DOCSLIB.ORG

C3did PNAS Pure

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
C3did PNAS Pure Structure of the CR3 I domain in complex with C3d Structural insight on the recognition of surface-bound opsonins by the integrin I domain of complement receptor 3 Goran Bajic1, Laure Yatime1, Robert B. Sim2, Thomas Vorup-Jensen3†, and Gregers R. Andersen1,† 1Dept. of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C, DK- 8000 Aarhus, Denmark 2Dept. of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom 3Dept. of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000 Aarhus, Denmark †Contact: Dr. Thomas Vorup-Jensen, Biophysical Immunology Laboratory, Dept. of Biomedicine, Aarhus University, Wilhelm Meyers Allé 4, DK-8000 Aarhus, Denmark. Tel: +45 87167853; E-mail: [email protected] Dr. Gregers R. Andersen, Dept. of Molecular Biology and Genetics , Aarhus University, Gustav Wieds Vej 10C, DK-8000 Aarhus, Denmark. Tel: +45 87 15 55 07; E-mail: [email protected] 1 Structure of the CR3 I domain in complex with C3d Complement receptors (CR), expressed notably on myeloid and lymphoid cells, play an essential function in the elimination of complement-opsonized pathogens and apoptotic/necrotic cells. In addition, these receptors are crucial for the cross-talk between the innate and adaptive branches of the immune system. CR3 (also known as Mac-1, integrin M2, or CD11b/CD18) is expressed on all macrophages and recognizes iC3b on complement-opsonized objects, enabling their phagocytosis. We demonstrate that the C3d moiety of iC3b harbours the binding site for the CR3 I domain, and our structure of the C3d:I domain complex rationalizes the CR3 selectivity for iC3b. Based on extensive structural analysis, we suggest that the choice between a ligand glutamate or aspartate for coordination of a receptor MIDAS-bound metal ion is governed by the secondary structure of the ligand. Comparison of our structure to the CR2:C3d complex and the in vitro formation of a stable CR3:C3d:CR2 complex suggests a molecular mechanism for the hand-over of CR3-bound immune complexes from macrophages to CR2-presenting cells in lymph nodes. Significance: Fragments of complement component C3 tag surfaces such as those presented by microbial pathogens or dying host cells for recognition by cells from the innate immune system. Complement receptor (CR) 3 enables efficient binding of complement-tagged surfaces by macrophages and dendritic cells, which eventually transport the CR3-bound material into lymph nodes. The study identifies in atomic detail the fragments of CR3 and C3 required for such binding. The structural organization permits concomitant recognition by another complement receptor, namely CR2, expressed on cells of the adaptive immune system, suggesting a structural rationale for exchange of antigens between leukocytes of the innate and adaptive immune systems critical in the formation of humoral immune responses. 2 Structure of the CR3 I domain in complex with C3d \body Activation of complement leads to proteolytic cleavage of the central complement component, C3. Its major fragment C3b acts as an opsonin and becomes covalently bound to the activating surface via a reactive thioester located in the thioester (TE) domain of nascent C3b (Fig. S1A). Proteolytic processing by factor I within the CUB domain of C3b leads to the formation of iC3b and C3dg. Finally C3d – which practically corresponds to the TE domain present in C3, C3b and iC3b (Fig. S1B-G) – is formed by other plasma proteases. These activation products are ligands for five complement receptors (1), with iC3b being the primary ligand of CR3 and CR4 (also known as CD11c/CD18, p150,95, or integrin X2 which is structurally similar to CR3. As other integrins, CR3 is a heterodimeric complex of two transmembrane proteins, M and 2. It is abundantly expressed on myeloid leukocytes, including neutrophil granulocytes, dendritic cells, monocytes, and macrophages and also on lymphoid NK cells (2). Most ligands, including iC3b (3), are bound by the Von Willebrand Factor A (VWA) domain in the -chain, also referred to as the I domain due to its insertion in the -propeller domain. I domain residues coordinate a metal ion essential for ligand recognition through a metal ion- dependent adhesion site (MIDAS). Integrins adopt at least three major conformations in the cell membrane. The bent-closed conformation is inactive in ligand binding, the extended- closed conformation has low ligand affinity, and the extended-open conformation binds ligands with high affinity. The transition from the bent-closed to the open-extended conformation is exerted by a cytoplasmic force on the leg of the -subunit, a process usually referred to as the inside-out signaling (4). 3 Structure of the CR3 I domain in complex with C3d Binding of ligands to CR3 leads to conformational changes in its ectodomain transmitting an outside-in signal through the cell membrane. This may lead to actin remodeling, phagocytosis, degranulation, and changes in leukocyte cytokine production (2, 5-7). CR3, and to a lesser degree CR4, are essential for the phagocytosis of complement-opsonized particles or complexes (6, 8, 9). Complement-opsonized immune complexes are captured in the lymph nodes by CR3-positive subcapsular sinus macrophages (SSM) and conveyed directly to naïve B cells or through follicular dendritic cells (10) utilizing CR1, CR2 and Fc receptors for antigen capture (11, 12) . Hence, antigen-presenting cells such as SSM may act as antigen storage and provide B lymphocytes with antigens (10, 12). Here, we establish the C3d fragment as the minimal and high-affinity binding partner for the CR3 I domain. By contrast, the binding site for the CR4 I domain was located in the C3c fragment by electron microscopy (13). We present the crystal structure of the CR3 I domain in complex with C3d. The classic observation of CR3 binding to iC3b, but not to its precursor C3b (14), is consistent with our structure. In addition, our structure and functional data suggest simultaneous binding of CR3 and another complement receptor, CR2, to C3 fragments, which might provide the basis for trafficking of complement-opsonized immune complexes from macrophages to B-cells and follicular dendritic cells in lymph nodes. RESULTS CR3 and CR4 I domains recognize distinct binding sites in iC3b. To quantitatively compare binding properties of the CR3 and CR4 I domain with regard to binding of C3 proteolytic fragments, C3b, iC3b, C3c, C3dg, and C3d were immobilized in surface plasmon resonance (SPR) flow cells. For both I domains good binding signals were observed with C3b, iC3b, and C3c as ligands (Fig. S2A-C & F-H). Nevertheless, even high concentrations 4 Structure of the CR3 I domain in complex with C3d (100 μM) of the CR3 or CR4 I domain did not lead to saturation. This is consistent with X-ray crystallography (15) and inhibition experiments showing that both the CR3 and CR4 I domain interact weakly (KD ~ 300 M) with acidic side chains acting as ligand mimetics (16). The C3d and C3dg-coated surfaces produced robust SPR signals (~1200 RU) and showed signs of saturation at high CR3 I domain concentrations (Fig. S2D,E). By contrast, the CR4 I domain only poorly bound these fragments (Fig. S2I,J). As detailed in other studies (16, 17), the binding kinetics of the CR3 and CR4 I domain ligand binding are not well-described with simple 1:1 Langmuir isotherms. The interactions were quantified by analysis of the sensorgrams with the EVILFIT algorithm, which calculates the minimal distribution in binding kinetics for the heterogeneous interactions with ligands (Fig. 1). In general, the modeled distribution in kinetics efficiently described the experimental data as reflected in the small root-mean-square deviations (RMSD). For the CR3 and CR4 I domain, some of the -4 -3 interactions with C3b, iC3b, and C3c were of modest strength with KD ~10 -10 M (Fig. 1A- B, & D-F), i.e., quantitatively equivalent to binding of acidic side chains reported earlier (16). -7 However, the classic CR3 ligand iC3b presented a population of interactions with KD ~10 - 10-6 M (Fig. 1B), not found with either C3b or C3c or for any fragments probed with the CR4 I domain (Fig. S3). This high-affinity type of interaction dominated the binding of the CR3 I domain to C3dg and C3d (Fig. 1 and Fig S3). Crystal structure of CR3 I domain in complex with C3d. Guided by the quantitative investigations made above, we determined the crystal structure of the CR3 I domain (subunit M residues 127-321, mature numbering) in complex with C3d (C3 residues 993-1288, prepro numbering) at 2.8 Å resolution (Table S1 and Fig. S4A). The structure reveals a 1:1 complex between the CR3 I domain and C3d (Fig. 2A). The integrin I domain folds into an α/β Rossmann fold and adopts its open conformation as shown by comparison with the open- 5 Structure of the CR3 I domain in complex with C3d conformation structure of the I domain (Fig S4B). The I domain α7 helix is shifted towards its C-terminus, and this conformation is most likely favoured by the I316G mutation introduced for this purpose. The open conformation is likewise adopted in the MIDAS site, where the hexa-coordinated metal ion is coordinated by Ser142, Ser144, Thr209 and two water molecules (Fig. 2B), whereas the last coordination position is occupied by an aspartate from C3d. As Mg2+ was not compatible with the electron density in the MIDAS site, and since Ni2+ was present in the crystallization buffer, we used anomalous diffraction data to confirm the presence of a Ni2+ ion in the MIDAS site (Fig. 2B and Table S1). The ability of Ni2+ to stabilize MIDAS interactions with a ligand is well known from the complement convertases (18). Within the complex, C3d adopts the well-described compact α-α6 barrel structure (Fig.
Load more

Recommended publications
  • Characterization of Kindlin3 in Integrin Functions
    This document is downloaded from DR‑NTU (https://dr.ntu.edu.sg) Nanyang Technological University, Singapore. Characterization of kindlin3 in Integrin functions Feng, Chen 2013 Feng, C. (2013). Characterization of kindlin3 in Integrin functions. Doctoral thesis, Nanyang Technological University, Singapore. https://hdl.handle.net/10356/54828 https://doi.org/10.32657/10356/54828 Downloaded on 27 Sep 2021 23:43:18 SGT Characterization of kindlin3 in Integrin functions Feng Chen School of Biological Sciences 2013 Characterization of kindlin3 in Integrin functions Feng Chen School of Biological Sciences A thesis submitted to the Nanyang Technological University in partial fulfillment of the requirement for the degree of Doctor of Philosophy 2013 Acknowledgements First, I would like to thank my supervisor Dr. Tan Suet Mien, for his guidance during the course of my studies. He gave me many helpful suggestions for my project and has been supportive of me for trying out new ideas. I’m grateful to Dr. Yau Yin Hoe and Assoc Prof. Shochat for helping me with the SPR analyses. I wish to thank my lab mates Man Li, Yan Feng, Zhi Hong, Xiao Yan, Rhoda, Henni, Sze Wah, Manisha, Joel, Li Teng, and Jessie for their helpful suggestions and assistance. Special thanks to Dr. Tang Man Li for her guidance at the beginning of my study and Tang Xiao Yan and Ong Li Teng for the support they gave me when I encounter problems in my studies. Finally, I am indebted to my parents, husband, and friends. They provided me selfless help and encouragement during the course of my Ph.D.
    [Show full text]
  • Structural Mechanism of Laminin Recognition by Integrin
    ARTICLE https://doi.org/10.1038/s41467-021-24184-8 OPEN Structural mechanism of laminin recognition by integrin Takao Arimori 1, Naoyuki Miyazaki 1,2, Emiko Mihara 1, Mamoru Takizawa3, Yukimasa Taniguchi3, ✉ Carlos Cabañas 4,5,6, Kiyotoshi Sekiguchi3 & Junichi Takagi 1 Recognition of laminin by integrin receptors is central to the epithelial cell adhesion to basement membrane, but the structural background of this molecular interaction remained 1234567890():,; elusive. Here, we report the structures of the prototypic laminin receptor α6β1 integrin alone and in complex with three-chain laminin-511 fragment determined via crystallography and cryo-electron microscopy, respectively. The laminin-integrin interface is made up of several binding sites located on all five subunits, with the laminin γ1 chain C-terminal portion pro- viding focal interaction using two carboxylate anchor points to bridge metal-ion dependent adhesion site of integrin β1 subunit and Asn189 of integrin α6 subunit. Laminin α5 chain also contributes to the affinity and specificity by making electrostatic interactions with large surface on the β-propeller domain of α6, part of which comprises an alternatively spliced X1 region. The propeller sheet corresponding to this region shows unusually high mobility, suggesting its unique role in ligand capture. 1 Laboratory for Protein Synthesis and Expression, Institute for Protein Research, Osaka University, Suita, Osaka, Japan. 2 Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Ibaraki, Japan. 3 Division of Matrixome Research and Application, Institute for Protein Research, Osaka University, Suita, Osaka, Japan. 4 Cell-cell Communication & Inflammation Unit, Centro de Biología Molecular Severo Ochoa (CSIC- UAM), Madrid, Spain.
    [Show full text]
  • The Integrin Equilibrium: Balancing Protein-Protein and Protein-Lipid Interactions" (2012)
    University of Pennsylvania ScholarlyCommons Publicly Accessible Penn Dissertations 2012 The Integrin Equilibrium: Balancing Protein-Protein and Protein- Lipid interactions David Thomas Moore University of Pennsylvania, [email protected] Follow this and additional works at: https://repository.upenn.edu/edissertations Part of the Biochemistry Commons, and the Biophysics Commons Recommended Citation Moore, David Thomas, "The Integrin Equilibrium: Balancing Protein-Protein and Protein-Lipid interactions" (2012). Publicly Accessible Penn Dissertations. 553. https://repository.upenn.edu/edissertations/553 This paper is posted at ScholarlyCommons. https://repository.upenn.edu/edissertations/553 For more information, please contact [email protected]. The Integrin Equilibrium: Balancing Protein-Protein and Protein-Lipid interactions Abstract On circulating platelets, the integrin fibrinogen eceptr or &alphaIIb&beta3 favors inactive conformations. Platelets rapidly activate &alphaIIb&beta3 to bind fibrinogen, mediating a platelet clot. Resting &alphaIIb&beta3 is stabilized by interactions between the &alphaIIb and &beta3 transmembrane domains. Binding of talin-1 and kindlin-3 to the integrin cytoplasmic domain stabilizes separation of the TMs and receptor activation. Src family kinases are needed for transmission of extracellular signals into the cell. We have sought to better understand how signals are transmitted across the &alphaIIb&beta3 TM domain. First we characterized the structure and dynamics of the active and inactive integrin cytoplasmic domain to determine how motifs that bind talin-1 and kindlin-3 are affected by the integrin activation state and the membrane environment. The &alphaIIb&beta3 cytoplasmic domain is disorded, while the &beta3 subunit contains two &alpha-helices, which interact with the phospholipid bilayer. The close proximity of &alphaIIb to &beta3 in the inactive state induces a kink that projects the &beta-chain parallel to the membrane surface.
    [Show full text]
  • Structural Basis of Blocking Integrin Activation and Deactivation for Anti-Inflammation Eun Jeong Park1,2*, Yoshikazu Yuki2, Hiroshi Kiyono2,3 and Motomu Shimaoka1
    Park et al. Journal of Biomedical Science (2015) 22:51 DOI 10.1186/s12929-015-0159-6 REVIEW Open Access Structural basis of blocking integrin activation and deactivation for anti-inflammation Eun Jeong Park1,2*, Yoshikazu Yuki2, Hiroshi Kiyono2,3 and Motomu Shimaoka1 Abstract Integrins mediate leukocyte accumulation to the sites of inflammation, thereby enhancing their potential as an important therapeutic target for inflammatory disorders. Integrin activation triggered by inflammatory mediators or signaling pathway is a key step to initiate leukocyte migration to inflamed tissues; however, an appropriately regulated integrin deactivation is indispensable for maintaining productive leukocyte migration. While typical integrin antagonists that block integrin activation target the initiation of leukocyte migration, a novel class of experimental compounds has been designed to block integrin deactivation, thereby perturbing the progression of cell migration. Current review discusses the mechanisms by which integrin is activated and subsequently deactivated by focusing on its structure-function relationship. Keywords: Integrin, Affinity, Activation, Deactivation, Leukocyte, Inflammation, Talin, Kindlin Introduction Integrins play a critical role in the regulation of extrava- Integrins are the largest family of cell adhesion molecules sation of leukocytes to sites of inflammation [5, 11, 12]. that mediate cell-to-cell and cell-to-matrix interactions in During rolling along the endothelial cells via selectins, leu- abroadrangeofbiologicalphenomenonsuchashost kocytes encounter chemokines expressed on endothelial defense, hemostasis, wound healing, angiogenesis, organ cells [87]. The integrin activation by chemokine enables development [3, 29, 43, 63, 73]. These functions are abrupt arrest of cells on endothelial integrin ligands. achieved via integrin bidirectional signaling across plasma Subsequently adherent leukocytes leave the initial point membrane [34, 55].
    [Show full text]
  • Exposure Arthritis Through Differential Epitope Inflammation Distinguishes Three Types of Leukocyte Membranes During Synovial CD
    The Journal of Immunology Shedding of Large Functionally Active CD11/CD18 Integrin Complexes from Leukocyte Membranes during Synovial Inflammation Distinguishes Three Types of Arthritis through Differential Epitope Exposure Louise Carstensen Gjelstrup,*,†,‡ Thomas Boesen,x Tue Wenzel Kragstrup,†,{ Annette Jørgensen,{ Nigel J. Klein,‖ Steffen Thiel,† Bent Winding Deleuran,†,{ and Thomas Vorup-Jensen*,†,‡ CD18 integrins are adhesion molecules expressed on the cell surface of leukocytes and play a central role in the molecular mech- anisms supporting leukocyte migration to zones of inflammation. Recently, it was discovered that CD11a/CD18 is shed from the leukocyte surface in models of inflammation. In this study, we show that shedding of human CD11/CD18 complexes is a part of synovial inflammation in rheumatoid arthritis and spondyloarthritis but not in osteoarthritis. In vivo and in vitro data suggest that the shedding is driven by TNF-a, which links the process to central events in the inflammatory response. The shed complexes contain multiple heterodimers of CD11/CD18, are variable in size, and differ according to the type of synovial inflammation. Furthermore, the differential structures determine the avidity of binding of the complexes to the ICAM-1. With the estimated concentrations of CD11/CD18 in plasma and synovial fluid a significant coverage of binding sites in ICAM-1 for CD18 integrins is expected. Based on cell adhesion experiments in vitro, we hypothesize that the large soluble complexes of CD11/CD18 act in vivo to buffer leukocyte adhesion by competing with the membrane-bound receptors for ICAM-1 binding sites. As reported here for synovial inflammation changes in the concentration or structure of these complexes should be considered as likely contributors to disease activity.
    [Show full text]
  • WO 2016/087245 Al 9 June 2016 (09.06.2016) P O P C T
    (12) INTERNATIONAL APPLICATION PUBLISHED UNDER THE PATENT COOPERATION TREATY (PCT) (19) World Intellectual Property Organization International Bureau (10) International Publication Number (43) International Publication Date WO 2016/087245 Al 9 June 2016 (09.06.2016) P O P C T (51) International Patent Classification: (81) Designated States (unless otherwise indicated, for every C07K 16/24 (2006.01) A61K 39/395 (2006.01) kind of national protection available): AE, AG, AL, AM, AO, AT, AU, AZ, BA, BB, BG, BH, BN, BR, BW, BY, (21) International Application Number: BZ, CA, CH, CL, CN, CO, CR, CU, CZ, DE, DK, DM, PCT/EP2015/07733 1 DO, DZ, EC, EE, EG, ES, FI, GB, GD, GE, GH, GM, GT, (22) International Filing Date: HN, HR, HU, ID, IL, IN, IR, IS, JP, KE, KG, KN, KP, KR, 23 November 2015 (23.1 1.2015) KZ, LA, LC, LK, LR, LS, LU, LY, MA, MD, ME, MG, MK, MN, MW, MX, MY, MZ, NA, NG, NI, NO, NZ, OM, (25) Filing Language: English PA, PE, PG, PH, PL, PT, QA, RO, RS, RU, RW, SA, SC, (26) Publication Language: English SD, SE, SG, SK, SL, SM, ST, SV, SY, TH, TJ, TM, TN, TR, TT, TZ, UA, UG, US, UZ, VC, VN, ZA, ZM, ZW. (30) Priority Data: 14195645.8 1 December 2014 (01. 12.2014) (84) Designated States (unless otherwise indicated, for every kind of regional protection available): ARIPO (BW, GH, (71) Applicants: DEUTSCHES KREBSFORSCHUNG- GM, KE, LR, LS, MW, MZ, NA, RW, SD, SL, ST, SZ, SZENTRUM [DE/DE]; Stiftung des oeffentlichen Rechts, TZ, UG, ZM, ZW), Eurasian (AM, AZ, BY, KG, KZ, RU, Im Neuenheimer Feld 280, 69120 Heidelberg (DE).
    [Show full text]
  • Structure of the Integrin Receptor Αmβ2 Headpiece in Complex with a Function-Modulating Nanobody
    bioRxiv preprint doi: https://doi.org/10.1101/2021.07.07.451531; this version posted July 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Structure of the αMβ2 headpiece in the closed conformation Structure of the integrin receptor αMβ2 headpiece in complex with a function- modulating nanobody Rasmus K. Jensen1, Henrik Pedersen1, Josefine Lorentzen1, Nick Stub Laursen2, Thomas Vorup-Jensen2, Gregers Rom Andersen1* 1 Department of Molecular Biology and Genetics, Aarhus University, Denmark 2 Department of Biomedicine, Aarhus University, Denmark *To whom correspondence should be addressed. Gregers Rom Andersen, Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10C DK8000 Aarhus, Denmark. [email protected] ; Tel +4530256646 1 bioRxiv preprint doi: https://doi.org/10.1101/2021.07.07.451531; this version posted July 8, 2021. The copyright holder for this preprint (which was not certified by peer review) is the author/funder. All rights reserved. No reuse allowed without permission. Structure of the αMβ2 headpiece in the closed conformation Abstract The integrin receptor αMβ2 mediates phagocytosis of complement-opsonized objects, adhesion to the extracellular matrix and trans-endothelial migration of leukocytes. Here we present the first atomic structure of the human αMβ2 headpiece fragment in complex with the nanobody hCD11bNb1 determined at a resolution of 3.2 Å. The receptor headpiece adopts the closed conformation expected to have low ligand affinity. The crystal structure advocates that in the R77H αM variant associated with systemic lupus erythematosus, the modified allosteric coupling between ligand coupling and integrin outside-inside signalling is due to subtle conformational effects transmitted over 40 Å.
    [Show full text]
  • The Activation and Regulation of Β2 Integrins in Phagocytes And
    MINI REVIEW published: 31 March 2021 doi: 10.3389/fimmu.2021.633639 The Activation and Regulation of b2 Integrins in Phagocytes and Phagocytosis † † Hao Sun 1 , Kangkang Zhi 2 , Liang Hu 3 and Zhichao Fan 4* 1 Department of Medicine, University of California, San Diego, La Jolla, CA, United States, 2 Department of Vascular Surgery, Changzheng Hospital, Shanghai, China, 3 Department of Cardiology, Cardiovascular Institute of Zhengzhou University, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China, 4 Department of Immunology, School of Medicine, UConn Health, Farmington, CT, United States Phagocytes, which include neutrophils, monocytes, macrophages, and dendritic cells, protect the body by removing foreign particles, bacteria, and dead or dying cells. Phagocytic integrins are greatly involved in the recognition of and adhesion to specific antigens on cells and pathogens during phagocytosis as well as the recruitment of Edited by: immune cells. b2 integrins, including aLb2, aMb2, aXb2, and aDb2, are the major Valentin Jaumouille´ , integrins presented on the phagocyte surface. The activation of b2 integrins is essential to Simon Fraser University, Canada the recruitment and phagocytic function of these phagocytes and is critical for the Reviewed by: fl Esther M. Lafuente, regulation of in ammation and immune defense. However, aberrant activation of b2 Complutense University of Madrid, integrins aggravates auto-immune diseases, such as psoriasis, arthritis, and multiple Spain sclerosis, and facilitates tumor metastasis, making them double-edged swords as Pontus Nordenfelt, Lund University, Sweden candidates for therapeutic intervention. Therefore, precise regulation of phagocyte Mehmet Sen, activities by targeting b2 integrins should promote their host defense functions with University of Houston, United States minimal side effects on other cells.
    [Show full text]
  • ― D12 - 1 ― 医学中央雑誌刊行会・医学用語シソーラス 第9版（ 2019） カテゴリー別リスト
    医学中央雑誌刊行会・医学用語シソーラス 第9版（ 2019） カテゴリー別リスト Amino Acids, Peptides, and Proteins D12+ Amino Acids D12-10+ Acidic Amino Acids D12-10-10+ Aspartic Acid D12-10-10-10+ # D-Aspartic Acid D12-10-10-10-10 # * Calcium Aspartate D12-10-10-10-20 # Isoaspartic Acid D12-10-10-10-30 # N-Methylaspartate D12-10-10-10-40 # * Potassium Aspartate D12-10-10-10-50 # Potassium Magnesium Aspartate D12-10-10-10-60 # Sparfosic Acid D12-10-10-10-70 # Glutamates D12-10-10-20+ # 1-Carboxyglutamic Acid D12-10-10-20-10 # * Carglumic Acid D12-10-10-20-20 # Glutamic Acid D12-10-10-20-30+ # Sodium Glutamate D12-10-10-20-30-10 # Pemetrexed D12-10-10-20-40 # Polyglutamic Acid D12-10-10-20-50+ # Paclitaxel Poliglumex D12-10-10-20-50-10 # Pyrrolidonecarboxylic Acid D12-10-10-20-60 # Alanine D12-10-20+ Alafosfalin D12-10-20-10 # Alanosine D12-10-20-20 # Alaproclate D12-10-20-30 # Beta-Alanine D12-10-20-40+ Pantothenic Acid D12-10-20-40-10+ # Hopantenic Acid D12-10-20-40-10-10 # Panthenol D12-10-20-40-10-20 # Betamipron D12-10-20-50 Brivanib Alaninate D12-10-20-60 # Lysinoalanine D12-10-20-70 # Managlinat Dialanetil D12-10-20-80 # Mimosine D12-10-20-90 # Orbofiban D12-10-20-100 # Rebamipide D12-10-20-110 # Safinamide D12-10-20-120 # Semagacestat D12-10-20-130 # Amino Acid Chloromethyl Ketones D12-10-30+ # Tosyllysine Chloromethyl Ketone D12-10-30-10 # Tosylphenylalanyl Chloromethyl Ketone D12-10-30-20 # Amino Acyl tRNA D12-10-40 # Aminobutyrates D12-10-50+ # Aminoisobutyric Acids D12-10-50-10 # Gamma-Aminobutyric Acid D12-10-50-20+ # Carpronium Chloride D12-10-50-20-10 # Gabapentin
    [Show full text]
  • Enhancing Haematopoeitic Stem Cell Recruitment to Injured Murine Colon
    Enhancing Haematopoeitic Stem Cell Recruitment to Injured Murine Colon By Adrian Ian Yemm A thesis submitted to The University of Birmingham for the degree of Doctor of Philosophy College of Medical and Dental Sciences School of Clinical and Experimental Medicine University of Birmingham September 2013 University of Birmingham Research Archive e-theses repository This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder. Abstract Haematopoietic stem cells (HSCs) have been described as potential therapeutic agents for the repair of several inflammatory injuries including inflammatory bowel diseases (IBDs). However, their efficacy within clinics has been poor. This has been partially attributed to poor recruitment to sites of injury. Thus identifying the mechanisms by which HSCs are recruited to inflamed bowel, and developing strategies to enhance this recruitment, may increase their clinical efficacy. Critical adhesive mechanisms and several pre-treatment strategies to enhance adhesion to chronically (DSS induced colitis) and acutely (IR) injured murine colon were investigated in vitro and in vivo. It was found that recruitment to IR injured colon was mediated by CD49d, whereas recruitment to colitic colon was mediated by both CD18 and CD49d. In vitro investigation revealed that both hydrogen peroxide (H2O2) and platelet derived pre-treatments, such as coating HSCs with platelet microparticles (PMPs), could enhance adhesion to colon endothelial cells, immobilised endothelial counterligands ICAM-1 and VCAM-1 and frozen tissue sections.
    [Show full text]
  • Monoclonal Antibody to Cd11c Percp (100 Tests)
    PC-529-T100 Monoclonal Antibody to CD11c PerCP (100 tests) Clone: BU15 Isotype: Mouse IgG1 Specificity: The antibody BU15 reacts with CD11c (alphaX, p150), a 150 kDa integrin expressed mainly on dendritic cells and tissue macrophages. HLDA III; WS Code M 256 HLDA V; WS Code AS S143 HLDA VI; WS Code AS Ref.6 Regulatory Status: RUO Immunogen: Dendritic cells of synovial fluid Species Reactivity: Human, Monkey Preparation: The purified antibody is conjugated with Peridinin-chlorophyll-protein complex (PerCP) under optimum conditions. The conjugate is purified by size-exclusion chromatography and adjusted for direct use. No reconstitution is necessary. Storage Buffer: The reagent is provided in stabilizing phosphate buffered saline (PBS) solution containing 15mM sodium azide. Storage / Stability: Store in the dark at 2-8oC. Do not freeze. Avoid prolonged exposure to light. Do not use after expiration date stamped on vial label. Usage: The reagent is designed for Flow Cytometry analysis of human blood cells using 10 µl reagent / 100 µl of whole blood or 106 cells in a suspension. The content of a vial (1 ml) is sufficient for 100 tests. Expiration: See vial label Lot Number: See vial label Background: CD11c (p150, alphaX integrin subunit) forms complex with CD18 (beta2 integrin subunit) and is expressed mainly on tissue macrophages and dendritic cells. CD11c binds to complement fragment iC3b, fibrinogen, VCAM-1 and ICAM-2 or e.g. CD90. Like other beta2 integrins, CD11c/CD18 plays roles in cell migration and phagocytosis. Moreover, interaction of CD11c/CD18 with plasminogen regulates plasmin activities, and interaction with heparin counteracts binding of iC3b.
    [Show full text]
  • Molecular Basis for Complement Recognition by Integrin Αxβ2 Xing Chena,1, Yamei Yua, Li-Zhi Mia, Thomas Walzb, and Timothy A
    Molecular basis for complement recognition by integrin αXβ2 Xing Chena,1, Yamei Yua, Li-Zhi Mia, Thomas Walzb, and Timothy A. Springera,2 aImmune Disease Institute, Children’s Hospital Boston, and Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115; and bHoward Hughes Medical Institute and Department of Cell Biology, Harvard Medical School, Boston, MA 02115 Contributed by Timothy A. Springer, February 6, 2012 (sent for review November 9, 2011) Integrin αXβ2 functions as complement receptor for iC3b and medi- identified and perhaps the most specifically recognized of these ates recognition and phagocytosis of pathogens. We used nega- ligands. Surface plasmon resonance studies have shown higher α β tive-stain EM to examine the X 2 interaction with iC3b. EM class affinity of a mutant, high-affinity αX I domain for iC3b than for averages of αXβ2 in complex with iC3b define the binding sites on other ligands, such as fibrinogen (17, 18). However, the molec- both the integrin and iC3b. iC3b contains C3c and thioester domain ular basis for selectivity of αXβ2 for iC3b in rosetting assays and moieties linked by a long flexible linker. The binding site is on the the binding site within iC3b have not been defined. Initially, the key ring of the C3c moiety, at the interface between the MG3 and closely related integrin αMβ2 (CR3) was reported to bind to an MG4 domains. Similar complexes are seen between αXβ2 and the C3c Arg-Gly-Asp (RGD) sequence within iC3b based on inhibition fragment. αXβ2 binds through the αX αI domain, on the face known with peptides (19).
    [Show full text]