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Tal MC, Hansen PS, Ogasawara HA, Feng Q, Volk RF, Lee B, Casebeer SE, Blacker GS, Shoham M, Galloway SD, Sapiro AL, Hayes B, Dulgeroff LBT, Raveh T, Pothineni VR, Potula HHS, Rajadas J, Bastounis EE, Chou S, Robinson WH, Coburn J, Weissman IL, Zaro BW. P66 is a bacterial mimic of CD47 that binds the anti-phagocytic receptor SIRPα and facilitates macrophage evasion by Borrelia burgdorferi. bioRxiv 2024:2024.04.29.591704. [PMID: 38746193 PMCID: PMC11092639 DOI: 10.1101/2024.04.29.591704] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Innate immunity, the first line of defense against pathogens, relies on efficient elimination of invading agents by phagocytes. In the co-evolution of host and pathogen, pathogens developed mechanisms to dampen and evade phagocytic clearance. Here, we report that bacterial pathogens can evade clearance by macrophages through mimicry at the mammalian anti-phagocytic "don't eat me" signaling axis between CD47 (ligand) and SIRPα (receptor). We identified a protein, P66, on the surface of Borrelia burgdorferi that, like CD47, is necessary and sufficient to bind the macrophage receptor SIRPα. Expression of the gene encoding the protein is required for bacteria to bind SIRPα or a high-affinity CD47 reagent. Genetic deletion of p66 increases phagocytosis by macrophages. Blockade of P66 during infection promotes clearance of the bacteria. This study demonstrates that mimicry of the mammalian anti-phagocytic protein CD47 by B. burgdorferi inhibits macrophage-mediated bacterial clearance. Such a mechanism has broad implications for understanding of host-pathogen interactions and expands the function of the established innate immune checkpoint receptor SIRPα. Moreover, this report reveals P66 as a novel therapeutic target in the treatment of Lyme Disease.
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Shoham M, Yiu YY, Hansen PS, Subramaniam A, Broberg M, Gars E, Raveh T, FinnGen, Weissman IL, Sinnott-Armstrong N, Krishnan A, Ollila HM, Tal MC. SIRPα controls CD47-dependent platelet clearance in mice and humans. bioRxiv 2023:2023.12.09.570874. [PMID: 38106070 PMCID: PMC10723388 DOI: 10.1101/2023.12.09.570874] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Over the last decade, more data has revealed that increased surface expression of the "don't eat me" CD47 protein on cancer cells plays a role in immune evasion and tumor progression, with CD47 blockade emerging as a new therapy in immuno-oncology. CD47 is critical in regulating cell homeostasis and clearance, as binding of CD47 to the inhibitory receptor SIRPα can prevent phagocytosis and macrophage-mediated cell clearance. The purpose of this study was to examine the role of the CD47-SIRPα signal in platelet homeostasis and clearance. Therapeutic reagents targeting the CD47-SIRPα axis are very promising for treatment of hematologic malignancies and solid tumors, but lead to transient anemia or thrombocytopenia in a subset of patients. We found that platelet homeostatic clearance is regulated through the CD47-SIRPα axis and that therapeutic blockade to disrupt this interaction in mice and in humans has a significant impact on platelet levels. Furthermore, we identified genetic variations at the SIRPA locus that impact platelet levels in humans such that higher SIRPA gene expression is associated with higher platelet levels. SIRPA expression at either end of the normal range may affect clinical outcomes of treatment with anti-CD47 therapy.
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Affiliation(s)
- Maia Shoham
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Ludwig Cancer Center, Stanford University School of Medicine, Stanford, CA, USA
| | - Ying Ying Yiu
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Ludwig Cancer Center, Stanford University School of Medicine, Stanford, CA, USA
| | - Paige S. Hansen
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Aanya Subramaniam
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Martin Broberg
- Institute for Molecular Medicine, FIMM, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Eric Gars
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
| | - Tal Raveh
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
| | | | - Irving L. Weissman
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Ludwig Cancer Center, Stanford University School of Medicine, Stanford, CA, USA
| | - Nasa Sinnott-Armstrong
- Department of Genetics, Stanford University, Stanford, CA, USA
- Metabolism Program and Cardiovascular Disease Initiative, Broad Institute of Massachusetts Institute of Technology and Harvard University, Cambridge, MA, USA
| | - Anandi Krishnan
- Department of Pathology, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Cancer Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Hanna M. Ollila
- Institute for Molecular Medicine, FIMM, HiLIFE, University of Helsinki, Helsinki, Finland
- Center for Genomic Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Broad Institute for Harvard and MIT, Boston, MA, USA
- Anesthesia, Critical Care, and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Michal Caspi Tal
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA, USA
- Department of Biological Engineering, Massachusetts Institute of Technology, Cambridge, MA, USA
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Shoham M, Pang JH, Satterwhite T. Considerations for secondary vaginoplasty. Transl Androl Urol 2022; 11:1480-1483. [PMID: 36507476 PMCID: PMC9732695 DOI: 10.21037/tau-22-660] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2022] [Accepted: 11/03/2022] [Indexed: 11/24/2022] Open
Affiliation(s)
- Maia Shoham
- Stanford University School of Medicine, Stanford, CA, USA
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Lee B, Galloway S, Strausz S, Shoham M, Hansen P, Mansfield P, Salomon R, Torrez-Dulgeroff LB, Saleem A, Gars E, Sanders E, Ollila H, Weissman IL, Tal MC. Novel Association of Lyme disease, Age, and Atopic Dermatitis. The Journal of Immunology 2022. [DOI: 10.4049/jimmunol.208.supp.49.26] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
Borrelia burgdorferi is a bacterial spirochete that can cause Lyme disease (LD) after infecting a susceptible host. Immune responses to the bacteria are highly variable and host specific. The murine substrain, C3H/HeJ, is a frequently utilized model for LD. Interestingly, over a prolonged infection, mice develop dermatitis on tail skin, which shares critical features with human skin. Female C3H/HeJ mice aged 5–8 weeks, 1 year, or 2 years were infected intraperitoneally with 105 B. burgdorferi. Dermatitis was evaluated by gross examination and histology. Dermatitis worsened over the course of untreated infection, with ulceration, hemorrhaging, flaking, hair loss, and dark lesions as well as spongiosis and acanthosis. These features of dermatitis were present in infected mice after 1 year of age. This relationship among LD, atopic dermatitis, and host age seen in the C3H/HeJ mouse model is consistent with a large pool (342,499) of human epidemiological data from Finland. We identified 5,248 individuals with LD and 17,233 with atopic dermatitis in FinnGen. Retrospective analysis shows LD is associated with atopic dermatitis (OR = 1.91 [1.68 −2.37], P < 2e−16). More visits due to LD complications (3 or more visits versus 1 visit) were associated with atopic dermatitis (OR = 2.19 [1.35–3.55], P = 0.0014) and risk of developing atopic dermatitis over time (HR = 2.26 [1.54–3.95], P = 0.0017). Data from mice and humans reveal a novel relationship among LD, age, and atopic dermatitis. Through defined pathological scoring, we demonstrate the onset of murine atopic dermatitis with B. burgdorferi infection, which is further exacerbated by host age at time of infection, and likewise report a similar association in human epidemiological data from FinnGen.
Research was supported by the Fairbairn Family foundation; Bay Area Lyme Foundation; the Younger family foundation; the Robert J. Kleberg, Jr., and Helen C. Kleberg Foundation; the Virginia and D. K. Ludwig Fund for Cancer Research; AML grant R01CA086017; the PCBC from NIHLB U01HL099999; as well as grant U19AI109662. M.C.T. was supported by Stanford Immunology training grant 5T32AI007290, and the NIH NRSA 1 F32 AI124558-01 award. L.B.T.D. was supported by a Stanford Diversifying Academia Recruiting Excellence fellowship. S.G. was supported by the California Institute for Regenerative Medicine. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
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Affiliation(s)
- Brandon Lee
- 1Biological Engineering, Massachusetts Institute of Technology
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | - Sarah Galloway
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | - Satu Strausz
- 3Institute for Molecular Medicine Finland, Helsinki University, Finland
| | - Maia Shoham
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | - Paige Hansen
- 1Biological Engineering, Massachusetts Institute of Technology
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | - Paul Mansfield
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | - Rachel Salomon
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | | | - Atif Saleem
- 4Pathology, Stanford University School of Medicine
| | - Eric Gars
- 4Pathology, Stanford University School of Medicine
| | - Erin Sanders
- 1Biological Engineering, Massachusetts Institute of Technology
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | - Hanna Ollila
- 3Institute for Molecular Medicine Finland, Helsinki University, Finland
- 5Program in Medical and Population Genetics, Broad Inst. of MIT and Harvard
- 6Genetics, Stanford Univ
| | - Irving L Weissman
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
| | - Michal Caspi Tal
- 1Biological Engineering, Massachusetts Institute of Technology
- 2Institute for Stem Cell Biology & Regenerative Medicine, Stanford University School of Medicine
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Galloway SD, Shoham M, Lee B, Torrez-Dulgeroff LB, Irnov I, Lin A, Strausz S, Hansen P, Blacker G, Salomon-Shulman R, Potula HHSK, Markovic M, Nahass GR, Colace O, Raveh T, Pollack B, Sanders E, Ollila H, Wagner CJ, Robinson WH, Weissman IL, Tal MC. Characterization of pathological IgE-mediated mast cell activation in Lyme disease. The Journal of Immunology 2022. [DOI: 10.4049/jimmunol.208.supp.161.12] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Abstract
Lyme disease, caused by the bacteria Borrelia burgdorferi, is the most common and rapidly growing vector-borne infectious disease in the United States and Europe. High variability in disease burden among Lyme patients suggests that individual immune responses may be key drivers of clinical presentation and patient outcomes. Use of high resolution flow-based immunosorbent profiling revealed that a subset of Lyme patients with persistent symptoms were producing high concentrations of IgE specific to B. burgdorferi. Comparing C57B/6 mice, which are tolerant to B. burgdorferi, and C3H/HeJ mice, which are susceptible to disease, we find high levels of IgE specific for B. burgdorferi in C3H/HeJ but not C57B/6 mice. Furthermore, IgE was found to target Borrelia peptidoglycan in both acute and chronic infection models. Histologic analysis of mouse Lyme arthritic ankle tissue showed mast cells, which release highly immunogenic effectors upon activation by bound IgE, degranulating at significantly higher rates compared to uninfected controls. Forced mast cell degranulation exacerbated Lyme arthritis in infected mice. This data suggests that a subset of Lyme patients with persistent symptoms may have developed an allergic response to conserved bacterial antigens from a B. burgdorferi infection, as opposed to an autoimmune type response. Inclusion of IgE reactivity in diagnostic testing and examination of pathological immune responses to bacterial antigens could assist clinicians in patient care and effective treatments.
Research reported in this publication was supported by the Fairbairn family foundation; Bay Area Lyme Foundation; the Younger family foundation; the Robert J. Kleberg, Jr., and Helen C. Kleberg Foundation; the Virginia and D. K. Ludwig Fund for Cancer Research; M.C.T. was supported by Stanford Immunology training grant 5T32AI007290, and the NIH NRSA 1 F32 AI124558-01 award. L.B.T.D. was supported by a Stanford Diversifying Academia Recruiting Excellence fellowship. S.D.G was supported by the California Institute for Regenerative Medicine Bridges 2.0 Training Program grant EDUC2-08397. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
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Affiliation(s)
- Sarah D Galloway
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | - Maia Shoham
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | | | | | - Irnov Irnov
- 3Department of Biology and ChEM-H Institute, Stanford University
| | - Athena Lin
- 3Department of Biology and ChEM-H Institute, Stanford University
| | | | | | - Grace Blacker
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | - Rachel Salomon-Shulman
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | | | - Maxim Markovic
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | - George R Nahass
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | - Olivia Colace
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | - Tal Raveh
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | | | | | | | | | - William H Robinson
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
| | - Irving L Weissman
- 1Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine
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Shoham M, Baker N, Peterson M, Fox P. The Environmental Impact of Surgery. J Am Coll Surg 2021. [DOI: 10.1016/j.jamcollsurg.2021.07.258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Tsai JM, Sinha R, Seita J, Fernhoff N, Christ S, Koopmans T, Krampitz GW, McKenna KM, Xing L, Sandholzer M, Sales JH, Shoham M, McCracken M, Joubert LM, Gordon SR, Poux N, Wernig G, Norton JA, Weissman IL, Rinkevich Y. Surgical adhesions in mice are derived from mesothelial cells and can be targeted by antibodies against mesothelial markers. Sci Transl Med 2018; 10:eaan6735. [PMID: 30487249 DOI: 10.1126/scitranslmed.aan6735] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2017] [Revised: 09/26/2017] [Accepted: 04/30/2018] [Indexed: 11/20/2023]
Abstract
Peritoneal adhesions are fibrous tissues that tether organs to one another or to the peritoneal wall and are a major cause of postsurgical and infectious morbidity. The primary molecular chain of events leading to the initiation of adhesions has been elusive, chiefly due to the lack of an identifiable cell of origin. Using clonal analysis and lineage tracing, we have identified injured surface mesothelium expressing podoplanin (PDPN) and mesothelin (MSLN) as a primary instigator of peritoneal adhesions after surgery in mice. We demonstrate that an anti-MSLN antibody diminished adhesion formation in a mouse model where adhesions were induced by surgical ligation to form ischemic buttons and subsequent surgical abrasion of the peritoneum. RNA sequencing and bioinformatics analyses of mouse mesothelial cells from injured mesothelium revealed aspects of the pathological mechanism of adhesion development and yielded several potential regulators of this process. Specifically, we show that PDPN+MSLN+ mesothelium responded to hypoxia by early up-regulation of hypoxia-inducible factor 1 alpha (HIF1α) that preceded adhesion development. Inhibition of HIF1α with small molecules ameliorated the injury program in damaged mesothelium and was sufficient to diminish adhesion severity in a mouse model. Analyses of human adhesion tissue suggested that similar surface markers and signaling pathways may contribute to surgical adhesions in human patients.
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Affiliation(s)
- Jonathan M Tsai
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Rahul Sinha
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jun Seita
- AI based Healthcare and Medical Data Analysis Standardization Unit, Medical Sciences Innovation Hub Program, RIKEN, Tokyo 103-0027, Japan
| | - Nathaniel Fernhoff
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Simon Christ
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Tim Koopmans
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Geoffrey W Krampitz
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of General Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Kelly M McKenna
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Liujing Xing
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Michael Sandholzer
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Jennifer Horatia Sales
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
| | - Maia Shoham
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Melissa McCracken
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Lydia-Marie Joubert
- Cell Sciences Imaging Facility, Beckman Center, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Sydney R Gordon
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Nicolas Poux
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Gerlinde Wernig
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Jeffrey A Norton
- Department of General Surgery, Stanford University School of Medicine, Stanford, CA 94305, USA
| | - Irving L Weissman
- Institute for Stem Cell Biology and Regenerative Medicine, Stanford University School of Medicine, Stanford, CA 94305, USA.
- Department of Developmental Biology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Department of Pathology, Stanford University School of Medicine, Stanford, CA 94305, USA
- Ludwig Center for Cancer Stem Cell Biology and Medicine at Stanford University, Stanford, CA 94305, USA
| | - Yuval Rinkevich
- Comprehensive Pneumology Center, Institute of Lung Biology and Disease,Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany.
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Abstract
The paper reports studies on the motion planning problem for planar star-shaped manipulators. These manipulators are formed by joining k “legs” to a common point (like the thorax of an insect) and then fixing the “feet” to the ground. The result is a planar parallel manipulator with k - 1 independent closed loops. A topological analysis is used to understand the global structure of the configuration space so that the planning problem can be solved exactly. The worst-case complexity of the algorithm is O(k3 N 3 ), where N is the maximum number of links in a leg. Examples illustrating the method are given.
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Affiliation(s)
- N. Shvalb
- Department of ME, Technion-Israel Institute of Technology, Israel,
| | - M. Shoham
- Department of ME, Technion-Israel Institute of Technology, Israel
| | - G. Liu
- Department of Computer Science, Stanford University, Stanford, CA, USA,
| | - J.C. Trinkle
- Department of Computer Science, Rensselaer Polytechnic Institute, USA,
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Zarrouk D, Sharf I, Shoham M. Conditions for Worm-Robot Locomotion in a Flexible Environment: Theory and Experiments. IEEE Trans Biomed Eng 2012; 59:1057-67. [DOI: 10.1109/tbme.2011.2182612] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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Shoham M, Lieberman IH, Benzel EC, Togawa D, Zehavi E, Zilberstein B, Roffman M, Bruskin A, Fridlander A, Joskowicz L, Brink-Danan S, Knoller N. Robotic assisted spinal surgery–from concept to clinical practice. ACTA ACUST UNITED AC 2010; 12:105-15. [PMID: 17487660 DOI: 10.3109/10929080701243981] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
After several years of product development, animal trials and human cadaver testing, the SpineAssist--a miniature bone-mounted robotic system--has recently entered clinical use. To the best of the authors' knowledge, this is the only available image-based mechanical guidance system that enables pedicle screw insertion with an overall accuracy in the range of 1 mm in both open and minimally invasive procedures. In this paper, we describe the development and clinical trial process that has brought the SpineAssist to its current state, with an emphasis on the various difficulties encountered along the way and the corresponding solutions. All aspects of product development are discussed, including mechanical design, CT-to-fluoroscopy image registration, and surgical techniques. Finally, we describe a series of preclinical trials with human cadavers, as well as clinical use, which verify the system's accuracy and efficacy.
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Affiliation(s)
- M Shoham
- Department of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa, Israel.
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12
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Joskowicz L, Shamir R, Freiman M, Shoham M, Zehavi E, Umansky F, Shoshan Y. Image-guided system with miniature robot for precise positioning and targeting in keyhole neurosurgery. ACTA ACUST UNITED AC 2010; 11:181-93. [PMID: 17038306 DOI: 10.3109/10929080600909351] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
This paper describes a novel image-guided system for precise automatic targeting in minimally invasive keyhole neurosurgery. The system consists of the MARS miniature robot fitted with a mechanical guide for needle, probe or catheter insertion. Intraoperatively, the robot is directly affixed to a head clamp or to the patient's skull. It automatically positions itself with respect to predefined targets in a preoperative CT/MRI image following an anatomical registration with an intraoperative 3D surface scan of the patient's facial features and registration jig. We present the system architecture, surgical protocol, custom hardware (targeting and registration jig), and software modules (preoperative planning, intraoperative execution, 3D surface scan processing, and three-way registration). We also describe a prototype implementation of the system and in vitro registration experiments. Our results indicate a system-wide target registration error of 1.7 mm (standard deviation = 0.7 mm), which is close to the required 1.0-1.5 mm clinical accuracy in many keyhole neurosurgical procedures.
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Affiliation(s)
- L Joskowicz
- School of Engineering and Computer Science, The Hebrew University of Jerusalem, Jerusalem, Israel.
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13
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Barac DY, Reisner Y, Silberman M, Zeevi-Levin N, Danon A, Salomon O, Shoham M, Shilkrut M, Kostin S, Schaper J, Binah O. Mechanical load induced by glass microspheres releases angiogenic factors from neonatal rat ventricular myocytes cultures and causes arrhythmias. J Cell Mol Med 2009; 12:2037-51. [PMID: 19012730 PMCID: PMC4506169 DOI: 10.1111/j.1582-4934.2008.00193.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
In the present study, we tested the hypothesis that similar to other mechanical loads, notably cyclic stretch (simulating pre-load), glass microspheres simulating afterload will stimulate the secretion of angiogenic factors. Hence, we employed glass microspheres (average diameter 15.7 μm, average mass 5.2 ng) as a new method for imposing mechanical load on neonatal rat ventricular myocytes (NRVM) in culture. The collagen-coated microspheres were spread over the cultures at an estimated density of 3000 microspheres/mm2, they adhered strongly to the myocytes, and acted as small weights carried by the cells during their contraction. NRVM were exposed to either glass microspheres or to cyclic stretch, and several key angiogenic factors were measured by RT-PCR. The major findings were: (1) In contrast to other mechanical loads, such as cyclic stretch, microspheres (at 24 hrs) did not cause hypertrophy. (2) Further, in contrast to cyclic stretch, glass microspheres did not affect Cx43 expression, or the conduction velocity measured by means of the Micro-Electrode-Array system. (3) At 24 hrs, glass microspheres caused arrhythmias, probably resulting from early afterdepolarizations. (4) Glass microspheres caused the release of angiogenic factors as indicated by an increase in mRNA levels of vascular endothelial growth factor (80%), angiopoietin-2 (60%), transforming growth factor-β (40%) and basic fibroblast growth factor (15%); these effects were comparable to those of cyclic stretch. (5) As compared with control cultures, conditioned media from cultures exposed to microspheres increased endothelial cell migration by 15% (P<0.05) and endothelial cell tube formation by 120% (P<0.05), both common assays for angiogenesis. In conclusion, based on these findings we propose that loading cardiomyocytes with glass microspheres may serve as a new in vitro model for investigating the role of mechanical forces in angiogenesis and arrhythmias.
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Affiliation(s)
- D Y Barac
- Rappaport Family Institute for Research in the Medical Sciences, Ruth and Bruce Rappaport Faculty of Medicine, Haifa, Israel
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16
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Abstract
For a fetus diagnosed with a severe congenital anomaly, surgery may offer an alternative to abortion, intra-uterine death, or a life with disability. Expertise is limited however, to a few treatment centers worldwide, and there are many technical hurdles to overcome, including requirements for miniaturized instrumentation, real-time high-resolution imaging, and harmless fetal access. This article highlights recent practices in prenatal intervention and various initiatives to integrate robotics into the fetal operating room. While the number of potential patients is low, research for implementation of robotics in the field of fetal surgery is justified by the morbidity rates of current procedures, proven favorable outcomes with intervention, and the educational value with potential for extension to other medical disciplines.
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Affiliation(s)
- M Berris
- Medical Robotics Laboratory, Department of Mechanical Engineering, Technion - Israel Institute of Technology, Haifa, Israel.
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Shoham M, Lieberman IH, Benzel EC, Togawa D, Zehavi E, Zilberstein B, Roffman M, Bruskin A, Fridlander A, Joskowicz L, Brink-Danan S, Knoller N. Robotic assisted spinal surgery-from concept to clinical practice. ACTA ACUST UNITED AC 2007. [DOI: 10.1080/10929080701243981] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Zaaroor M, Kósa G, Peri-Eran A, Maharil I, Shoham M, Goldsher D. Morphological Study of the Spinal Canal Content for Subarachnoid Endoscopy. ACTA ACUST UNITED AC 2006; 49:220-6. [PMID: 17041833 DOI: 10.1055/s-2006-948000] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
STUDY DESIGN AND OBJECTIVE This study was designed to examine the morphology of the spinal dural sac and contents, using magnetic resonance imaging in order to define the inner geometrical dimensions that confine the manoeuvre of an endoscope inserted in the lumbar region and along the thoracic and cervical spine. BACKGROUND The morphology of the spine has been studied since the development of myelography. However, most studies have measured the diameters of the spinal cord only, not the size of the subarachnoid space. In addition, the few studies available on the subarachnoid space have focused on the cervical spine, leaving a near-complete dearth of data on the subarachnoid space dimensions along the thoracic spine. METHODS Based on MRI images of the spine from 42 patients, the dimensions of the spinal cord, dural sac, and subarachnoid space were measured at mid-vertebral and inter-vertebral disc levels. RESULTS It was found that at each selected transverse level, the subarachnoid space tends to be symmetrical on the right and left sides of the cord, and measures 2.5 mm on average. However, the posterior and anterior segments, measured on the mid-sagittal plane, are generally asymmetrical and vary widely in size, ranging from 1 to 5 mm. These measurements match those found in previous studies, where these are available. The coefficient of variance for the dimensions of the subarachnoid space is as high as 42.4%, while that for the dimensions of the spinal cord is 10-15%. CONCLUSIONS The findings presented here expand our knowledge of the spinal canal's morphology, and show that an endoscope designed to travel within the subarachnoid space must be smaller than 2.5 mm in diameter.
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Affiliation(s)
- M Zaaroor
- Department of Neurosurgery, Rambam Medical Center, Haifa, Israel
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Ben-Horin P, Shoham M. Singularity condition of six-degree-of-freedom three-legged parallel robots based on grassmann-cayley algebra. IEEE T ROBOT 2006. [DOI: 10.1109/tro.2006.878958] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Shamir R, Freiman M, Joskowicz L, Shoham M, Zehavi E, Shoshan Y. Robot-assisted image-guided targeting for minimally invasive neurosurgery: planning, registration, and in-vitro experiment. ACTA ACUST UNITED AC 2006; 8:131-8. [PMID: 16685952 DOI: 10.1007/11566489_17] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
This paper present a novel image-guided system for precise automatic targeting in keyhole minimally invasive neurosurgery. The system consists of a miniature robot fitted with a mechanical guide for needle/probe insertion. Intraoperatively, the robot is directly affixed to a head clamp or to the patient skull. It automatically positions itself with respect to predefined targets in a preoperative CT/MRI image following an anatomical registration with a intraoperative 3D surface scan of the patient facial features. We describe the preoperative planning and registration modules, and an in-vitro registration experiment of the entire system which yields a target registration error of 1.7 mm (std = 0.7 mm).
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Affiliation(s)
- R Shamir
- School of Eng. and Computer Science, The Hebrew Univ. of Jerusalem, Israel
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Vainstein V, Ginosar Y, Shoham M, Ranmar DO, Ianovski A, Agur Z. The complex effect of granulocyte colony-stimulating factor on human granulopoiesis analyzed by a new physiologically-based mathematical model. J Theor Biol 2005; 234:311-27. [PMID: 15784267 DOI: 10.1016/j.jtbi.2004.11.026] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2004] [Revised: 11/12/2004] [Accepted: 11/17/2004] [Indexed: 11/17/2022]
Abstract
Neutropenia, frequently a side effect of chemo- and radiotherapy, increases susceptibility to microbial infections and is a life-threatening condition. For realistically predicting drug treatment effects on granulopoiesis, we have constructed a new mathematical model of granulopoiesis in the bone marrow and in the peripheral blood, featuring cell cycle phase transition and detailed granulocyte-colony stimulating factor (G-CSF) pharmacokinetics (PK) and pharmacodynamics (PD), including intracellular second messenger. Using this model, in conjunction with clinical results, we evaluated the system parameters, implemented those in the model and successfully retrieved the results of several independent clinical experiments under a wide range of G-CSF regimens. Our results show that the introduction of G-CSF-controlled intracellular second messenger is indispensable for precise retrieval of the clinical results, and suggest that the half-life of this messenger varies between a single and multiple G-CSF administration schedules. In addition, our model provided reliable steady-state, as well as dynamic, estimations of human granulopoiesis parameters. These included an estimation of apoptosis index in the post-mitotic compartment, which corroborates previous results. At present the model is used for suggesting improved drug regimens.
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Affiliation(s)
- V Vainstein
- Institute for Medical Biomathematics, POB 282, Hagteena St. 10, Bene-Ataroth 60991, Israel.
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Agur Z, Arakelyan L, Belilty G, Dahan N, Harpak H, Kogan Y, Merbl Y, Rabinovich A, Shoham M, Ziv I. Application of the Virtual Cancer Patient Engine (VCPE) for improving oncological treatment desig. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Z. Agur
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - L. Arakelyan
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - G. Belilty
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - N. Dahan
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - H. Harpak
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - Y. Kogan
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - Y. Merbl
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - A. Rabinovich
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - M. Shoham
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
| | - I. Ziv
- Institute for Medical BioMathematics (IMBM), Bene Ataroth, Israel; Optimata ltd, Ramat-Gan, Israel
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Joskowicz L, Milgrom C, Shoham M, Yaniv Z, Simkin A. A robot-assisted system for long bone intramedullary distal locking: concept and preliminary results. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0531-5131(03)00250-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Abstract
AVP receptors represent a logical target for drug development. As a new class of therapeutic agents, orally active AVP analogs could be used to treat several human pathophysiological conditions including neurogenic diabetes insipidus, the syndrome of inappropriate secretion of AVP (SIADH), congestive heart failure, arterial hypertension, liver cirrhosis, nephrotic syndrome, dysmenorrhea, and ocular hypertension. By immunoprecipitation and immunoblotting, we elucidated the phosphorylation pattern of green fluorescent protein-tagged AVP receptors and showed interactions with the specific kinases PKC and GRK5 that are agonist-, time- and receptor subtype-dependent. The tyrosine residue of the NPWIY motif present in the 7th helix of AVP receptors is rapidly and transiently phosphorylated after agonist stimulation. This phosphorylation is instrumental in the genesis of the mitogenic cascade linked to the activation of this receptor, presumably by establishing key intramolecular contacts and by participating in the creation of a scaffold of proteins that produce the activation of downstream kinases. The random screening of chemical entities and optimization of lead compounds recently resulted in the development of orally active non-peptide AVP receptor agonists and antagonists. Furthermore, the identification of the molecular determinants of receptor-ligand interactions should facilitate the development of more potent and very selective orally active compounds via the approach of structure-based drug design. We developed three-dimensional molecular docking models of peptide and non-peptide ligands to the human V1 vascular, V2 renal and V3 pituitary AVP receptors. Docking of the peptide hormone AVP to the receptor ligand binding pockets reflects its dual polar and non-polar structure, but is receptor subtype-specific. The characteristics of non-peptide AVP analogs docking to the receptors are clearly distinct from those of peptide analogs docking. Molecular modeling of the results of site-directed mutagenesis experiments performed in CHO cells stably transfected with the human AVP receptor subtypes revealed that non-peptide antagonists establish key contacts with a few amino acid residues of the receptor subtypes that are different from those involved in agonist binding. Moreover, these interactions are species-specific. These findings provide further understanding of the signal transduction pathways of AVP receptors and new leads for elucidation of drug-receptor interactions and optimization of drug design. NOTE TO THE READER: The recent cloning and molecular characterization of AVP/OT receptor subtypes call for the revision of their nomenclature. For the sake of clarity and reference to their main site of expression, we call the V1a receptor the V1 vascular receptor, the V2 receptor the V2 renal receptor and the V1b or V3 receptor the V3 pituitary receptor in the present review.
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Affiliation(s)
- M Thibonnier
- Departments of Medicine and Biochemistry, Case Western Reserve University School of Medicine, University Hospitals of Cleveland, Cleveland, OH, USA.
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Shoham M, Wu N, Soelaiman S, Dickman KR, Kosmidis AP, Li C, Jakes K. Crystal structure of colicin e3: implications for ribosome inactivation and cell entry. Acta Crystallogr A 2002. [DOI: 10.1107/s0108767302086518] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
Successful implementation of robot-assisted surgery (RAS) requires coherent integration of spatial image data with sensing and actuating devices, each having its own coordinate system. Hence, accurate estimation of the geometric relationships between relevant reference frames, known as registration, is a crucial procedure in all RAS applications. The purpose of this paper is to present a new registration scheme, along with the results of an experimental evaluation of a robot-assisted registration method for RAS applications in orthopedics. The accuracy of the proposed registration is appropriate for specified orthopedic surgical applications such as Total Knee Replacement. The registration method is based on a surface-matching algorithm that does not require marker implants, thereby reducing surgical invasiveness. Points on the bone surface are sampled by the robot, which in turn directs the surgical tool. This technique eliminates additional coordinate transformations to an external device (such as a digitizer), resulting in increased surgical accuracy. The registration technique was tested on an RSPR six-degrees-of-freedom parallel robot specifically designed for medical applications. A six-axis force sensor attached to the robot's moving platform enables fast and accurate acquisition of positions and surface normal directions at sampled points. Sampling with a robot probe was shown to be accurate, fast, and easy to perform. The whole procedure takes about 2 min, with the robot performing most of the registration procedures, leaving the surgeon's hands free. Robotic registration was shown to provide a flawless link between preoperative planning and robotic assistance during surgery.
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Affiliation(s)
- D Glozman
- Robotics Laboratory, Department of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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Abstract
STUDY DESIGN The anatomy of the lumbar vertebrae of 55 patients was measured by use of data provided by computed tomography. On the basis of these measurements, the location of puncture points and the orientation of the surgical instruments for pedicle, vertebral body, and disc entry points were calculated for open as well as percutaneous surgery. OBJECTIVE Normal anatomic variations of the lumbar spine were investigated to define the workspace for several spinal procedures and to define the workspace of a robot designed to guide the physician during those procedures. SUMMARY OF BACKGROUND Several comprehensive studies of vertebrae dimensions have been conducted in the past, but they lack several dimensions that are needed to determine the exact location of the entry point and orientation of the tool, in particular when a computerized guidance system is used. METHODS Fifty-five spinal columns (L1-L5, total 250 vertebrae) were measured by computed tomography. These data provide geometric relations that determine entry points and tool orientations for different spinal interventions. RESULTS The workspace for spinal operations was defined on the basis of anatomic data taken from computed tomography scans. The data included 15 measurements for each vertebra that defined its shape. The processed data provided puncture points for several spinal procedures in both open and percutaneous surgery. CONCLUSIONS This study provides additional information on vertebral structure needed to calculate accurately the entry point and tool orientation in various spinal procedures. These statistical data are also valuable for model and implant designs and for workspace specifications for a robot-assisted surgery system.
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Affiliation(s)
- A Wolf
- Department of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa, Israel.
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Shoham M, Müssig J, Shevack A, Arad T, Wittmann H, Yonath A. A new crystal form of large ribosomal subunits from Halobacterium marismortui. FEBS Lett 2001. [DOI: 10.1016/0014-5793(86)81042-0] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Shoham M, Dijḱ J, Reinhardt R, Wittmann-Liebold B. Purification and characterization of ribosomal proteins from the 30 S subunit of the extreme halophile Halobacterium marismortui. FEBS Lett 2001; 204:323-30. [DOI: 10.1016/0014-5793(86)80837-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Abstract
Colicins kill E. coli by a process that involves binding to a surface receptor, entering the cell, and, finally, intoxicating it. The lethal action of colicin E3 is a specific cleavage in the ribosomal decoding A site. The crystal structure of colicin E3, reported here in a binary complex with its immunity protein (IP), reveals a Y-shaped molecule with the receptor binding domain forming a 100 A long stalk and the two globular heads of the translocation domain (T) and the catalytic domain (C) comprising the two arms. Active site residues are D510, H513, E517, and R545. IP is buried between T and C. Rather than blocking the active site, IP prevents access of the active site to the ribosome.
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Affiliation(s)
- S Soelaiman
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
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Abstract
We report the use of methylotrophic yeast Pichia pastoris as a host to efficiently express complement control protein repeats (CCPs) 1-4 of mouse decay accelerating factor (DAF, CD55) as a soluble protein. With this system, the mouse DAF CCP1-4-active-domain-containing module linked to a 6x His tag at its C terminus was secreted into the culture supernatant at 15 mg/L after 24 h of induction with methanol. A mouse DAF CCP1-4 mutant protein in which its two potential N-glycosylation sites were deleted by changing Asn(187) and Asn(262) to Gln was also produced. Using Ni(2+)-immobilized agarose affinity chromatography, the recombinant mouse DAF modules with their 6x His tags could be one-step isolated to SDS-PAGE purity. Polyclonal antibody against native mouse DAF CCP1-4 was raised by immunizing NZW rabbits with the purified product. Measurements of the bioactivities of the wild-type and mutant mouse DAF proteins in C3b uptake assays showed no differences in regulatory activities in either the classical or the alternative pathways. With the use of the mutant DAF protein, small rod-shaped crystals were produced and preliminary data obtained. The production of large quantities of functional recombinant mouse DAF CCP1-4 modules and their antibody offers the opportunity to study DAF structure and DAF function in vivo.
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Affiliation(s)
- F Lin
- Institute of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA
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Abstract
The neurohypophysial hormone arginine vasopressin (AVP) is a cyclic nonpeptide whose actions are mediated by the stimulation of specific G protein--coupled membrane receptors pharmacologically classified into V1-vascular (V1R), V2-renal (V2R) and V3-pituitary (V3R) AVP receptor subtypes. The random screening of chemical compounds and optimization of lead compounds recently resulted in the development of orally active nonpeptide AVP receptor antagonists. Potential therapeutic uses of AVP receptor antagonists include (a) the blockade of V1-vascular AVP receptors in arterial hypertension, congestive heart failure, and peripheral vascular disease; (b) the blockade of V2-renal AVP receptors in the syndrome of inappropriate vasopressin secretion, congestive heart failure, liver cirrhosis, nephrotic syndrome and any state of excessive retention of free water and subsequent dilutional hyponatremia; (c) the blockade of V3-pituitary AVP receptors in adrenocorticotropin-secreting tumors. The pharmacological and clinical profile of orally active nonpeptide vasopressin receptor antagonists is reviewed here.
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Affiliation(s)
- M Thibonnier
- Department of Medicine, Case Western Reserve University School of Medicine and University Hospitals of Cleveland, Cleveland, Ohio 44106-4951, USA.
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Thibonnier M, Coles P, Conarty DM, Plesnicher CL, Shoham M. A molecular model of agonist and nonpeptide antagonist binding to the human V(1) vascular vasopressin receptor. J Pharmacol Exp Ther 2000; 294:195-203. [PMID: 10871312] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023] Open
Abstract
The affinity of the nonpeptide antagonist OPC-21268 is greater for the rat V(1) arginine vasopressin (AVP) receptor (V(1)R) than for the human V(1)R. Site-specific mutagenesis was carried out to identify the residues that determine interspecies selectivity for nonpeptide antagonist binding. The introduction of rat amino acids in position 224, 310, 324, or 337 of the human V(1)R sequence dramatically altered OPC-21268 affinity for the receptor, whereas binding of AVP, the peptide V(1)R antagonist d(CH(2))(5)Tyr(Me)AVP, and the nonpeptide V(1)R antagonist SR49059 was not altered by these mutations. Computer modeling explained the mutagenesis results. Docking of OPC-21268 onto a homology-built model of the V(1)R receptor yielded a model for the bound ligand in which the hydrophobic part is deeply embedded in the transmembrane region, whereas the polar part is located on the surface of the extracellular side. The increased affinity of the G337A mutant is due to two additional van der Waals contacts of the alanine methyl group with carbon atoms on the antagonist. The I310V mutant reduces the hydrophobicity in the vicinity of the polar oxygen atom of the antagonist. The I224V mutant relieves overcrowding in a hydrophobic binding pocket involving the aromatic residues Trp(175), Phe(179), Phe(307), and Trp(304). Finally, the E324D mutant enables the formation of a hydrogen bond of the carboxylate side chain with the amide side chain of Gln(311), which in turn forms a hydrogen bond with the N57 nitrogen atom of OPC-21268. Thus, a few residues, distinct from those involved in agonist binding, control interspecies selectivity toward OPC-21268 nonpeptide antagonist binding.
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Affiliation(s)
- M Thibonnier
- Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4951, USA.
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Abstract
The crystal structure of a thermophilic alcohol dehydrogenase (TBAD) from Thermoanaerobacter brockii has been determined in a binary complex with sec-butanol as substrate to a resolution of 3.0 A. Van der Waals interactions of the carbon C1 atom of sec-butanol with atoms in His59, Ala85, Trp110, Asp150, and Leu294 account for the substrate preference of this enzyme for secondary over primary alcohols. A crevice from the surface to the active site provides access for substrates and products. This opening is lined with the hydrophobic residues Ile49, Leu107, Trp110, Tyr267, Leu294 as well as Cys283 and Met285 from another molecule within the tetrameric assembly. This might explain the tolerance of this enzyme toward organic solvents. The zinc ion occupies a position in the active site, which is too remote for direct interaction with the alcohol group. A mechanism is suggested whereby the introduction of NADP would trigger a displacement of the zinc ion to its catalytic site. Features important for the unusually high melting temperature of 98 degrees C are suggested by comparison to the crystal structure of a highly homologous mesophilic alcohol dehydrogenase from Clostridium beijerinckii (CBAD). The thermophilic enzyme has a more hydrophilic exterior, a more hydrophobic interior, a smaller surface area, more prolines, alanines, and fewer serines than CBAD. Furthermore, in the thermophilic enzyme the number of all types of intersubunit interactions in these tetrameric enzymes is increased: more salt bridges, hydrogen bonds, and hydrophobic interactions. All these effects combined can account for the higher melting temperature of the thermophilic enzyme.
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Affiliation(s)
- C Li
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, Ohio 44106-4935, USA
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Abstract
BACKGROUND Colicins are antibiotic-like proteins of Escherichia coli that kill related strains. Colicin E3 acts as an RNase that specifically cleaves 16S rRNA, thereby inactivating the ribosomes in the infected cell. The producing organism is protected against colicin E3 by a specific inhibitor, the immunity protein Im3, which forms a tight 1:1 complex with colicin E3 and renders it inactive. Crystallographic studies on colicin E3 and Im3 have been undertaken to unravel the structural basis for the ribonucleolytic activity and its inhibition. RESULTS The crystal structure of Im3 has been determined to a resolution of 1.8 A. The structure consists of a four-standard antiparallel beta sheet flanked by three alpha helices on one side of the sheet. Thr7, Phe9, Phe16 and Phe74 form a hydrophobic cluster on the surface of the protein in the vicinity of Cys47. This cluster is part of a putative binding pocket which also includes nine polar residues. CONCLUSIONS The putative binding pocket of Im3 is the probable site of interaction with colicin E3. The six acidic residues in the pocket may interact with some of the numerous basic residues of colicin E3. The involvement of hydrophobic moieties in the binding is consistent with the observation that the tight complex can only be dissociated by denaturation. The structure of Im3 resembles those of certain nucleic acid binding proteins, in particular domain II of topoisomerase I and RNA-binding proteins that contain the ribonucleoprotein (RNP) sequence motif. This observation suggests that Im3 has a nucleic acid binding function in addition to binding colicin E3.
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Affiliation(s)
- C Li
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106-4935, USA
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Levin O, Mizrahi J, Shoham M. Standing sway: iterative estimation of the kinematics and dynamics of the lower extremities from force-plate measurements. Biol Cybern 1998; 78:319-327. [PMID: 9652081 DOI: 10.1007/s004220050436] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In this study, a model for the estimation of the dynamics of the lower extremities in standing sway from force plate data only is presented. A three-dimensional, five-segment, four-joint model of the human body was used to describe postural standing sway dynamics. Force-plate data of the reactive forces and centers of pressure were measured bilaterally. By applying the equations of motion to these data, the transversal trajectory of the center of gravity (CG) of the body was resolved in the sagittal and coronal planes. An inverse kinematics algorithm was used to evaluate the kinematics of the body segments. The dynamics of the segments was then resolved by using the Newton-Euler equations, and the model's estimated dynamic quantities of the distal segments were compared with those actually measured. Differences between model and measured dynamics were calculated and minimized, using an iterative algorithm to re-estimate joint positioning and anthropometric properties. The above method was tested with a group of 11 able-bodied subjects, and the results indicated that the relative errors obtained in the final iteration were of the same order of magnitude as those reported for closed loop problems involved in direct kinematic measurements of human gait.
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Affiliation(s)
- O Levin
- Department of Biomedical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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Roth BL, Shoham M, Choudhary MS, Khan N. Identification of conserved aromatic residues essential for agonist binding and second messenger production at 5-hydroxytryptamine2A receptors. Mol Pharmacol 1997; 52:259-66. [PMID: 9271348 DOI: 10.1124/mol.52.2.259] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Several models of agonist binding to G protein-coupled 5-hydroxytryptamine [5-HT] (serotonin) receptors have highlighted the potential importance of highly conserved aromatic residues for ligand binding and agonist efficacy. In this study, we tested these models by constructing and characterizing a number of point mutations of conserved and nonconserved aromatic residues using the 5-HT2A receptor as a model system. Mutations of three highly conserved tryptophans (W200A, W336A, and W367A) proposed to reside near the binding pocket markedly reduced agonist affinity and efficacy at 5-HT2A receptors. Mutations of two other highly conserved aromatic residues postulated to be near the agonist binding site (F340L and Y370A) also had dramatic effects on agonist binding and efficacy. Point mutations of neighboring conserved phenylalanines (F339L and F365L) had minimal effects on agonist binding, although the F365L mutation diminished agonist efficacy. Finally, mutations of two nonconserved aromatic residues (F125L and F383A) not predicted to be near the binding pocket had no effects on agonist binding, potency, or efficacy. Our results are best explained by models that suggest that helices III, V, VI, and VII can form a unit of interacting helices in which highly conserved aromatic residues are oriented toward the center of the helical aggregate to form an aromatic pocket. In addition, our novel results identify a series of aromatic residues essential for agonist-induced second messenger production. These results demonstrate that highly conserved aromatic residues residing in neighboring helices provide the optimum environment for both agonist binding and activation of 5-HT2A receptors.
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Affiliation(s)
- B L Roth
- Department of Psychiatry, Case Western Reserve University Medical School, Cleveland, Ohio 44106-4935, USA.
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Affiliation(s)
- F Gerhards
- Center for Psychobiological and Psychosomatic Research, University of Trier, Germany.
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Abstract
A model of the regulatory region of human decay accelerating factor (DAF) was built based on the known coordinates of a fragment of the structurally and functionally homologous serum protein, factor H. According to this model, the four short consensus repeats (SCRs) in DAF are arranged in a helical fashion. A positively charged surface area on SCRs 2 and 3, two of the three repeating units essential for function, is postulated to be the primary recognition site for the C3 convertases C4b2a and C3bBb. This area encompasses a cavity on SCR 2, as well as part of the groove on the SCR 2-SCR 3 interface. Two additional surface depressions are centered around the C-terminal disulfide bridges of SCRs 3 and 4. These are likely to provide additional ligand binding sites. Based on this model in conjunction with sequence homology to the Ba fragment of factor B, a mechanism of DAF's accelerated convertase decay action is postulated.
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Affiliation(s)
- L Kuttner-Kondo
- Institute of Pathology, Case Western Reserve University, Cleveland, OH 44106-4935, USA
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Walter RL, Ealick SE, Friedman AM, Blake RC, Proctor P, Shoham M. Multiple wavelength anomalous diffraction (MAD) crystal structure of rusticyanin: a highly oxidizing cupredoxin with extreme acid stability. J Mol Biol 1996; 263:730-51. [PMID: 8947572 DOI: 10.1006/jmbi.1996.0612] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The X-ray crystal structure of the oxidized form of the extremely stable and highly oxidizing cupredoxin rusticyanin from Thiobacillus ferrooxidans has been determined by the method of multiwavelength anomalous diffraction (MAD) and refined to 1.9 A resolution. Like other cupredoxins, rusticyanin is a copper-containing metalloprotein, which is composed of a core beta-sandwich fold. In rusticyanin the beta-sandwich is composed of a six- and a seven-stranded beta-sheet. Also like other cupredoxins, the copper ion is coordinated by a cluster of four conserved residues (His85, Cys138, His143, Met148) arranged in a distorted tetrahedron. Rusticyanin has a redox potential of 680 mV, roughly twice that of any other cupredoxin, and it is optimally active at pH values < or = 2. By comparison with other cupredoxins, the three-dimensional structure of rusticyanin reveals several possible sources of the chemical differences, including more ordered secondary structure and more intersheet connectivity than other cupredoxins. The acid stability and redox potential of rusticyanin may also be enhanced over other cupredoxins by a more extensive internal hydrogen bonding network and by more extensive hydrophobic interactions surrounding the copper binding site. Finally, reduction in the number of charged residues surrounding the active site may also make a major contribution to acid stability. We propose that the resulting rigid copper binding site, which is constrained by the surrounding hydrophobic environment, structurally and electronically favours Cu(I). We propose that the two extreme chemical properties of rusticyanin are interrelated; the same unique structural features that enhance acid stability also lead to elevated redox potential.
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Affiliation(s)
- R L Walter
- Section of Biochemistry, Cell & Molecular Biology, Cornell University, Ithaca, NY 14853, USA
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Shoham M, Zhao D. Adaptation to extreme environments: insights from halophilic ferredoxin and acidophilic rusticyanin. Acta Crystallogr A 1996. [DOI: 10.1107/s0108767396090198] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Frolow F, Harel M, Sussman JL, Mevarech M, Shoham M. Insights into protein adaptation to a saturated salt environment from the crystal structure of a halophilic 2Fe-2S ferredoxin. Nat Struct Biol 1996; 3:452-8. [PMID: 8612076 DOI: 10.1038/nsb0596-452] [Citation(s) in RCA: 178] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
Haloarcula marismortui is an archaebacterium that flourishes in the world's saltiest body of water, the Dead Sea. The cytosol of this organism is a supersaturated salt solution in which proteins are soluble and active. The crystal structure of a 2Fe-2S ferredoxin from H. marismortui determined at 1.9 A is similar to those of plant-type 2Fe-2S ferredoxins of known structure, with two important distinctions. The entire surface of the protein is coated with acidic residues except for the vicinity of the iron-sulphur cluster, and there is an insertion of two amphipathic helices near the N-terminus. These form a separate hyperacidic domain whose postulated function to provide extra surface carboxylates for solvation. These data and the fact that bound surface water molecules have on the average 40% more hydrogen bonds than in a typical non-halophilic protein crystal structure support the notion that haloadaptation involves better water binding capacity.
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Affiliation(s)
- F Frolow
- Department of Structural Biology, The Weizmann Institute of Science, Rehovot, Israel
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43
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Abstract
Dimerization represents a key regulatory step in the function of basic helix-loop-helix transcriptional factors. In many instances tissue-specific basic helix-loop-helix proteins, such as the hematopoietic factor SCL/tal or the myogenic factor MyoD, interact with ubiquitously expressed basic helix-loop-helix proteins, such as E2A or E2-2. Such dimerization is necessary for high affinity, sequence-specific DNA binding. Previous biochemical and structural studies have shown the helix-loop-helix region to be necessary and sufficient for this interaction. In the present study, we analyzed the relative affinities of various helix-loop-helix interactions using the yeast two-hybrid system. The relative affinities of selected helix-loop-helix species for the partner protein E2-2 were as follows: Id2 > MyoD > SCL/tal. Mutants of SCL/tal with increased affinity for E2-2 were selected from a library of randomly mutated basic helix-loop-helix domains. The amino acid changes in these high affinity versions of SCL/tal introduced residues that resembled those in the corresponding positions of the Id proteins and MyoD. One of the mutants, SCL 12, also contained mutations in highly conserved residues previously thought to be necessary for dimerization. This mutant of SCL demonstrated diminished temperature sensitivity in in vitro interaction assays as compared with the wild type protein. Computational modeling of helix-loop-helix dimers provides an explanation for the increased dimerization affinity of SCL mutant 12.
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Affiliation(s)
- A N Goldfarb
- Department of Pathology, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106, USA.
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Shoham M, Scherf T, Anglister J, Levitt M, Merritt EA, Hol WG. Structural diversity in a conserved cholera toxin epitope involved in ganglioside binding. Protein Sci 1995; 4:841-8. [PMID: 7545048 PMCID: PMC2143124 DOI: 10.1002/pro.5560040503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Cholera is a widespread disease for which there is no efficient vaccine. A better understanding of the conformational rearrangements at the epitope might be very helpful for the development of a good vaccine. Cholera toxin (CT) as well as the closely related heat-labile toxin from Escherichia coli (LT) are composed of two subunits, A and B, which form an oligomeric assembly AB5. Residues 50-64 on the surface of the B subunits comprise a conserved loop (CTP3), which is involved in saccharide binding to the receptor on epithelial cells. This loop exhibits remarkable conformational plasticity induced by environmental constraints. The crystal structure of this loop is compared in the free and receptor-bound toxins as well as in the crystal and solution structures of a complex with TE33, a monoclonal antibody elicited against CTP3. In the toxins this loop forms an irregular structure connecting a beta-strand to the central alpha-helix. Ser 55 and Gln 56 exhibit considerable conformational variability in the five subunits of the unliganded toxins. Saccharide binding induces a change primarily in Ser 55 and Gln 56 to a conformation identical in all five copies. Thus, saccharide binding confers rigidity upon the loop. The conformation of CTP3 in complex with TE33 is quite different. The amino-terminal part of CTP3 forms a beta-turn that fits snugly into a deep binding pocket on TE33, in both the crystal and NMR-derived solution structure. Only 8 and 12 residues out of 15 are seen in the NMR and crystal structures, respectively. Despite these conformational differences, TE33 is cross-reactive with intact CT, albeit with a thousandfold decrease in affinity. This suggests a different interaction of TE33 with intact CT.
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Affiliation(s)
- M Shoham
- Case Western Reserve University, School of Medicine, Department of Biochemistry, Cleveland, Ohio 44106-4935, USA
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Abstract
A dynamic model of the biomechanics of the index finger for flexion-extension and abduction-adduction motion is introduced. The model takes into account all the tendons in the finger and relates to their varying moment arms during motion. A new set of moment arm coefficients and elongation equations is derived based on experimental measurements of previous studies. Constraint equations using variable coefficients are introduced and an optimization approach used to obtain the tendon forces required for any given motion and external force. The model and optimization approach are tested with data from a rapid pinch experiment as well as a hypothetical disc rotation. Good correlation is obtained with respect to electromyographic data in the literature.
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Affiliation(s)
- N Brook
- Faculty of Mechanical Engineering, Technion-Israel Institute of Technology, Haifa, Israel
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46
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Abstract
Cholera toxin peptide 3 (CTP3) is a 15-residue peptide corresponding in sequence to an immunogenic loop on the surface of the B-subunits of both cholera toxin and the heat-labile toxin from Escherichia coli. TE33 is the Fab fragment of a monoclonal antibody elicited against CTP3. The crystal structure of the TE33-CTP3 complex at 2.3 A resolution reveals an antigen-binding pocket, 13 A deep and 13 A wide, which is lined with many aromatic residues. The N-terminal portion of the peptide antigen CTP3 forms a type II beta-turn that fits snugly into this pocket. At gln7 the peptide backbone of CTP3 forms a kink followed by an extended C-terminal chain that seals off the cleft and buries the beta-turn underneath it. All six complementarity-determining regions of TE33 contribute to the binding of CTP3. The antibody-peptide contacts include, in addition to van der Waals' interactions and hydrogen bonds, also one salt bridge and one water molecule, which mediates the interaction.
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Affiliation(s)
- M Shoham
- Case Western Reserve University, School of Medicine, Department of Biochemistry, Cleveland, OH 44106-4935
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Zhang Z, Djebli A, Shoham M, Frolow F, Peretz M, Burstein Y. Crystal parameters of an alcohol dehydrogenase from the extreme thermophile Thermoanaerobium brockii. J Mol Biol 1993; 230:353-5. [PMID: 8450548 DOI: 10.1006/jmbi.1993.1149] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A bacterial thermophilic alcohol dehydrogenase which is stable and active at 85 degrees C, has been crystallized by vapor diffusion from solutions of polyethylene glycol. A monoclinic crystal form diffracts to 2.8 A resolution and belongs to space group C2 with unit cell dimensions a = 139.0 A, b = 137.4 A, c = 80.9 A and beta = 93.23 degrees. The asymmetric unit contains four molecules which exhibit 222 point symmetry. A second crystal form is orthohombic, space group P2(1)2(1)2 with unit cell dimensions a = 168.0 A, b = 123.0 A, c = 80.0 A, and it diffracts to 3.2 A resolution.
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Affiliation(s)
- Z Zhang
- Case Western Reserve University, School of Medicine, Department of Biochemistry, Cleveland, Ohio 44106-4935
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Abstract
Rusticyanin is a 16.5 kDa type I blue copper protein isolated from Thiobacillus ferrooxidans. This organism can grow on Fe2+ as its sole energy source. Rusticyanin is thought to be a principal component in the iron respiratory electron transport chain of T. ferrooxidans. As a component of the periplasmic space of an acidophilic bacterium, rusticyanin is remarkably stable at acidic pH. It is redox-active down to pH 0.2. Crystals of rusticyanin have been grown from solutions of PEG 8000 by the hanging-drop vapor diffusion method. The crystals are orthorhombic, space group P2(1)2(1)2(1), with unit cell dimensions a = 32.36 A, b = 60.37 A, c = 74.60 A. The crystals diffract to 2.0 A resolution and they are stable in the X-ray beam for at least two days.
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Affiliation(s)
- A Djebli
- Case Western Reserve University, School of Medicine, Department of Biochemistry, Cleveland, OH 44106-4935
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49
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Abstract
The hypothesis that dihydrolipoamide dehydrogenases (E3s) have tertiary structures very similar to that of human glutathione reductase (GR) was tested in detail by three separate criteria: (1) by analyzing each putative secondary structural element for conservation of appropriate polar/nonpolar regions, (2) by detailed comparison of putative active site residues in E3s with their authentic counterparts in human GR, and (3) by comparison of residues at the putative dimeric interface of the E3s with the authentic residues in GR. All three criteria are satisfied in a convincing way for the 7 E3s that were considered, supporting the conclusion that the structural scaffolding and the overall tertiary structure (which determines the location of functional sites and residues) are remarkably similar for the E3s and for GR. These analyses together with the crystal structures of human erythrocyte GR formed the basis for construction of a molecular model for human E3. The cofactor FAD and the substrates NAD and lipoic acid were also included in the model. Unexpectedly, the surface residues in the cleft that holds the lipoamide were found to be highly charged and predominantly acidic, allowing us to predict that the region around the lipoamide in the subunit should be basic in nature. The molecular model can be tested by site-directed mutagenesis of residues predicted to be in the dihydrolipoamide acetyltransferase subunit binding cleft.
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Affiliation(s)
- J E Jentoft
- Department of Biochemistry, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106
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50
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Abstract
TE33 is an Fab fragment of a monoclonal antibody raised against a 15-residue long peptide (CTP3), corresponding in sequence to residues 50-64 of the cholera toxin B subunit. Crystals of the complex between TE33 and CTP3 have been grown from 20% (w/v) polyethylene glycol-8000 at pH 4.0. The crystals are orthorhombic, space group P2(1)2(1)2, with unit cell dimensions a = 104.15, b = 110.61, and c = 40.68 A. X-Ray data have been collected to a resolution of 2.3 A. The asymmetric unit contains one molecule of Fab and one molecule of CTP3. The presence of CTP3 has been demonstrated by fluorescence quenching of the dissolved crystal after X-ray data collection. A molecular replacement solution was found based on the coordinates of DB3, an antiprogesterone Fab fragment.
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Affiliation(s)
- M Shoham
- Department of Biochemistry, Case Western Reserve University, School of Medicine, Cleveland, Ohio 44106
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