades of research, high-resolution structural details of these mechanisms have begun to emerge for tetrameric and monomeric α2Ms, which use 'Venus-flytrap' and 'snap-trap' mechanisms, respectively. In the former, represented by archetypal human α2M, inhibition is exerted through physical entrapment in a large cage, in which preys are still active against small substrates and inhibitors that can enter the cage through several apertures. In the latter, represented by a bacterial α2M from Escherichia coli, covalent linkage and steric hindrance of the prey inhibit activity, but only against very large substrates.
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9
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Masurier N, Arama DP, El Amri C, Lisowski V. Inhibitors of kallikrein-related peptidases: An overview. Med Res Rev 2017; 38:655-683. [DOI: 10.1002/med.21451] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2017] [Revised: 04/24/2017] [Accepted: 05/16/2017] [Indexed: 12/11/2022]
Affiliation(s)
- Nicolas Masurier
- Institut des Biomolécules Max Mousseron, UMR 5247, CNRS; Université de Montpellier, ENSCM, UFR des Sciences Pharmaceutiques et Biologiques; Montpellier Cedex France
| | - Dominique P. Arama
- Institut des Biomolécules Max Mousseron, UMR 5247, CNRS; Université de Montpellier, ENSCM, UFR des Sciences Pharmaceutiques et Biologiques; Montpellier Cedex France
| | - Chahrazade El Amri
- Sorbonne Universités, UPMC Univ Paris 06, UMR 8256; Biological Adaptation and Ageing, Integrated Cellular Ageing and Inflammation, Molecular & Functional Enzymology; Paris France
| | - Vincent Lisowski
- Institut des Biomolécules Max Mousseron, UMR 5247, CNRS; Université de Montpellier, ENSCM, UFR des Sciences Pharmaceutiques et Biologiques; Montpellier Cedex France
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10
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Abstract
α2-macroglobulins are broad-spectrum endopeptidase inhibitors, which have to date been characterised from metazoans (vertebrates and invertebrates) and Gram-negative bacteria. Their structural and biochemical properties reveal two related modes of action: the "Venus flytrap" and the "snap-trap" mechanisms. In both cases, peptidases trigger a massive conformational rearrangement of α2-macroglobulin after cutting in a highly flexible bait region, which results in their entrapment. In some homologs, a second action takes place that involves a highly reactive β-cysteinyl-γ-glutamyl thioester bond, which covalently binds cleaving peptidases and thus contributes to the further stabilization of the enzyme:inhibitor complex. Trapped peptidases are still active, but have restricted access to their substrates due to steric hindrance. In this way, the human α2-macroglobulin homolog regulates proteolysis in complex biological processes, such as nutrition, signalling, and tissue remodelling, but also defends the host organism against attacks by external toxins and other virulence factors during infection and envenomation. In parallel, it participates in several other biological functions by modifying the activity of cytokines and regulating hormones, growth factors, lipid factors and other proteins, which has a great impact on physiology. Likewise, bacterial α2-macroglobulins may participate in defence by protecting cell wall components from attacking peptidases, or in host-pathogen interactions through recognition of host peptidases and/or antimicrobial peptides. α2-macroglobulins are more widespread than initially thought and exert multifunctional roles in both eukaryotes and prokaryotes, therefore, their on-going study is essential.
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Affiliation(s)
- Irene Garcia-Ferrer
- Proteolysis Lab, Structural Biology Unit, "María de Maeztu" Unit of Excellence, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park; c/Baldiri Reixac, 15-21, 08028, Barcelona, Spain
- Present address: EMBL Grenoble, 71 Avenue des Martyrs; 38042 CS 90181, Grenoble Cedex 9, France
| | - Aniebrys Marrero
- Proteolysis Lab, Structural Biology Unit, "María de Maeztu" Unit of Excellence, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park; c/Baldiri Reixac, 15-21, 08028, Barcelona, Spain
- Present address: Department of Chemistry, University of Zürich, Winterthurerstrasse 190, 8057, Zurich, Switzerland
| | - F Xavier Gomis-Rüth
- Proteolysis Lab, Structural Biology Unit, "María de Maeztu" Unit of Excellence, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park; c/Baldiri Reixac, 15-21, 08028, Barcelona, Spain
| | - Theodoros Goulas
- Proteolysis Lab, Structural Biology Unit, "María de Maeztu" Unit of Excellence, Molecular Biology Institute of Barcelona (CSIC), Barcelona Science Park; c/Baldiri Reixac, 15-21, 08028, Barcelona, Spain.
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11
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De Matteis L, Di Renzo F, Germani R, Goracci L, Spreti N, Tiecco M. α-Chymotrypsin superactivity in quaternary ammonium salt solution: kinetic and computational studies. RSC Adv 2016. [DOI: 10.1039/c6ra07425a] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Ammonium salts determine an increase of the hydrophobicity of the α-chymotrypsin catalytic site and therefore an improvement of its activity.
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Affiliation(s)
- Laura De Matteis
- Department of Physical and Chemical Sciences
- University of L'Aquila
- I-67100 Coppito
- Italy
| | - Francesca Di Renzo
- Department of Physical and Chemical Sciences
- University of L'Aquila
- I-67100 Coppito
- Italy
| | - Raimondo Germani
- CEMIN, Centre of Excellence on Nanostructured Innovative Materials
- Department of Chemistry
- Biology and Biotechnology
- University of Perugia
- I-06123 Perugia
| | - Laura Goracci
- Laboratory for Chemoinformatics and Molecular Modelling
- Department of Chemistry
- Biology and Biotechnology
- University of Perugia
- I-06123 Perugia
| | - Nicoletta Spreti
- Department of Physical and Chemical Sciences
- University of L'Aquila
- I-67100 Coppito
- Italy
| | - Matteo Tiecco
- CEMIN, Centre of Excellence on Nanostructured Innovative Materials
- Department of Chemistry
- Biology and Biotechnology
- University of Perugia
- I-06123 Perugia
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12
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Structure of a bacterial α2-macroglobulin reveals mimicry of eukaryotic innate immunity. Nat Commun 2014; 5:4917. [DOI: 10.1038/ncomms5917] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 08/05/2014] [Indexed: 12/20/2022] Open
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13
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van Duijnhoven SMJ, Robillard MS, Nicolay K, Grüll H. In vivo biodistribution of radiolabeled MMP-2/9 activatable cell-penetrating peptide probes in tumor-bearing mice. CONTRAST MEDIA & MOLECULAR IMAGING 2014; 10:59-66. [PMID: 24823643 DOI: 10.1002/cmmi.1605] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Revised: 03/05/2014] [Accepted: 03/20/2014] [Indexed: 01/12/2023]
Abstract
Matrix metalloproteinases (MMPs) play a pivotal role in cancer progression and present therefore an interesting biomarker for early diagnosis, staging and therapy evaluation. Consequently, MMP-specific molecular imaging probes have been proposed for noninvasive visualization and quantification of MMP activity. An interesting approach is MMP-2/9 activatable cell-penetrating peptides (ACPP) that accumulate in the tumor tissue after activation. However, a recent study revealed that probe activation occurred already in the vasculature followed by nonspecific tumor targeting. In the latter study, biodistribution was determined 6 and 24 h post-ACPP injection. An alternative explanation could still be that the kinetics of tumor-specific activation is faster than that of blood activation plus subsequent nonspecific uptake in tumor. The aim of this study was to assess if tumor-specific ACPP activation occurs in mice with MMP-2/9 positive subcutaneous HT-1080 tumors at 3 h post-injection. As control, we studied the MMP-2/9 sensitive ACPP in mice bearing subcutaneous BT-20 tumors with low MMP-2/9 expression to test if probe cleavage correlates with tumoral MMP expression. Ex vivo biodistribution showed no improved tumoral ACPP activation in HT-1080 tumor-bearing mice at 3 h post-injection compared with previous reported data collected at 24 h post-injection. Furthermore, tumoral uptake and relative tumoral activation for ACPP were similar in both BT-20 and HT-1080 tumor-bearing mice. In conclusion, this study suggests that tumoral ACPP uptake in these tumor models originates from probe activation in the vasculature instead of tumor-specific MMP activation. Novel ACPPs that target tissue-specific proteases without nonspecific activation may unleash the full potential of the elegant ACPP concept.
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Affiliation(s)
- Sander M J van Duijnhoven
- Department of Biomedical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands; Center for Imaging Research and Education, Eindhoven, The Netherlands
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14
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Kim G, Weiss SJ, Levine RL. Methionine oxidation and reduction in proteins. BIOCHIMICA ET BIOPHYSICA ACTA 2014; 1840:901-5. [PMID: 23648414 PMCID: PMC3766491 DOI: 10.1016/j.bbagen.2013.04.038] [Citation(s) in RCA: 186] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Revised: 04/24/2013] [Accepted: 04/27/2013] [Indexed: 01/10/2023]
Abstract
BACKGROUND Cysteine and methionine are the two sulfur containing amino acids in proteins. While the roles of protein-bound cysteinyl residues as endogenous antioxidants are well appreciated, those of methionine remain largely unexplored. SCOPE We summarize the key roles of methionine residues in proteins. MAJOR CONCLUSION Recent studies establish that cysteine and methionine have remarkably similar functions. GENERAL SIGNIFICANCE Both cysteine and methionine serve as important cellular antioxidants, stabilize the structure of proteins, and can act as regulatory switches through reversible oxidation and reduction. This article is part of a Special Issue entitled Current methods to study reactive oxygen species - pros and cons and biophysics of membrane proteins. Guest Editor: Christine Winterbourn.
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Affiliation(s)
- Geumsoo Kim
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892, USA
| | - Stephen J. Weiss
- Division of Molecular Medicine and Genetics, Department of Internal Medicine, Life Sciences Institute, University of Michigan, Ann Arbor, MI 48109, USA
| | - Rodney L. Levine
- Laboratory of Biochemistry, National Heart, Lung, and Blood Institute, Bethesda, Maryland 20892, USA
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15
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Misra UK, Payne S, Pizzo SV. The Monomeric Receptor Binding Domain of Tetrameric α2-Macroglobulin Binds to Cell Surface GRP78 Triggering Equivalent Activation of Signaling Cascades. Biochemistry 2013; 52:4014-25. [DOI: 10.1021/bi400376s] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Uma Kant Misra
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, United
States
| | - Sturgis Payne
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, United
States
| | - Salvatore Vincent Pizzo
- Department of Pathology, Duke University Medical Center, Durham, North Carolina 27710, United
States
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16
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Neves D, Estrozi LF, Job V, Gabel F, Schoehn G, Dessen A. Conformational states of a bacterial α2-macroglobulin resemble those of human complement C3. PLoS One 2012; 7:e35384. [PMID: 22530012 PMCID: PMC3328433 DOI: 10.1371/journal.pone.0035384] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Accepted: 03/16/2012] [Indexed: 01/09/2023] Open
Abstract
α(2) macroglobulins (α(2)Ms) are broad-spectrum protease inhibitors that play essential roles in the innate immune system of eukaryotic species. These large, multi-domain proteins are characterized by a broad-spectrum bait region and an internal thioester, which, upon cleavage, becomes covalently associated to the target protease, allowing its entrapment by a large conformational modification. Notably, α(2)Ms are part of a larger protein superfamily that includes proteins of the complement system, such as C3, a multi-domain macromolecule which is also characterized by an internal thioester-carrying domain and whose activation represents the pivotal step in the complement cascade. Recently, α(2)M/C3-like genes were identified in a large number of bacterial genomes, and the Escherichia coli α(2)M homolog (ECAM) was shown to be activated by proteases. In this work, we have structurally characterized ECAM by electron microscopy and small angle scattering (SAXS) techniques. ECAM is an elongated, flexible molecule with overall similarities to C3 in its inactive form; activation by methylamine, chymotrypsin, or elastase induces a conformational modification reminiscent of the one undergone by the transformation of C3 into its active form, C3b. In addition, the proposed C-terminus of ECAM displays high flexibility and different conformations, and could be the recognition site for partner macromolecules. This work sheds light on a potential bacterial defense mechanism that mimics structural rearrangements essential for activation of the complement cascade in eukaryotes, and represents a possible novel target for the development of antibacterials.
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Affiliation(s)
- David Neves
- Institut de Biologie Structurale, Université Grenoble I, Grenoble, France.
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17
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Marrero A, Duquerroy S, Trapani S, Goulas T, Guevara T, Andersen GR, Navaza J, Sottrup-Jensen L, Gomis-Rüth FX. The Crystal Structure of Human α2-Macroglobulin Reveals a Unique Molecular Cage. Angew Chem Int Ed Engl 2012. [DOI: 10.1002/ange.201108015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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18
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Marrero A, Duquerroy S, Trapani S, Goulas T, Guevara T, Andersen GR, Navaza J, Sottrup-Jensen L, Gomis-Rüth FX. The Crystal Structure of Human α2-Macroglobulin Reveals a Unique Molecular Cage. Angew Chem Int Ed Engl 2012; 51:3340-4. [DOI: 10.1002/anie.201108015] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Indexed: 11/06/2022]
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19
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Affiliation(s)
- Christopher J Farady
- Graduate Group in Biophysics, University of California-San Francisco, San Francisco, CA 94143-2240, USA
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20
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Ozawa D, Hasegawa K, Lee YH, Sakurai K, Yanagi K, Ookoshi T, Goto Y, Naiki H. Inhibition of beta2-microglobulin amyloid fibril formation by alpha2-macroglobulin. J Biol Chem 2011; 286:9668-76. [PMID: 21216953 DOI: 10.1074/jbc.m110.167965] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The relationship between various amyloidoses and chaperones is gathering attention. In patients with dialysis-related amyloidosis, α(2)-macroglobulin (α2M), an extracellular chaperone, forms a complex with β(2)-microglobulin (β2-m), a major component of amyloid fibrils, but the molecular mechanisms and biological implications of the complex formation remain unclear. Here, we found that α2M substoichiometrically inhibited the β2-m fibril formation at a neutral pH in the presence of SDS, a model for anionic lipids. Binding analysis showed that the binding affinity between α2M and β2-m in the presence of SDS was higher than that in the absence of SDS. Importantly, SDS dissociated tetrameric α2M into dimers with increased surface hydrophobicity. Western blot analysis revealed that both tetrameric and dimeric α2M interacted with SDS-denatured β2-m. At a physiologically relevant acidic pH and in the presence of heparin, α2M was also dissociated into dimers, and both tetrameric and dimeric α2M interacted with β2-m, resulting in the inhibition of fibril growth reaction. These results suggest that under conditions where native β2-m is denatured, tetrameric α2M is also converted to dimeric form with exposed hydrophobic surfaces to favor the hydrophobic interaction with denatured β2-m, thus dimeric α2M as well as tetrameric α2M may play an important role in controlling β2-m amyloid fibril formation.
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Affiliation(s)
- Daisaku Ozawa
- Department of Pathological Sciences, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
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21
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Goettig P, Magdolen V, Brandstetter H. Natural and synthetic inhibitors of kallikrein-related peptidases (KLKs). Biochimie 2010; 92:1546-67. [PMID: 20615447 PMCID: PMC3014083 DOI: 10.1016/j.biochi.2010.06.022] [Citation(s) in RCA: 105] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 06/29/2010] [Indexed: 01/21/2023]
Abstract
Including the true tissue kallikrein KLK1, kallikrein-related peptidases (KLKs) represent a family of fifteen mammalian serine proteases. While the physiological roles of several KLKs have been at least partially elucidated, their activation and regulation remain largely unclear. This obscurity may be related to the fact that a given KLK fulfills many different tasks in diverse fetal and adult tissues, and consequently, the timescale of some of their physiological actions varies significantly. To date, a variety of endogenous inhibitors that target distinct KLKs have been identified. Among them are the attenuating Zn(2+) ions, active site-directed proteinaceous inhibitors, such as serpins and the Kazal-type inhibitors, or the huge, unspecific compartment forming α(2)-macroglobulin. Failure of these inhibitory systems can lead to certain pathophysiological conditions. One of the most prominent examples is the Netherton syndrome, which is caused by dysfunctional domains of the Kazal-type inhibitor LEKTI-1 which fail to appropriately regulate KLKs in the skin. Small synthetic inhibitory compounds and natural polypeptidic exogenous inhibitors have been widely employed to characterize the activity and substrate specificity of KLKs and to further investigate their structures and biophysical properties. Overall, this knowledge leads not only to a better understanding of the physiological tasks of KLKs, but is also a strong fundament for the synthesis of small compound drugs and engineered biomolecules for pharmaceutical approaches. In several types of cancer, KLKs have been found to be overexpressed, which makes them clinically relevant biomarkers for prognosis and monitoring. Thus, down regulation of excessive KLK activity in cancer and in skin diseases by small inhibitor compounds may represent attractive therapeutical approaches.
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Affiliation(s)
- Peter Goettig
- Division of Structural Biology, Department of Molecular Biology, University of Salzburg, Billrothstrasse 11, 5020 Salzburg, Austria.
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22
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Kantyka T, Rawlings ND, Potempa J. Prokaryote-derived protein inhibitors of peptidases: A sketchy occurrence and mostly unknown function. Biochimie 2010; 92:1644-56. [PMID: 20558234 DOI: 10.1016/j.biochi.2010.06.004] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Accepted: 06/08/2010] [Indexed: 11/28/2022]
Abstract
In metazoan organisms protein inhibitors of peptidases are important factors essential for regulation of proteolytic activity. In vertebrates genes encoding peptidase inhibitors constitute up to 1% of genes reflecting a need for tight and specific control of proteolysis especially in extracellular body fluids. In stark contrast unicellular organisms, both prokaryotic and eukaryotic consistently contain only few, if any, genes coding for putative peptidase inhibitors. This may seem perplexing in the light of the fact that these organisms produce large numbers of proteases of different catalytic classes with the genes constituting up to 6% of the total gene count with the average being about 3%. Apparently, however, a unicellular life-style is fully compatible with other mechanisms of regulation of proteolysis and does not require protein inhibitors to control their intracellular and extracellular proteolytic activity. So in prokaryotes occurrence of genes encoding different types of peptidase inhibitors is infrequent and often scattered among phylogenetically distinct orders or even phyla of microbiota. Genes encoding proteins homologous to alpha-2-macroglobulin (family I39), serine carboxypeptidase Y inhibitor (family I51), alpha-1-peptidase inhibitor (family I4) and ecotin (family I11) are the most frequently represented in Bacteria. Although several of these gene products were shown to possess inhibitory activity, with an exception of ecotin and staphostatins, the biological function of microbial inhibitors is unclear. In this review we present distribution of protein inhibitors from different families among prokaryotes, describe their mode of action and hypothesize on their role in microbial physiology and interactions with hosts and environment.
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Affiliation(s)
- Tomasz Kantyka
- Department of Microbiology, Jagiellonian University, Krakow, Poland
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23
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Raymond WW, Su S, Makarova A, Wilson TM, Carter MC, Metcalfe DD, Caughey GH. Alpha 2-macroglobulin capture allows detection of mast cell chymase in serum and creates a reservoir of angiotensin II-generating activity. THE JOURNAL OF IMMUNOLOGY 2009; 182:5770-7. [PMID: 19380825 DOI: 10.4049/jimmunol.0900127] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Human chymase is a highly efficient angiotensin II-generating serine peptidase expressed by mast cells. When secreted from degranulating cells, it can interact with a variety of circulating antipeptidases, but is mostly captured by alpha(2)-macroglobulin, which sequesters peptidases in a cage-like structure that precludes interactions with large protein substrates and inhibitors, like serpins. The present work shows that alpha(2)-macroglobulin-bound chymase remains accessible to small substrates, including angiotensin I, with activity in serum that is stable with prolonged incubation. We used alpha(2)-macroglobulin capture to develop a sensitive, microtiter plate-based assay for serum chymase, assisted by a novel substrate synthesized based on results of combinatorial screening of peptide substrates. The substrate has low background hydrolysis in serum and is chymase-selective, with minimal cleavage by the chymotryptic peptidases cathepsin G and chymotrypsin. The assay detects activity in chymase-spiked serum with a threshold of approximately 1 pM (30 pg/ml), and reveals native chymase activity in serum of most subjects with systemic mastocytosis. alpha(2)-Macroglobulin-bound chymase generates angiotensin II in chymase-spiked serum, and it appears in native serum as chymostatin-inhibited activity, which can exceed activity of captopril-sensitive angiotensin-converting enzyme. These findings suggest that chymase bound to alpha(2)-macroglobulin is active, that the complex is an angiotensin-converting enzyme inhibitor-resistant reservoir of angiotensin II-generating activity, and that alpha(2)-macroglobulin capture may be exploited in assessing systemic release of secreted peptidases.
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Affiliation(s)
- Wilfred W Raymond
- Cardiovascular Research Institute, University of California at San Francisco, San Francisco, CA 94143, USA
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24
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Fredslund F, Jenner L, Husted LB, Nyborg J, Andersen GR, Sottrup-Jensen L. The Structure of Bovine Complement Component 3 Reveals the Basis for Thioester Function. J Mol Biol 2006; 361:115-27. [PMID: 16831446 DOI: 10.1016/j.jmb.2006.06.009] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2006] [Revised: 06/01/2006] [Accepted: 06/06/2006] [Indexed: 11/25/2022]
Abstract
The third component of complement (C3) is a 190 kDa glycoprotein essential for eliciting the complement response. The protein consists of two polypeptide chains (alpha and beta) held together with a single disulfide bridge. The beta-chain is composed of six MG domains, one of which is shared with the alpha-chain. The disulfide bridge connecting the chains is positioned in the shared MG domain. The alpha-chain consists of the anaphylatoxin domain, three MG domains, a CUB domain, an alpha(6)/alpha(6)-barrel domain and the C-terminal C345c domain. An internal thioester in the alpha-chain of C3 (present in C4 but not in C5) is cleaved during complement activation. This mediates covalent attachment of the activated C3b to immune complexes and invading microorganisms, thereby opsonizing the target. We present the structure of bovine C3 determined at 3 Angstroms resolution. The structure shows that the ester is buried deeply between the thioester domain and the properdin binding domain, in agreement with the human structure. This domain interface is broken upon activation, allowing nucleophile access. The structure of bovine C3 clearly demonstrates that the main chain around the thioester undergoes a helical transition upon activation. This rearrangement is proposed to be the basis for the high level of reactivity of the thioester group. A strictly conserved glutamate residue is suggested to function catalytically in thioester proteins. Structure-based design of inhibitors of C3 activation may target a conserved pocket between the alpha-chain and the beta-chain of C3, which appears essential for conformational changes in C3.
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25
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Arnold JN, Wallis R, Willis AC, Harvey DJ, Royle L, Dwek RA, Rudd PM, Sim RB. Interaction of Mannan Binding Lectin with α2 Macroglobulin via Exposed Oligomannose Glycans. J Biol Chem 2006; 281:6955-63. [PMID: 16407218 DOI: 10.1074/jbc.m511432200] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The serum collectin mannan-binding lectin (MBL) binds to oligomannose and GlcNAc-terminating glycans present on microorganisms. Using a commercial affinity chromatography resin containing immobilized MBL we screened human and mouse serum for endogenous MBL-binding targets. We isolated the serum protease inhibitor alpha(2) macroglobulin (alpha2M), a heavily glycosylated thiol ester protein (TEP) composed of four identical 180-kDa subunits, each of which has eight N-linked glycosylation sites. alpha2M has previously been reported to interact with MBL; however, the interaction was not characterized. We investigated the mechanism of formation of complexes between alpha2M and MBL and concluded that they form by the direct binding of oligomannose glycans Man(5-7) occupying Asn-846 on alpha2M to the lectin domains (carbohydrate recognition domains) of MBL. The oligomannose glycans are accessible for lectin binding on both active alpha2M (thiol ester intact) and protease-cleaved alpha2M (thiol ester cleaved). We demonstrate that MBL is able to interact with alpha2M in the fluid phase, but the interaction does not inhibit the binding of MBL to mannan-coated surfaces. In addition to alpha2M, two other members of the TEP family, C3 and C4, which also contain oligomannose glycans, were captured from human serum using the MBL resin. MBL binding may be a conserved feature of the TEPs, dating from their ancestral origins. We suggest that the inhibition of proteases on the surface of microorganisms by an ancestral alpha2M-like TEP may generate "arrays" of oligomannose glycans to which MBL or other lectins can bind. Binding would lead to opsonization or activation of enzyme systems such as complement.
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Affiliation(s)
- James N Arnold
- Medical Research Council Immunochemistry Unit and Oxford Glycobiology Institute, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, England
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26
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Klein G, Vellenga E, Fraaije MW, Kamps WA, de Bont ESJM. The possible role of matrix metalloproteinase (MMP)-2 and MMP-9 in cancer, e.g. acute leukemia. Crit Rev Oncol Hematol 2004; 50:87-100. [PMID: 15157658 DOI: 10.1016/j.critrevonc.2003.09.001] [Citation(s) in RCA: 265] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/01/2003] [Indexed: 12/12/2022] Open
Abstract
In the past decades, a lot of effort has been put in identifying the role of matrix metalloproteinases (MMPs) in cancer. The main role of MMPs in angiogenesis, tumor growth and metastasis is degradation of extracellular matrix (ECM) and release and/or activation of growth factors through their degradative activity. The degradative activity finally results in cancer progression. MMP-inhibitors (MMPIs) have already been designed and tested, based on the degradative role of MMPs in cancer progression. First clinical trials with MMPIs have been performed with disappointing results, showing that in order to use MMP-inhibition the mechanisms underlying MMP-expression in cancer have to be further elucidated. This paper reviews the mechanisms of MMPs on molecular and cellular level and discusses the role for MMPs and MMP-inhibition in cancer with special focus on acute leukemia.
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Affiliation(s)
- G Klein
- Division of Pediatric Oncology and Hematology, Beatrix Children's Hospital, Groningen University Hospital, Hanzeplein 1, P.O. Box 30.001, Groningen 9700 RB, The Netherlands
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27
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Gaden F, Franqueville L, Magnusson MK, Hong SS, Merten MD, Lindholm L, Boulanger P. Gene transduction and cell entry pathway of fiber-modified adenovirus type 5 vectors carrying novel endocytic peptide ligands selected on human tracheal glandular cells. J Virol 2004; 78:7227-47. [PMID: 15194799 PMCID: PMC421659 DOI: 10.1128/jvi.78.13.7227-7247.2004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Monolayers of cystic fibrosis transmembrane conductance regulator (CFTR)-deficient human tracheal glandular cells (CF-KM4) were subjected to phage biopanning, and cell-internalized phages were isolated and sequenced, in order to identify CF-KM4-specific peptide ligands that would confer upon adenovirus type 5 (Ad5) vector a novel cell target specificity and/or higher efficiency of gene delivery into airway cells of patients with cystic fibrosis (CF). Three different ligands, corresponding to prototypes of the most represented families of phagotopes recovered from intracellular phages, were designed and individually inserted into Ad5-green fluorescent protein (GFP) (AdGFP) vectors at the extremities of short fiber shafts (seven repeats [R7]) terminated by scissile knobs. Only one vector, carrying the decapeptide GHPRQMSHVY (abbreviated as QM10), showed an enhanced gene transduction of CF-KM4 cells compared to control nonliganded vector with fibers of the same length (AdGFP-R7-knob). The enhancement in gene transfer efficiency was not specific to CF-KM4 cells but was observed in other mammalian cell lines tested. The QM10-liganded vector was referred to as AdGFP-QM10-knob in its knobbed version and as AdGFP-QM10 in its proteolytically deknobbed version. AdGFP-QM10 was found to transduce cells with a higher efficiency than its knob-bearing version, AdGFP-QM10-knob. Consistent with this, competition experiments indicated that the presence of knob domains was not an absolute requirement for cell attachment of the QM10-liganded vector and that the knobless AdGFP-QM10 used alternative cell-binding domains on its capsid, including penton base capsomer, via a site(s) different from its RGD motifs. The QM10-mediated effect on gene transduction seemed to take place at the step of endocytosis in both quantitative and qualitative manners. Virions of AdGFP-QM10 were endocytosed in higher numbers than virions of the control vector and were directed to a compartment different from the early endosomes targeted by members of species C Ad. AdGFP-QM10 was found to accumulate in late endosomal and low-pH compartments, suggesting that QM10 acted as an endocytic ligand of the lysosomal pathway. These results validated the concept of detargeting and retargeting Ad vectors via our deknobbing system and redirecting Ad vectors to an alternative endocytic pathway via a peptide ligand inserted in the fiber shaft domain.
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Affiliation(s)
- Florence Gaden
- Laboratoire de Virologie et Pathogénèse Virale, Faculté de Médecine de Lyon, and Insititut Fédératif de Recherche RTH Laennec, 6372 Lyon, France
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28
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Rawlings ND, Tolle DP, Barrett AJ. Evolutionary families of peptidase inhibitors. Biochem J 2004; 378:705-16. [PMID: 14705960 PMCID: PMC1224039 DOI: 10.1042/bj20031825] [Citation(s) in RCA: 401] [Impact Index Per Article: 20.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2003] [Revised: 12/23/2003] [Accepted: 01/05/2004] [Indexed: 12/13/2022]
Abstract
The proteins that inhibit peptidases are of great importance in medicine and biotechnology, but there has never been a comprehensive system of classification for them. Some of the terminology currently in use is potentially confusing. In the hope of facilitating the exchange, storage and retrieval of information about this important group of proteins, we now describe a system wherein the inhibitor units of the peptidase inhibitors are assigned to 48 families on the basis of similarities detectable at the level of amino acid sequence. Then, on the basis of three-dimensional structures, 31 of the families are assigned to 26 clans. A simple system of nomenclature is introduced for reference to each clan, family and inhibitor. We briefly discuss the specificities and mechanisms of the interactions of the inhibitors in the various families with their target enzymes. The system of families and clans of inhibitors described has been implemented in the MEROPS peptidase database (http://merops.sanger.ac.uk/), and this will provide a mechanism for updating it as new information becomes available.
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Affiliation(s)
- Neil D Rawlings
- The Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire CB10 1SA, UK.
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29
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Hope C, Mettenburg J, Gonias SL, DeKosky ST, Kamboh MI, Chu CT. Functional analysis of plasma α2-macroglobulin from Alzheimer's disease patients with the A2M intronic deletion. Neurobiol Dis 2003; 14:504-12. [PMID: 14678766 DOI: 10.1016/j.nbd.2003.08.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
alpha(2)-Macroglobulin (alpha(2)M) is an abundant plasma/extracellular space protein implicated in clearance of amyloid beta (Abeta), a key constituent of Alzheimer's disease (AD) plaques. alpha(2)M also regulates proteinase and growth factor activities. In recent years, there have been >30 genetic studies debating the controversial role of a five-base-pair intronic deletion in the A2M gene in late-onset AD. However, little is known about potential effects of the deletion upon alpha(2)M function. In this study, we examined the subunit and conformational structure of alpha(2)M in AD plasma samples, and its capacity to bind trypsin, transforming growth factor-beta1, and Abeta. Plasma from patients homozygous for the deletion (DD) showed normal alpha(2)M subunit size, conformation, and proteinase inhibitory activity. Interestingly, plasma alpha(2)M from two DD patients showed markedly increased TGF-beta1 binding. Moreover, methylamine-treated DD plasma samples showed modest, but significant, elevations in Abeta binding to alpha(2)M* compared with samples from patients lacking the deletion. These observations suggest a possible functional basis by which the A2M deletion may influence multifactorial AD pathogenesis.
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Affiliation(s)
- Caroline Hope
- Department of Pathology, University of Pittsburgh, Pittsburgh, PA 15213, USA
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30
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Freije JR, Bischoff R. Activity-based enrichment of matrix metalloproteinases using reversible inhibitors as affinity ligands. J Chromatogr A 2003; 1009:155-69. [PMID: 13677656 DOI: 10.1016/s0021-9673(03)00920-8] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Matrix metalloproteinases (MMPs) are zinc dependent metalloproteases characterized by the ability to cleave extracellular matrix and many other extracellular proteins. MMP activity is tightly regulated but disturbances in this regulation can contribute to various disease processes characterized by a progressive destruction of the extracellular matrix. The ability to profile classes of enzymes based on functionally related activities would greatly facilitate research about the involvement of MMPs in physiological and/or pathological states. Here we describe the characterization of an affinity sorbent using an immobilized reversible inhibitor as a stationary phase for the activity-based enrichment of MMPs from biological samples. With a ligand density of 9.8 mM and binding constant of 58 micromol/l towards MMP-12, the capturing power of the affinity sorbent was strong enough to extract MMP-12 spiked into serum with high selectivity from relatively large sample volumes. Experiments with endogenous inhibitors revealed that MMP-12 extraction is strictly activity-dependent, offering powerful means to monitor MMP activities in relation to physiological and/or pathological events by using affinity extraction as a first step in an MMP profiling method.
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Affiliation(s)
- J R Freije
- University Center for Pharmacy, University of Groningen, Antonius Deusinglaan 1, 9713 AV Groningen, The Netherlands
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