1
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Servant G, Kenakin T. A Pharmacological perspective on the temporal properties of sweeteners. Pharmacol Res 2024; 204:107211. [PMID: 38744400 DOI: 10.1016/j.phrs.2024.107211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2024] [Revised: 05/06/2024] [Accepted: 05/09/2024] [Indexed: 05/16/2024]
Abstract
Several non-caloric sweeteners exhibit a delay in sweetness onset and a sweetness linger after sampling. These temporal properties are thought to be the result of non-specific interactions with cell membranes and proteins in the oral cavity. Data and analysis presented in this report also support the potential involvement of receptor affinity and binding kinetics to this phenomenon. In general, affected sweeteners exhibit distinctly higher binding affinity compared to carbohydrate sweeteners, which do not have temporal issues. In addition, binding kinetic simulations illustrate much slower receptor binding association and dissociation kinetics for a set of non-caloric sweeteners presenting temporal issues, in comparison to carbohydrate sweeteners. So, the higher affinity of some non-caloric sweeteners, dictating lower use levels, and affecting binding kinetics, could contribute to their delay and linger in sweetness perception. Simple pharmacology principles could explain, at least in part, some of the temporal issues of sweeteners.
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Affiliation(s)
- Guy Servant
- dsm-firmenich, 10636 Scripps Summit Court #201, San Diego, CA 92131, USA.
| | - Terry Kenakin
- Department of Pharmacology, University of North Carolina School of Medicine, 120 Mason Farm Rd., 4042 Genetic Medicine CB #7365, Chapel Hill, NC 27599, USA
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2
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Ferreira PA. Nucleocytoplasmic transport at the crossroads of proteostasis, neurodegeneration and neuroprotection. FEBS Lett 2023; 597:2567-2589. [PMID: 37597509 DOI: 10.1002/1873-3468.14722] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 08/04/2023] [Accepted: 08/05/2023] [Indexed: 08/21/2023]
Abstract
Nucleocytoplasmic transport comprises the multistep assembly, transport, and disassembly of protein and RNA cargoes entering and exiting nuclear pores. Accruing evidence supports that impairments to nucleocytoplasmic transport are a hallmark of neurodegenerative diseases. These impairments cause dysregulations in nucleocytoplasmic partitioning and proteostasis of nuclear transport receptors and client substrates that promote intracellular deposits - another hallmark of neurodegeneration. Disturbances in liquid-liquid phase separation (LLPS) between dense and dilute phases of biomolecules implicated in nucleocytoplasmic transport promote micrometer-scale coacervates, leading to proteinaceous aggregates. This Review provides historical and emerging principles of LLPS at the interface of nucleocytoplasmic transport, proteostasis, aging and noxious insults, whose dysregulations promote intracellular aggregates. E3 SUMO-protein ligase Ranbp2 constitutes the cytoplasmic filaments of nuclear pores, where it acts as a molecular hub for rate-limiting steps of nucleocytoplasmic transport. A vignette is provided on the roles of Ranbp2 in nucleocytoplasmic transport and at the intersection of proteostasis in the survival of photoreceptor and motor neurons under homeostatic and pathophysiological environments. Current unmet clinical needs are highlighted, including therapeutics aiming to manipulate aggregation-dissolution models of purported neurotoxicity in neurodegeneration.
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Affiliation(s)
- Paulo A Ferreira
- Department of Ophthalmology, Department of Pathology, Duke University Medical Center, NC, Durham, USA
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3
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Risitano AM, Frieri C, Urciuoli E, Marano L. The complement alternative pathway in paroxysmal nocturnal hemoglobinuria: From a pathogenic mechanism to a therapeutic target. Immunol Rev 2023; 313:262-278. [PMID: 36110036 PMCID: PMC10087358 DOI: 10.1111/imr.13137] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is a rare clonal, not malignant, hematological disease characterized by intravascular hemolysis, thrombophilia and bone marrow failure. While this latter presentation is due to a T-cell mediated auto-immune disorder resembling acquired aplastic anemia, the first two clinical presentations are largely driven by the complement pathway. Indeed, PNH is characterized by a broad impairment of complement regulation on affected cells, which is due to the lack of the complement regulators CD55 and CD59. The deficiency of these two proteins from PNH blood cells is due to the somatic mutation in the phosphatidylinositol N-acetylglucosaminyltransferase subunit A gene causing the disease, which impairs the surface expression of all proteins linked via the glycosylphosphatidylinositol anchor. The lack of the complement regulators CD55 and CD59 on PNH erythrocytes accounts for the hallmark of PNH, which is the chronic, complement-mediated intravascular hemolysis. This hemolysis results from the impaired regulation of the alternative pathway upstream in the complement cascade, as well as of the downstream terminal pathway. PNH represented the first indication for the development of anti-complement agents, and the therapeutic interception of the complement cascade at the level of C5 led to remarkable changes in the natural history of the disease. Nevertheless, the clinical use of an inhibitor of the terminal pathway highlighted the broader derangement of complement regulation in PNH, shedding light on the pivotal role of the complement alternative pathway. Here we review the current understanding of the role of the alternative pathway in PNH, including the emergence of C3-mediated extravascular hemolysis in PNH patients on anti-C5 therapies. These observations provide the rationale for the development of novel complement inhibitors for the treatment of PNH. Recent preclinical and clinical data on proximal complement inhibitors intercepting the alternative pathway with the aim of improving the treatment of PNH are discussed, together with their clinical implications which are animating a lively debate in the scientific community.
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Affiliation(s)
- Antonio M Risitano
- AORN San Giuseppe Moscati, Avellino, Italy.,Federico II University of Naples, Naples, Italy.,Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation, Leiden, Netherlands
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4
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Lamers C, Xue X, Smieško M, van Son H, Wagner B, Berger N, Sfyroera G, Gros P, Lambris JD, Ricklin D. Insight into mode-of-action and structural determinants of the compstatin family of clinical complement inhibitors. Nat Commun 2022; 13:5519. [PMID: 36127336 PMCID: PMC9488889 DOI: 10.1038/s41467-022-33003-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/17/2022] [Indexed: 12/04/2022] Open
Abstract
With the addition of the compstatin-based complement C3 inhibitor pegcetacoplan, another class of complement targeted therapeutics have recently been approved. Moreover, compstatin derivatives with enhanced pharmacodynamic and pharmacokinetic profiles are in clinical development (e.g., Cp40/AMY-101). Despite this progress, the target binding and inhibitory modes of the compstatin family remain incompletely described. Here, we present the crystal structure of Cp40 complexed with its target C3b at 2.0-Å resolution. Structure-activity-relationship studies rationalize the picomolar affinity and long target residence achieved by lead optimization, and reveal a role for structural water in inhibitor binding. We provide explanations for the narrow species specificity of this drug class and demonstrate distinct target selection modes between clinical compstatin derivatives. Functional studies provide further insight into physiological complement activation and corroborate the mechanism of its compstatin-mediated inhibition. Our study may thereby guide the application of existing and development of next-generation compstatin analogs.
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Affiliation(s)
- Christina Lamers
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
- Institute of Drug Discovery, Faculty of Medicine, Leipzig University, Brüderstrasse 34, 04103, Leipzig, Germany
| | - Xiaoguang Xue
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584, Utrecht, The Netherlands
| | - Martin Smieško
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Henri van Son
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584, Utrecht, The Netherlands
| | - Bea Wagner
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland
| | - Nadja Berger
- Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd, Philadelphia, 19104, PA, USA
| | - Georgia Sfyroera
- Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd, Philadelphia, 19104, PA, USA
| | - Piet Gros
- Department of Chemistry, Faculty of Science, Utrecht University, Padualaan 8, 3584, Utrecht, The Netherlands
| | - John D Lambris
- Department of Pathology & Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd, Philadelphia, 19104, PA, USA.
| | - Daniel Ricklin
- Department of Pharmaceutical Sciences, University of Basel, Klingelbergstrasse 50, 4056, Basel, Switzerland.
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5
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Abstract
Peptides have traditionally been perceived as poor drug candidates due to unfavorable characteristics mainly regarding their pharmacokinetic behavior, including plasma stability, membrane permeability and circulation half-life. Nonetheless, in recent years, general strategies to tackle those shortcomings have been established, and peptides are subsequently gaining increasing interest as drugs due to their unique ability to combine the advantages of antibodies and small molecules. Macrocyclic peptides are a special focus of drug development efforts due to their ability to address so called ‘undruggable’ targets characterized by large and flat protein surfaces lacking binding pockets. Here, the main strategies developed to date for adapting peptides for clinical use are summarized, which may soon help usher in an age highly shaped by peptide-based therapeutics. Nonetheless, limited membrane permeability is still to overcome before peptide therapeutics will be broadly accepted.
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6
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Risitano AM, Peffault de Latour R, Marano L, Frieri C. Discovering C3 targeting therapies for paroxysmal nocturnal hemoglobinuria: Achievements and pitfalls. Semin Immunol 2022; 59:101618. [PMID: 35764467 DOI: 10.1016/j.smim.2022.101618] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 05/26/2022] [Accepted: 06/08/2022] [Indexed: 01/15/2023]
Abstract
The treatment of paroxysmal nocturnal hemoglobinuria (PNH) was revolutionized by the introduction of the anti-C5 agent eculizumab, which resulted in sustained control of intravascular hemolysis, leading to transfusion avoidance and hemoglobin stabilization in at least half of all patients. Nevertheless, extravascular hemolysis mediated by C3 has emerged as inescapable phenomenon in PNH patients on anti-C5 treatment, frequently limiting its hematological benefit. More than 10 years ago we postulated that therapeutic interception of the complement cascade at the level of C3 should improve the clinical response in PNH. Compstatin is a 13-residue disulfide-bridged peptide binding to both human C3 and C3b, eventually disabling the formation of C3 convertases and thereby preventing complement activation via all three of its activating pathways. Several generations of compstatin analogs have been tested in vitro, and their clinical evaluation has begun in PNH and other complement-mediated diseases. Pegcetacoplan, a pegylated form of the compstatin analog POT-4, has been investigated in two phase I/II and one phase III study in PNH patients. In the phase III study, PNH patients with residual anemia already on eculizumab were randomized to receive either pegcetacoplan or eculizumab in a head-to-head comparison. At week 16, pegcetacoplan was superior to eculizumab in terms of hemoglobin change from baseline (the primary endpoint), as well as in other secondary endpoints tracking intravascular and extravascular hemolysis. Pegcetacoplan showed a good safety profile, even though breakthrough hemolysis emerged as a possible risk requiring additional attention. Here we review all the available data regarding this innovative treatment that has recently been approved for the treatment of PNH.
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Affiliation(s)
- Antonio M Risitano
- AORN San Giuseppe Moscati Avellino, Italy; Federico II University of Naples, Naples, Italy; Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation, Leiden, Netherlands
| | - Regis Peffault de Latour
- Severe Aplastic Anemia Working Party of the European Society for Blood and Marrow Transplantation, Leiden, Netherlands; French Reference Center for Aplastic Anemia and Paroxysmal Nocturnal Hemoglobinuria, Saint-Louis Hospital and Université de Paris, Paris, France
| | | | - Camilla Frieri
- AORN San Giuseppe Moscati Avellino, Italy; Federico II University of Naples, Naples, Italy; French Reference Center for Aplastic Anemia and Paroxysmal Nocturnal Hemoglobinuria, Saint-Louis Hospital and Université de Paris, Paris, France
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7
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Compstatins: the dawn of clinical C3-targeted complement inhibition. Trends Pharmacol Sci 2022; 43:629-640. [PMID: 35090732 PMCID: PMC9553322 DOI: 10.1016/j.tips.2022.01.004] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2021] [Revised: 01/03/2022] [Accepted: 01/04/2022] [Indexed: 02/08/2023]
Abstract
Despite the growing recognition of the complement system as a major contributor to a variety of clinical conditions, the therapeutic arsenal has remained scarce. The introduction of an anti-C5 antibody in 2007 raised confidence in complement-targeted therapy. However, it became apparent that inhibition of late-stage effector generation might not be sufficient in multifactorial complement disorders. Upstream intervention at the level of C3 activation has therefore been considered promising. The approval of pegcetacoplan, a C3 inhibitor of the compstatin family, in 2021 served as critical validation of C3-targeted treatment. This review delineates the evolution of the compstatin family from its academic origins to the clinic and highlights current and potential future applications of this promising drug class in complement diseases.
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8
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Wang X, Li W. Development and Testing of Force Field Parameters for Phenylalanine and Tyrosine Derivatives. Front Mol Biosci 2021; 7:608931. [PMID: 33385013 PMCID: PMC7770134 DOI: 10.3389/fmolb.2020.608931] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 10/23/2020] [Indexed: 11/13/2022] Open
Abstract
Theoretical analyses are valuable for the exploration of the effects of unnatural amino acids on enzyme functions; however, many necessary parameters for unnatural amino acids remain lacking. In this study, we developed and tested force field parameters compatible with Amber ff14SB for 18 phenylalanine and tyrosine derivatives. The charge parameters were derived from ab initio calculations using the RESP fitting approach and then adjusted to reproduce the benchmark relative energies (at the MP2/TZ level) of the α- and β-backbones for each unnatural amino acid dipeptide. The structures optimized under the proposed force field parameters for the 18 unnatural amino acid dipeptides in both the α- and β-backbone forms were in good agreement with their QM structures, as the average RMSD was as small as 0.1 Å. The force field parameters were then tested in their application to seven proteins containing unnatural amino acids. The RMSDs of the simulated configurations of these unnatural amino acids were approximately 1.0 Å compared with those of the crystal structures. The vital interactions between proteins and unnatural amino acids in five protein–ligand complexes were also predicted using MM/PBSA analysis, and they were largely consistent with experimental observations. This work will provide theoretical aid for drug design involving unnatural amino acids.
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Affiliation(s)
- Xiaowen Wang
- Institute for Advanced Study, Shenzhen University, Shenzhen, China.,College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, China
| | - Wenjin Li
- Institute for Advanced Study, Shenzhen University, Shenzhen, China
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9
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Merrill SA, Brodsky RA. Complement-driven anemia: more than just paroxysmal nocturnal hemoglobinuria. HEMATOLOGY. AMERICAN SOCIETY OF HEMATOLOGY. EDUCATION PROGRAM 2018; 2018:371-376. [PMID: 30504334 PMCID: PMC6245985 DOI: 10.1182/asheducation-2018.1.371] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Atypical hemolytic uremic syndrome (aHUS); hemolysis, elevated liver function tests, and low platelets syndrome; and transplant-associated thrombotic microangiopathy are related conditions, in that many patients harbor germline heterozygous mutations in genes that regulate the alternative pathway of complement (APC). Penetrance is variable because development of clinically significant disease appears to require supervention of a process such as inflammation. Complement activation on the endothelial surfaces leads to endothelial damage, platelet consumption, microthrombi, and a mechanical hemolytic anemia with schistocytes. Paroxysmal nocturnal hemoglobinuria (PNH) is a clonal hematopoietic disease caused by expansion of a stem cell that harbors a somatic mutation in PIGA PIGA mutant blood cells are deficient in the complement regulator proteins CD55 and CD59, making them susceptible to intravascular hemolysis due to a failure to regulate the APC on erythrocytes. Eculizumab is a monoclonal antibody that binds to C5 and inhibits terminal complement by interfering with the cleavage of C5 by the C5 convertases. The drug is approved by the US Food and Drug Administration for the treatment of aHUS and PNH; however, a new generation of complement inhibitors that block C5 and other components of the complement cascade is showing promise in preclinical and clinical trials.
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MESH Headings
- Antibodies, Monoclonal, Humanized/therapeutic use
- Atypical Hemolytic Uremic Syndrome/blood
- Atypical Hemolytic Uremic Syndrome/drug therapy
- Atypical Hemolytic Uremic Syndrome/genetics
- CD55 Antigens/blood
- CD55 Antigens/genetics
- CD59 Antigens/blood
- CD59 Antigens/genetics
- Complement C5/antagonists & inhibitors
- Complement C5/genetics
- Complement C5/metabolism
- Complement C5 Convertase, Alternative Pathway/antagonists & inhibitors
- Complement C5 Convertase, Alternative Pathway/genetics
- Complement C5 Convertase, Alternative Pathway/metabolism
- Complement Pathway, Alternative/drug effects
- Complement Pathway, Alternative/genetics
- Hemoglobinuria, Paroxysmal/blood
- Hemoglobinuria, Paroxysmal/drug therapy
- Hemoglobinuria, Paroxysmal/genetics
- Hemolysis/drug effects
- Hemolysis/genetics
- Humans
- Membrane Proteins/blood
- Membrane Proteins/genetics
- Mutation
- Penetrance
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Affiliation(s)
- Samuel A Merrill
- Division of Hematology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
| | - Robert A Brodsky
- Division of Hematology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD
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10
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Berger N, Alayi TD, Resuello RRG, Tuplano JV, Reis ES, Lambris JD. New Analogs of the Complement C3 Inhibitor Compstatin with Increased Solubility and Improved Pharmacokinetic Profile. J Med Chem 2018; 61:6153-6162. [PMID: 29920096 DOI: 10.1021/acs.jmedchem.8b00560] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Improper regulation of complement is associated with various pathologies, and the clinical demand for compounds that can regulate complement activation is therefore imperative. Cp40, an analog of the peptide compstatin, inhibits all complement pathways at the level of the central component C3. We have further developed Cp40, using either PEGylation at the N-terminus or insertion of charged amino acids at the C-terminus. The PEGylated analogs are highly soluble and retained their inhibitory activity, with C3b binding affinity dependent on the length of the PEG chain. The addition of two or three residues of lysine, in turn, not only improved the peptide's solubility but also increased the binding affinity for C3b while retaining its inhibitory potency. Three of the new derivatives showed improved pharmacokinetic profiles in vivo in non-human primates. Given their compelling solubility and pharmacokinetic profiles, these new Cp40 analogs should broaden the spectrum of administration routes, likely reducing dosing frequency during chronic treatment and potentially expanding their range of clinical application.
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Affiliation(s)
- Nadja Berger
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Tchilabalo Dilezitoko Alayi
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - Ranillo R G Resuello
- Simian Conservation Breeding and Research Center (SICONBREC) , Makati City 1231 , Philippines
| | - Joel V Tuplano
- Simian Conservation Breeding and Research Center (SICONBREC) , Makati City 1231 , Philippines
| | - Edimara S Reis
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine , University of Pennsylvania , Philadelphia , Pennsylvania 19104 , United States
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11
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De Benedetti PG, Fanelli F. Computational modeling approaches to quantitative structure-binding kinetics relationships in drug discovery. Drug Discov Today 2018; 23:1396-1406. [PMID: 29574212 DOI: 10.1016/j.drudis.2018.03.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 02/22/2018] [Accepted: 03/19/2018] [Indexed: 11/22/2022]
Abstract
Simple comparative correlation analyses and quantitative structure-kinetics relationship (QSKR) models highlight the interplay of kinetic rates and binding affinity as an essential feature in drug design and discovery. The choice of the molecular series, and their structural variations, used in QSKR modeling is fundamental to understanding the mechanistic implications of ligand and/or drug-target binding and/or unbinding processes. Here, we discuss the implications of linear correlations between kinetic rates and binding affinity constants and the relevance of the computational approaches to QSKR modeling.
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Affiliation(s)
- Pier G De Benedetti
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy.
| | - Francesca Fanelli
- Department of Life Sciences, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy; Center for Neuroscience and Neurotechnology, University of Modena and Reggio Emilia, via Campi 103, 41125 Modena, Italy
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12
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Olcina MM, Kim RK, Melemenidis S, Graves EE, Giaccia AJ. The tumour microenvironment links complement system dysregulation and hypoxic signalling. Br J Radiol 2018; 92:20180069. [PMID: 29544344 PMCID: PMC6435069 DOI: 10.1259/bjr.20180069] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The complement system is an innate immune pathway typically thought of as part of the first line of defence against “non-self” species. In the context of cancer, complement has been described to have an active role in facilitating cancer-associated processes such as increased proliferation, angiogenesis and migration. Several cellular members of the tumour microenvironment express and/or produce complement proteins locally, including tumour cells. Dysregulation of the complement system has been reported in numerous tumours and increased expression of complement activation fragments in cancer patient specimens correlates with poor patient prognosis. Importantly, genetic or pharmacological targeting of complement has been shown to reduce tumour growth in several cancer preclinical models, suggesting that complement could be an attractive therapeutic target. Hypoxia (low oxygen) is frequently found in solid tumours and has a profound biological impact on cellular and non-cellular components of the tumour microenvironment. In this review, we focus on hypoxia since this is a prevailing feature of the tumour microenvironment that, like increased complement, is typically associated with poor prognosis. Furthermore, interesting links between hypoxia and complement have been recently proposed but never collectively reviewed. Here, we explore how hypoxia alters regulation of complement proteins in different cellular components of the tumour microenvironment, as well as the downstream biological consequences of this regulation.
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Affiliation(s)
- Monica M Olcina
- Department of Radiation Oncology, Stanford University, Stanford, CA, USA
| | - Ryan K Kim
- Department of Radiation Oncology, Stanford University, Stanford, CA, USA
| | | | - Edward E Graves
- Department of Radiation Oncology, Stanford University, Stanford, CA, USA
| | - Amato J Giaccia
- Department of Radiation Oncology, Stanford University, Stanford, CA, USA
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13
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Abstract
INTRODUCTION Therapeutic modulation of complement activation is considered as a promising approach for the treatment of host tissue damage in several inflammatory and autoimmune diseases. Complement component protein C3 is a particularly attractive drug target for complement inhibitors, due to its central role in three pathways of complement activation cascade. Areas covered: The author provides a comprehensive review on compstatin family peptides which have been discovered and optimized as potent and selective C3 inhibitors via a combination of chemical, biophysical and computational approaches. New generations of the compstatin family with improved potency and therapeutic properties have been developed in recent years. Over two decades, compstatin demonstrated therapeutic potential as a first-of-its-kind complement inhibitor in a series of disease models, with encouraging efforts in clinical trials. Expert opinion: Compstatin holds promise for new therapeutic implications in blocking the effect of the complement cascade in a variety of disease conditions. The development of cost-effective treatment options with suitable dosing route and schedule will be critical for patients with complement mediated chronic diseases.
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Affiliation(s)
- Yijun Huang
- a WuXi AppTec Inc ., Philadelphia , PA , USA
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14
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Abstract
Paroxysmal nocturnal haemoglobinuria (PNH) is a clonal haematopoietic stem cell (HSC) disease that presents with haemolytic anaemia, thrombosis and smooth muscle dystonias, as well as bone marrow failure in some cases. PNH is caused by somatic mutations in PIGA (which encodes phosphatidylinositol N-acetylglucosaminyltransferase subunit A) in one or more HSC clones. The gene product of PIGA is required for the biosynthesis of glycosylphosphatidylinositol (GPI) anchors; thus, PIGA mutations lead to a deficiency of GPI-anchored proteins, such as complement decay-accelerating factor (also known as CD55) and CD59 glycoprotein (CD59), which are both complement inhibitors. Clinical manifestations of PNH occur when a HSC clone carrying somatic PIGA mutations acquires a growth advantage and differentiates, generating mature blood cells that are deficient of GPI-anchored proteins. The loss of CD55 and CD59 renders PNH erythrocytes susceptible to intravascular haemolysis, which can lead to thrombosis and to much of the morbidity and mortality of PNH. The accumulation of anaphylatoxins (such as C5a) from complement activation might also have a role. The natural history of PNH is highly variable, ranging from quiescent to life-threatening. Therapeutic strategies include terminal complement blockade and bone marrow transplantation. Eculizumab, a monoclonal antibody complement inhibitor, is highly effective and the only licensed therapy for PNH.
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Affiliation(s)
- Anita Hill
- Department of Haematology, St. James' University Hospital, Leeds, UK
| | - Amy E DeZern
- Division of Hematology, Johns Hopkins Department of Medicine, Johns Hopkins University, Ross Research Building, Room 1025, 720 Rutland Avenue, Baltimore, Maryland 21205, USA
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA
| | - Taroh Kinoshita
- Laboratory of Immunoglycobiology, Immunology Frontier Research Center, Osaka University, Osaka, Japan
- Department of Immunoregulation Research Institute for Microbial Diseases, Osaka University, Osaka, Japan
| | - Robert A Brodsky
- Division of Hematology, Johns Hopkins Department of Medicine, Johns Hopkins University, Ross Research Building, Room 1025, 720 Rutland Avenue, Baltimore, Maryland 21205, USA
- Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, Baltimore, Maryland, USA
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15
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Schuetz DA, de Witte WEA, Wong YC, Knasmueller B, Richter L, Kokh DB, Sadiq SK, Bosma R, Nederpelt I, Heitman LH, Segala E, Amaral M, Guo D, Andres D, Georgi V, Stoddart LA, Hill S, Cooke RM, De Graaf C, Leurs R, Frech M, Wade RC, de Lange ECM, IJzerman AP, Müller-Fahrnow A, Ecker GF. Kinetics for Drug Discovery: an industry-driven effort to target drug residence time. Drug Discov Today 2017; 22:896-911. [PMID: 28412474 DOI: 10.1016/j.drudis.2017.02.002] [Citation(s) in RCA: 132] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2016] [Revised: 01/24/2017] [Accepted: 02/17/2017] [Indexed: 01/05/2023]
Abstract
A considerable number of approved drugs show non-equilibrium binding characteristics, emphasizing the potential role of drug residence times for in vivo efficacy. Therefore, a detailed understanding of the kinetics of association and dissociation of a target-ligand complex might provide crucial insight into the molecular mechanism-of-action of a compound. This deeper understanding will help to improve decision making in drug discovery, thus leading to a better selection of interesting compounds to be profiled further. In this review, we highlight the contributions of the Kinetics for Drug Discovery (K4DD) Consortium, which targets major open questions related to binding kinetics in an industry-driven public-private partnership.
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Affiliation(s)
- Doris A Schuetz
- Department of Pharmaceutical Chemistry, University of Vienna, UZA 2, Althanstrasse 14, 1090 Vienna, Austria
| | | | - Yin Cheong Wong
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Bernhard Knasmueller
- Department of Pharmaceutical Chemistry, University of Vienna, UZA 2, Althanstrasse 14, 1090 Vienna, Austria
| | - Lars Richter
- Department of Pharmaceutical Chemistry, University of Vienna, UZA 2, Althanstrasse 14, 1090 Vienna, Austria
| | - Daria B Kokh
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloß-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - S Kashif Sadiq
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloß-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
| | - Reggie Bosma
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, P.O. Box 7161, 1007 MC Amsterdam, The Netherlands
| | - Indira Nederpelt
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, Leiden, Einsteinweg 55, Leiden, 2300RA, The Netherlands
| | - Laura H Heitman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, Leiden, Einsteinweg 55, Leiden, 2300RA, The Netherlands
| | - Elena Segala
- Heptares Therapeutics,Biopark, Broadwater Road, Welwyn Garden City, Hertfordshire, AL7 3AX, UK
| | - Marta Amaral
- Discovery Technologies, Merck KGaA, Frankfurter Straße 250, 64293 Darmstadt, Germany; Instituto de Biologia Experimental e Tecnológica, Avenida da República, Estação Agronómica Nacional, 2780-157 Oeiras, Portugal
| | - Dong Guo
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, Leiden, Einsteinweg 55, Leiden, 2300RA, The Netherlands
| | - Dorothee Andres
- Bayer AG, Drug Discovery, Pharmaceuticals, Lead Discovery Berlin, Müllerstr. 178, 13353 Berlin, Germany
| | - Victoria Georgi
- Bayer AG, Drug Discovery, Pharmaceuticals, Lead Discovery Berlin, Müllerstr. 178, 13353 Berlin, Germany
| | - Leigh A Stoddart
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Steve Hill
- School of Life Sciences, University of Nottingham, Nottingham, NG7 2UH, UK
| | - Robert M Cooke
- Heptares Therapeutics,Biopark, Broadwater Road, Welwyn Garden City, Hertfordshire, AL7 3AX, UK
| | - Chris De Graaf
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, P.O. Box 7161, 1007 MC Amsterdam, The Netherlands
| | - Rob Leurs
- Department of Chemistry and Pharmaceutical Sciences, Division of Medicinal Chemistry, Amsterdam Institute for Molecules, Medicines and Systems (AIMMS), Vrije Universiteit Amsterdam, P.O. Box 7161, 1007 MC Amsterdam, The Netherlands
| | - Matthias Frech
- Discovery Technologies, Merck KGaA, Frankfurter Straße 250, 64293 Darmstadt, Germany
| | - Rebecca C Wade
- Molecular and Cellular Modeling Group, Heidelberg Institute for Theoretical Studies (HITS), Schloß-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany; Zentrum für Molekulare Biologie der Universität Heidelberg, DKFZ-ZMBH Alliance, Im Neuenheimer Feld 280, 69120 Heidelberg, Germany; Interdisciplinary Center for Scientific Computing (IWR), Heidelberg University, Im Neuenheimer Feld 205, 69120 Heidelberg, Germany
| | - Elizabeth Cunera Maria de Lange
- Division of Pharmacology, Leiden Academic Centre for Drug Research, Leiden University, Einsteinweg 55, 2333 CC Leiden, The Netherlands
| | - Adriaan P IJzerman
- Division of Medicinal Chemistry, Leiden Academic Centre for Drug Research (LACDR), Leiden University, P.O. Box 9502, Leiden, Einsteinweg 55, Leiden, 2300RA, The Netherlands
| | - Anke Müller-Fahrnow
- Bayer AG, Drug Discovery, Pharmaceuticals, Lead Discovery Berlin, Müllerstr. 178, 13353 Berlin, Germany
| | - Gerhard F Ecker
- Department of Pharmaceutical Chemistry, University of Vienna, UZA 2, Althanstrasse 14, 1090 Vienna, Austria.
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16
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Ricklin D, Reis ES, Mastellos DC, Gros P, Lambris JD. Complement component C3 - The "Swiss Army Knife" of innate immunity and host defense. Immunol Rev 2016; 274:33-58. [PMID: 27782325 PMCID: PMC5427221 DOI: 10.1111/imr.12500] [Citation(s) in RCA: 273] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
As a preformed defense system, complement faces a delicate challenge in providing an immediate, forceful response to pathogens even at first encounter, while sparing host cells in the process. For this purpose, it engages a tightly regulated network of plasma proteins, cell surface receptors, and regulators. Complement component C3 plays a particularly versatile role in this process by keeping the cascade alert, acting as a point of convergence of activation pathways, fueling the amplification of the complement response, exerting direct effector functions, and helping to coordinate downstream immune responses. In recent years, it has become evident that nature engages the power of C3 not only to clear pathogens but also for a variety of homeostatic processes ranging from tissue regeneration and synapse pruning to clearing debris and controlling tumor cell progression. At the same time, its central position in immune surveillance makes C3 a target for microbial immune evasion and, if improperly engaged, a trigger point for various clinical conditions. In our review, we look at the versatile roles and evolutionary journey of C3, discuss new insights into the molecular basis for C3 function, provide examples of disease involvement, and summarize the emerging potential of C3 as a therapeutic target.
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Affiliation(s)
- Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
| | - Edimara S Reis
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Dimitrios C Mastellos
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA
- National Center for Scientific Research 'Demokritos', Athens, Greece
| | - Piet Gros
- Utrecht University, Utrecht, The Netherlands
| | - John D Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA, USA.
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17
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Risitano AM, Marotta S. Therapeutic complement inhibition in complement-mediated hemolytic anemias: Past, present and future. Semin Immunol 2016; 28:223-40. [PMID: 27346521 DOI: 10.1016/j.smim.2016.05.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2016] [Revised: 04/24/2016] [Accepted: 05/02/2016] [Indexed: 12/12/2022]
Abstract
The introduction in the clinic of anti-complement agents represented a major achievement which gave to physicians a novel etiologic treatment for different human diseases. Indeed, the first anti-complement agent eculizumab has changed the treatment paradigm of paroxysmal nocturnal hemoglobinuria (PNH), dramatically impacting its severe clinical course. In addition, eculizumab is the first agent approved for atypical Hemolytic Uremic Syndrome (aHUS), a life-threatening inherited thrombotic microangiopathy. Nevertheless, such remarkable milestone in medicine has brought to the fore additional challenges for the scientific community. Indeed, the list of complement-mediated anemias is not limited to PNH and aHUS, and other human diseases can be considered for anti-complement treatment. They include other thrombotic microangiopathies, as well as some antibody-mediated hemolytic anemias. Furthermore, more than ten years of experience with eculizumab led to a better understanding of the individual steps of the complement cascade involved in the pathophysiology of different human diseases. Based on this, new unmet clinical needs are emerging; a number of different strategies are currently under development to improve current anti-complement treatment, trying to address these specific clinical needs. They include: (i) alternative anti-C5 agents, which may improve the heaviness of eculizumab treatment; (ii) broad-spectrum anti-C3 agents, which may improve the efficacy of anti-C5 treatment by intercepting the complement cascade upstream (i.e., preventing C3-mediated extravascular hemolysis in PNH); (iii) targeted inhibitors of selective complement activating pathways, which may prevent early pathogenic events of specific human diseases (e.g., anti-classical pathway for antibody-mediated anemias, or anti-alternative pathway for PNH and aHUS). Here we briefly summarize the status of art of current and future complement inhibition for different complement-mediated anemias, trying to identify the most promising approaches for each individual disease.
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Affiliation(s)
- Antonio M Risitano
- Hematology, Department of Clinical Medicine and Surgery; Federico II University, Naples, Italy.
| | - Serena Marotta
- Hematology, Department of Clinical Medicine and Surgery; Federico II University, Naples, Italy
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18
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Schoop A, Dey F. On-rate based optimization of structure-kinetic relationship--surfing the kinetic map. DRUG DISCOVERY TODAY. TECHNOLOGIES 2015; 17:9-15. [PMID: 26724331 DOI: 10.1016/j.ddtec.2015.08.003] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2015] [Accepted: 08/24/2015] [Indexed: 05/16/2023]
Abstract
In the lead discovery process residence time has become an important parameter for the identification and characterization of the most efficacious compounds in vivo. To enable the success of compound optimization by medicinal chemistry toward a desired residence time the understanding of structure-kinetic relationship (SKR) is essential. This article reviews various approaches to monitor SKR and suggests using the on-rate as the key monitoring parameter. The literature is reviewed and examples of compound series with low variability as well as with significant changes in on-rates are highlighted. Furthermore, findings of kinetic on-rate changes are presented and potential underlying rationales are discussed.
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Affiliation(s)
- Andreas Schoop
- Proteros biostructures GmbH, Bunsenstrasse 7a, 82152 Martinsried, Germany.
| | - Fabian Dey
- Roche Pharmaceutical Research and Early Development, Small Molecule Research, Roche Innovation Center Basel, Grenzacherstrasse 124, 4070 Basel, Switzerland
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19
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Vauquelin G, Huber W, Swinney DC. Experimental Methods to Determine Binding Kinetics. THERMODYNAMICS AND KINETICS OF DRUG BINDING 2015. [DOI: 10.1002/9783527673025.ch9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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20
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Risitano AM. Complement inhibition for paroxysmal nocturnal hemoglobinuria: where we stand and where we are going. Expert Opin Orphan Drugs 2015. [DOI: 10.1517/21678707.2015.1041376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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21
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Risitano AM. Current and Future Pharmacologic Complement Inhibitors. Hematol Oncol Clin North Am 2015; 29:561-82. [DOI: 10.1016/j.hoc.2015.01.009] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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22
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Design strategies to address kinetics of drug binding and residence time. Bioorg Med Chem Lett 2015; 25:2019-27. [DOI: 10.1016/j.bmcl.2015.02.027] [Citation(s) in RCA: 64] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2014] [Revised: 02/06/2015] [Accepted: 02/11/2015] [Indexed: 02/06/2023]
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23
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Vanderpool D, Grimshaw CE, Lawson JD, Ermolieff J. Residence time and kinetic efficiency analysis of extracellular signal-regulated kinase 2 inhibitors. Anal Biochem 2015; 473:46-52. [DOI: 10.1016/j.ab.2014.12.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 02/02/2023]
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24
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Gorham R, Forest DL, Khoury GA, Smadbeck J, Beecher CN, Healy ED, Tamamis P, Archontis G, Larive C, Floudas CA, Radeke MJ, Johnson LV, Morikis D. New compstatin peptides containing N-terminal extensions and non-natural amino acids exhibit potent complement inhibition and improved solubility characteristics. J Med Chem 2015; 58:814-26. [PMID: 25494040 PMCID: PMC4306506 DOI: 10.1021/jm501345y] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Indexed: 01/21/2023]
Abstract
Compstatin peptides are complement inhibitors that bind and inhibit cleavage of complement C3. Peptide binding is enhanced by hydrophobic interactions; however, poor solubility promotes aggregation in aqueous environments. We have designed new compstatin peptides derived from the W4A9 sequence (Ac-ICVWQDWGAHRCT-NH2, cyclized between C2 and C12), based on structural, computational, and experimental studies. Furthermore, we developed and utilized a computational framework for the design of peptides containing non-natural amino acids. These new compstatin peptides contain polar N-terminal extensions and non-natural amino acid substitutions at positions 4 and 9. Peptides with α-modified non-natural alanine analogs at position 9, as well as peptides containing only N-terminal polar extensions, exhibited similar activity compared to W4A9, as quantified via ELISA, hemolytic, and cell-based assays, and showed improved solubility, as measured by UV absorbance and reverse-phase HPLC experiments. Because of their potency and solubility, these peptides are promising candidates for therapeutic development in numerous complement-mediated diseases.
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Affiliation(s)
- Ronald
D. Gorham
- Department
of Bioengineering, University of California, Riverside, California 92521, United States
| | - David L. Forest
- Center
for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, California 93106, United States
| | - George A. Khoury
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - James Smadbeck
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Consuelo N. Beecher
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Evangeline D. Healy
- Center
for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, California 93106, United States
| | - Phanourios Tamamis
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
- Department
of Physics, University of Cyprus, PO20537, CY1678 Nicosia, Cyprus
| | - Georgios Archontis
- Department
of Physics, University of Cyprus, PO20537, CY1678 Nicosia, Cyprus
| | - Cynthia
K. Larive
- Department
of Chemistry, University of California, Riverside, California 92521, United States
| | - Christodoulos A. Floudas
- Department
of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Monte J. Radeke
- Center
for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, California 93106, United States
| | - Lincoln V. Johnson
- Center
for the Study of Macular Degeneration, Neuroscience Research Institute, University of California, Santa Barbara, California 93106, United States
| | - Dimitrios Morikis
- Department
of Bioengineering, University of California, Riverside, California 92521, United States
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25
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Khoury GA, Smadbeck J, Tamamis P, Vandris AC, Kieslich CA, Floudas CA. Forcefield_NCAA: ab initio charge parameters to aid in the discovery and design of therapeutic proteins and peptides with unnatural amino acids and their application to complement inhibitors of the compstatin family. ACS Synth Biol 2014; 3:855-69. [PMID: 24932669 PMCID: PMC4277759 DOI: 10.1021/sb400168u] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
We describe the development and testing of ab initio derived, AMBER ff03 compatible charge parameters for a large library of 147 noncanonical amino acids including β- and N-methylated amino acids for use in applications such as protein structure prediction and de novo protein design. The charge parameter derivation was performed using the RESP fitting approach. Studies were performed assessing the suitability of the derived charge parameters in discriminating the activity/inactivity between 63 analogs of the complement inhibitor Compstatin on the basis of previously published experimental IC50 data and a screening procedure involving short simulations and binding free energy calculations. We found that both the approximate binding affinity (K*) and the binding free energy calculated through MM-GBSA are capable of discriminating between active and inactive Compstatin analogs, with MM-GBSA performing significantly better. Key interactions between the most potent Compstatin analog that contains a noncanonical amino acid are presented and compared to the most potent analog containing only natural amino acids and native Compstatin. We make the derived parameters and an associated web interface that is capable of performing modifications on proteins using Forcefield_NCAA and outputting AMBER-ready topology and parameter files freely available for academic use at http://selene.princeton.edu/FFNCAA . The forcefield allows one to incorporate these customized amino acids into design applications with control over size, van der Waals, and electrostatic interactions.
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Affiliation(s)
- George A. Khoury
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - James Smadbeck
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Phanourios Tamamis
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Andrew C. Vandris
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Chris A. Kieslich
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
| | - Christodoulos A. Floudas
- Department of Chemical and Biological Engineering, Princeton University, Princeton, New Jersey 08544, United States
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26
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Alonso JA, Andrés M, Bravo M, Buil MA, Calbet M, Castro J, Eastwood PR, Esteve C, Ferrer M, Forns P, Gómez E, González J, Lozoya E, Mir M, Moreno I, Petit S, Roberts RS, Sevilla S, Vidal B, Vidal L, Vilaseca P. Structure-activity relationships (SAR) and structure-kinetic relationships (SKR) of bicyclic heteroaromatic acetic acids as potent CRTh2 antagonists III: the role of a hydrogen-bond acceptor in long receptor residence times. Bioorg Med Chem Lett 2014; 24:5127-33. [PMID: 25437506 DOI: 10.1016/j.bmcl.2014.08.028] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 08/07/2014] [Accepted: 08/08/2014] [Indexed: 12/23/2022]
Abstract
The correct positioning and orientation of an hydrogen bond acceptor (HBA) in the tail portion of the biaryl series of CRTh2 antagonists is a requirement for long receptor residence time. The HBA in combination with a small steric substituent in the core section (R(core) ≠ H) gives access to compounds with dissociation half-lives of ⩾ 24h.
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Affiliation(s)
- Juan Antonio Alonso
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Miriam Andrés
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Mónica Bravo
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Maria Antonia Buil
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Marta Calbet
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Jordi Castro
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Paul R Eastwood
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Cristina Esteve
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Manel Ferrer
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Pilar Forns
- Almirall-Barcelona Science Park Unit, Barcelona Science Park, Josep Samitier 1-5, 08028 Barcelona, Spain
| | - Elena Gómez
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Jacob González
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Estrella Lozoya
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Marta Mir
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Imma Moreno
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Silvia Petit
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Richard S Roberts
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain.
| | - Sara Sevilla
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Bernat Vidal
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Laura Vidal
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
| | - Pere Vilaseca
- Almirall R&D Centre, Laureano Miró, 408-410, 08980 Sant Feliu de Llobregat, Barcelona, Spain
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27
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Huang Y, Reis ES, Knerr PJ, van der Donk WA, Ricklin D, Lambris JD. Conjugation to albumin-binding molecule tags as a strategy to improve both efficacy and pharmacokinetic properties of the complement inhibitor compstatin. ChemMedChem 2014; 9:2223-6. [PMID: 25056114 DOI: 10.1002/cmdc.201402212] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Indexed: 01/20/2023]
Abstract
The compstatin family of complement inhibitors has shown promise in various immuno-inflammatory disorders. Although recent analogues show beneficial pharmacokinetics, further extension of the plasma half-life is expected to benefit systemic application of these peptidic inhibitors. We therefore synthesized conjugates of compstatin analogues and albumin-binding molecules (ABM) to increase circulatory residence. Equilibrium dialysis in complement-depleted serum showed a marked increase in plasma protein binding from <8 % to >99 % for a resulting chimera (ABM2-Cp20). Further analysis confirmed interaction with albumin from different species, primarily via site II. Importantly, ABM2-Cp20 bound 20-fold stronger to its target protein C3b (KD =150 pM) than the parent peptide. Kinetic and in silico analysis suggested that ABM2 occupies a secondary site on C3b and improves the dissociation rate via additional contacts. Addition of an ABM modifier thereby not only improved plasma protein binding but also produced the most potent compstatin analogue to date with potential implications for the treatment of systemic complement-related diseases.
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Affiliation(s)
- Yijun Huang
- Department of Pathology and Laboratory Medicine, Perelman School of Medicine, University of Pennsylvania, 401 Stellar-Chance Laboratories, Philadelphia, PA 19104 (USA)
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28
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Peptide inhibitors of C3 activation as a novel strategy of complement inhibition for the treatment of paroxysmal nocturnal hemoglobinuria. Blood 2014; 123:2094-101. [PMID: 24497537 DOI: 10.1182/blood-2013-11-536573] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Paroxysmal nocturnal hemoglobinuria (PNH) is characterized by complement-mediated intravascular hemolysis due to the lack of CD55 and CD59 on affected erythrocytes. The anti-C5 antibody eculizumab has proven clinically effective, but uncontrolled C3 activation due to CD55 absence may result in opsonization of erythrocytes, possibly leading to clinically meaningful extravascular hemolysis. We investigated the effect of the peptidic C3 inhibitor, compstatin Cp40, and its long-acting form (polyethylene glycol [PEG]-Cp40) on hemolysis and opsonization of PNH erythrocytes in an established in vitro system. Both compounds demonstrated dose-dependent inhibition of hemolysis with IC50 ∼4 µM and full inhibition at 6 µM. Protective levels of either Cp40 or PEG-Cp40 also efficiently prevented deposition of C3 fragments on PNH erythrocytes. We further explored the potential of both inhibitors for systemic administration and performed pharmacokinetic evaluation in nonhuman primates. A single intravenous injection of PEG-Cp40 resulted in a prolonged elimination half-life of >5 days but may potentially affect the plasma levels of C3. Despite faster elimination kinetics, saturating inhibitor concentration could be reached with unmodified Cp40 through repetitive subcutaneous administration. In conclusion, peptide inhibitors of C3 activation effectively prevent hemolysis and C3 opsonization of PNH erythrocytes, and are excellent, and potentially cost-effective, candidates for further clinical investigation.
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29
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Gorham RD, Forest DL, Tamamis P, López de Victoria A, Kraszni M, Kieslich CA, Banna CD, Bellows-Peterson ML, Larive CK, Floudas CA, Archontis G, Johnson LV, Morikis D. Novel compstatin family peptides inhibit complement activation by drusen-like deposits in human retinal pigmented epithelial cell cultures. Exp Eye Res 2013; 116:96-108. [PMID: 23954241 DOI: 10.1016/j.exer.2013.07.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 07/06/2013] [Accepted: 07/20/2013] [Indexed: 11/19/2022]
Abstract
We have used a novel human retinal pigmented epithelial (RPE) cell-based model that mimics drusen biogenesis and the pathobiology of age-related macular degeneration to evaluate the efficacy of newly designed peptide inhibitors of the complement system. The peptides belong to the compstatin family and, compared to existing compstatin analogs, have been optimized to promote binding to their target, complement protein C3, and to enhance solubility by improving their polarity/hydrophobicity ratios. Based on analysis of molecular dynamics simulation data of peptide-C3 complexes, novel binding features were designed by introducing intermolecular salt bridge-forming arginines at the N-terminus and at position -1 of N-terminal dipeptide extensions. Our study demonstrates that the RPE cell assay has discriminatory capability for measuring the efficacy and potency of inhibitory peptides in a macular disease environment.
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Affiliation(s)
- Ronald D Gorham
- Department of Bioengineering, University of California, Riverside, CA 92521, USA
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30
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Qu H, Ricklin D, Bai H, Chen H, Reis ES, Maciejewski M, Tzekou A, DeAngelis RA, Resuello RRG, Lupu F, Barlow PN, Lambris JD. New analogs of the clinical complement inhibitor compstatin with subnanomolar affinity and enhanced pharmacokinetic properties. Immunobiology 2013; 218:496-505. [PMID: 22795972 PMCID: PMC3518557 DOI: 10.1016/j.imbio.2012.06.003] [Citation(s) in RCA: 95] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 06/12/2012] [Indexed: 02/04/2023]
Abstract
Therapeutic modulation of the complement system has become increasingly important in line with the growing recognition of the role of complement in numerous diseases. Compstatin, a peptidic inhibitor that acts at the central level of the complement cascade, is currently in clinical evaluation but routes to improve its efficacy have not yet been fully explored. Here, we report improvements in both the inhibitory potency and pharmacokinetic parameters of compstatin that broaden its clinical applications. Selective modification of the compstatin N-terminus with non-proteinogenic amino acids resulted in the first analogue with subnanomolar binding affinity (KD=0.5nM) and other similarly potent derivatives with improved solubility in clinically relevant solvents. Detailed structure-activity relationship studies based on biophysical and computational methods revealed key structural determinants for the observed improvements. Importantly, pharmacokinetic evaluation in non-human primates revealed target-driven elimination kinetics with plasma half-life values exceeding expectations for peptidic drugs (close to 12h). This successful optimization strategy is expected to pave the way for systemic administration of compstatin in a range of clinical conditions.
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Affiliation(s)
- Hongchang Qu
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Hongjun Bai
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Hui Chen
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Edimara S. Reis
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Mateusz Maciejewski
- School of Chemistry and School of Biological Sciences, University of Edinburgh, United Kingdom
| | - Apostolia Tzekou
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | - Robert A. DeAngelis
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
| | | | - Florea Lupu
- Cardiovascular Biology Research Program, Oklahoma Medical Research Foundation, USA
| | - Paul N. Barlow
- School of Chemistry and School of Biological Sciences, University of Edinburgh, United Kingdom
| | - John D. Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, USA
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Ricklin D. Manipulating the mediator: modulation of the alternative complement pathway C3 convertase in health, disease and therapy. Immunobiology 2013; 217:1057-66. [PMID: 22964231 DOI: 10.1016/j.imbio.2012.07.016] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2012] [Revised: 07/17/2012] [Accepted: 07/17/2012] [Indexed: 10/27/2022]
Abstract
The complement network is increasingly recognized as an important triage system that is able to differentiate between healthy host cells, microbial intruders, cellular debris and immune complexes, and tailor its actions accordingly. At the center of this triage mechanism is the alternative pathway C3 convertase (C3bBb), a potent enzymatic protein complex capable of rapidly converting the inert yet abundant component C3 into powerful effector fragments (C3a and C3b), thereby amplifying the initial response on unprotected surfaces and inducing a variety of effector functions. A fascinating molecular mechanism of convertase assembly and intrinsic regulation, as well as the interplay with a panel of cell surface-bound and soluble inhibitors are essential for directing complement attack to intruders and protecting healthy host cells. While efficiently keeping immune surveillance and homeostasis on track, the reliance on an intricate cascade of interaction and conversion steps also renders the C3 convertase vulnerable to derail. On the one hand, tissue damage, accumulation of debris, or polymorphisms in complement genes may unfavorably shift the balance between activation and regulation, thereby contributing to a variety of clinical conditions. On the other hand, pathogens developed powerful evasion strategies to avoid complement attack by targeting the convertase. Finally, we increasingly challenge our bodies with foreign materials such as biomaterial implants or drug delivery vehicles that may induce adverse effects that are at least partially caused by complement activation and amplification via the alternative pathway. The involvement of the C3 convertase in a range of pathological conditions put this complex into the spotlight of complement-targeted drug discovery efforts. Fortunately, the physiological regulation and microbial evasion approaches provide a rich source of inspiration for the development of powerful treatment options. This review provides insight into the current knowledge about the molecular mechanisms that drive C3 convertase activity, reveals common and divergent strategies of convertase inhibition employed by host and pathogens, and how this inhibitory arsenal can be tapped for developing therapeutic options to treat complement-related diseases.
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Affiliation(s)
- Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia 19104, USA.
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32
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Targeted complement inhibition as a promising strategy for preventing inflammatory complications in hemodialysis. Immunobiology 2013; 217:1097-105. [PMID: 22964235 DOI: 10.1016/j.imbio.2012.07.012] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 07/17/2012] [Indexed: 01/10/2023]
Abstract
Hemodialysis is the most common method used to remove waste and hazardous products of metabolism in patients suffering from renal failure. Hundreds of thousands of people with end-stage renal disease undergo hemodialysis treatment in the United States each year. Strikingly, the 5-year survival rate for all dialysis patients is only 35%. Most of the patients succumb to cardiovascular disease that is exacerbated by the chronic induction of inflammation caused by contact of the blood with the dialysis membrane. The complement system, a strong mediator of pro-inflammatory networks, is a key contributor to such biomaterial-induced inflammation. Though only evaluated in experimental ex vivo settings, specific targeting of complement activation during hemodialysis has uncovered valuable information that points toward the therapeutic use of complement inhibitors as a means to control the unwelcomed inflammatory responses and consequent pathologies in hemodialysis patients.
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33
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Holdgate G, Geschwindner S, Breeze A, Davies G, Colclough N, Temesi D, Ward L. Biophysical methods in drug discovery from small molecule to pharmaceutical. Methods Mol Biol 2013; 1008:327-355. [PMID: 23729258 DOI: 10.1007/978-1-62703-398-5_12] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Biophysical methods have become established in many areas of drug discovery. Application of these methods was once restricted to a relatively small number of scientists using specialized, low throughput technologies and methods. Now, automated high-throughput instruments are to be found in a growing number of laboratories. Many biophysical methods are capable of measuring the equilibrium binding constants between pairs of molecules crucial for molecular recognition processes, encompassing protein-protein, protein-small molecule, and protein-nucleic acid interactions, and several can be used to measure the kinetic or thermodynamic components controlling these biological processes. For a full characterization of a binding process, determinations of stoichiometry, binding mode, and any conformational changes associated with such interactions are also required. The suite of biophysical methods that are now available represents a powerful toolbox of techniques which can effectively deliver this full characterization.The aim of this chapter is to provide the reader with an overview of the drug discovery process and how biophysical methods, such as surface plasmon resonance (SPR), isothermal titration calorimetry (ITC), nuclear magnetic resonance, mass spectrometry (MS), and thermal unfolding methods can answer specific questions in order to influence project progression and outcomes. The selection of these examples is based upon the experiences of the authors at AstraZeneca, and relevant approaches are highlighted where they have utility in a particular drug discovery scenario.
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Abstract
The complement cascade is a major contributor to the innate immune response. It has now been well accepted that complement plays a critical role in hyperacute rejection and acute antibody-mediated rejection of transplanted organ. There is also increasing evidence that complement proteins contribute to the pathogenesis of organ ischemia-reperfusion injury, and even to cell-mediated rejection. Furthermore, the chemoattractants C3a and C5a and the terminal membrane attack complex that are generated by complement activation can directly or indirectly mediate tissue injury and trigger adaptive immune responses. Here, we review recent findings concerning the role of complement in graft ischemia-reperfusion injury, antibody-mediated rejection and accommodation, and cell-mediated rejection. We also discuss the current status of complement intervention therapies in clinical transplantation and describe potential new therapeutic strategies for clinical application.
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Affiliation(s)
- Gang Chen
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
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35
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Harboe M, Garred P, Lindstad JK, Pharo A, Müller F, Stahl GL, Lambris JD, Mollnes TE. The role of properdin in zymosan- and Escherichia coli-induced complement activation. THE JOURNAL OF IMMUNOLOGY 2012; 189:2606-13. [PMID: 22851705 DOI: 10.4049/jimmunol.1200269] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Properdin is well known as an enhancer of the alternative complement amplification loop when C3 is activated, whereas its role as a recognition molecule of exogenous pathogen-associated molecular patterns and initiator of complement activation is less understood. We therefore studied the role of properdin in activation of complement in normal human serum by zymosan and various Escherichia coli strains. In ELISA, microtiter plates coated with zymosan induced efficient complement activation with deposition of C4b and terminal complement complex on the solid phase. Virtually no deposition of C4b or terminal complement complex was observed with mannose-binding lectin (MBL)-deficient serum. Reconstitution with purified MBL showed distinct activation in both readouts. In ELISA, normal human serum-induced deposition of properdin by zymosan was abolished by the C3-inhibiting peptide compstatin. Flow cytometry was used to further explore whether properdin acts as an initial recognition molecule reacting directly with zymosan and three E. coli strains. Experiments reported by other authors were made with EGTA Mg²⁺ buffer, permitting autoactivation of C3. We found inhibition by compstatin on these substrates, indicating that properdin deposition depended on initial C3b deposition followed by properdin in a second step. Properdin released from human polymorphonuclear cells stimulated with PMA did not bind to zymosan or E. coli, but when incubated in properdin-depleted serum this form of properdin bound efficiently to both substrates in a strictly C3-dependent manner, as the binding was abolished by compstatin. Collectively, these data indicate that properdin in serum as well as polymorphonuclear-released properdin is unable to bind and initiate direct alternative pathway activation on these substrates.
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Affiliation(s)
- Morten Harboe
- Institute of Immunology, University of Oslo and Oslo University Hospital, Rikshospitalet, NO-0027 Oslo, Norway
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36
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Rich RL, Myszka DG. Survey of the 2009 commercial optical biosensor literature. J Mol Recognit 2012; 24:892-914. [PMID: 22038797 DOI: 10.1002/jmr.1138] [Citation(s) in RCA: 83] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We took a different approach to reviewing the commercial biosensor literature this year by inviting 22 biosensor users to serve as a review committee. They set the criteria for what to expect in a publication and ultimately decided to use a pass/fail system for selecting which papers to include in this year's reference list. Of the 1514 publications in 2009 that reported using commercially available optical biosensor technology, only 20% passed their cutoff. The most common criticism the reviewers had with the literature was that "the biosensor experiments could have been done better." They selected 10 papers to highlight good experimental technique, data presentation, and unique applications of the technology. This communal review process was educational for everyone involved and one we will not soon forget.
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Affiliation(s)
- Rebecca L Rich
- Center for Biomolecular Interaction Analysis, University of Utah, Salt Lake City, UT, USA
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37
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Target–drug interactions: first principles and their application to drug discovery. Drug Discov Today 2012; 17:10-22. [DOI: 10.1016/j.drudis.2011.06.013] [Citation(s) in RCA: 126] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Revised: 06/07/2011] [Accepted: 06/28/2011] [Indexed: 02/06/2023]
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38
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Knerr PJ, Tzekou A, Ricklin D, Qu H, Chen H, van der Donk WA, Lambris JD. Synthesis and activity of thioether-containing analogues of the complement inhibitor compstatin. ACS Chem Biol 2011; 6:753-60. [PMID: 21520911 DOI: 10.1021/cb2000378] [Citation(s) in RCA: 66] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Disulfide bonds are essential for the structural stability and biological activity of many bioactive peptides. However, these bonds are labile to reducing agents, which can limit the therapeutic utility of such peptides. Substitution of a disulfide bond with a reduction-resistant cystathionine bridge is an attractive means of improving stability while imposing minimal structural perturbation to the peptide. We have applied this approach to the therapeutic complement inhibitor compstatin, a disulfide-containing peptide currently in clinical trials for age-related macular degeneration, in an effort to maintain its potent activity while improving its biological stability. Thioether-containing compstatin analogues were produced via solid-phase peptide synthesis utilizing orthogonally protected cystathionine amino acid building blocks and solid-supported peptide cyclization. Overall, the affinity of these analogues for their biological target and potent inhibition of complement activation were largely maintained when compared to those of the parent disulfide-containing peptides. Thus, the improved stability to reduction conferred by the thioether bond makes this new class of compstatin peptides a promising alternative for therapeutic applications. Additionally, the versatility of this synthesis allows for exploration of disulfide-to-thioether substitution in a variety of other therapeutic peptides.
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Affiliation(s)
| | - Apostolia Tzekou
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Daniel Ricklin
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Hongchang Qu
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | - Hui Chen
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
| | | | - John D. Lambris
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104, United States
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39
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López de Victoria A, Gorham RD, Bellows-Peterson ML, Ling J, Lo DD, Floudas CA, Morikis D. A new generation of potent complement inhibitors of the Compstatin family. Chem Biol Drug Des 2011; 77:431-40. [PMID: 21352502 DOI: 10.1111/j.1747-0285.2011.01111.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Compstatin family peptides are potent inhibitors of the complement system and promising drug candidates against diseases involving under-regulated complement activation. Compstatin is a 13-residue cyclized peptide that inhibits cleavage of complement protein C3, preventing downstream complement activation. We present three new compstatin variants, characterized by tryptophan replacement at positions 1 and/or 13. Peptide design was based on physicochemical reasoning and was inspired by earlier work, which identified tryptophan substitutions at positions 1 and 13 in peptides with predicted C3c binding abilities [Bellows M.L., Fung H.K., Taylor M.S., Floudas C.A., López de Victoria A., Morikis D. (2010) Biophys J; 98: 2337-2346]. The new variants preserve distinct polar and nonpolar surfaces of compstatin, but have altered local interaction capabilities with C3. All three peptides exhibited potent C3 binding by surface plasmon resonance and potent complement inhibition by enzyme-linked immunosorbent assay. We also present enzyme-linked immunosorbent assay data and detailed surface plasmon resonance kinetic data of three peptides from previous computational design.
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Affiliation(s)
- Aliana López de Victoria
- Department of Bioengineering and Center for Bioengineering Research, University of California, Riverside, CA 92521, USA
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40
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Abstract
Complement is a part of the body's innate immune system that helps defend the host from microbial infection. It is tightly controlled by a number of cell surface and fluid-phase proteins so that under normal circumstances injury to autologous tissues is avoided. In many pathological settings, such as when the complement regulatory mechanisms are dysfunctional or overwhelmed, complement attack of autologous tissues can occur with severe, sometimes life-threatening consequences. The kidney appears to be particularly vulnerable to complement-mediated inflammatory injury and many kidney pathologies have been linked to abnormal complement activation. Clinical and experimental studies have shown that complement attack can be a primary cause in rare, genetically predisposed kidney diseases or a significant contributor to kidney injury caused by other etiological factors. Here we provide a brief review of recent advances on the activation and regulation of the complement system in kidney disease, with a particular emphasis on the relevance of complement regulatory proteins.
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Affiliation(s)
- Allison M Lesher
- Institute for Translational Medicine and Therapeutics and Department of Pharmacology, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
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41
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Qu H, Magotti P, Ricklin D, Wu EL, Kourtzelis I, Wu YQ, Kaznessis YN, Lambris JD. Novel analogues of the therapeutic complement inhibitor compstatin with significantly improved affinity and potency. Mol Immunol 2010; 48:481-9. [PMID: 21067811 DOI: 10.1016/j.molimm.2010.10.004] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Accepted: 10/10/2010] [Indexed: 11/26/2022]
Abstract
Compstatin is a 13-residue disulfide-bridged peptide that inhibits a key step in the activation of the human complement system. Compstatin and its derivatives have shown great promise for the treatment of many clinical disorders associated with unbalanced complement activity. To obtain more potent compstatin analogues, we have now performed an N-methylation scan of the peptide backbone and amino acid substitutions at position 13. One analogue (Ac-I[CVW(Me)QDW-Sar-AHRC](NMe)I-NH(2)) displayed a 1000-fold increase in both potency (IC(50) = 62 nM) and binding affinity for C3b (K(D) = 2.3 nM) over that of the original compstatin. Biophysical analysis using surface plasmon resonance and isothermal titration calorimetry suggests that the improved binding originates from more favorable free conformation and stronger hydrophobic interactions. This study provides a series of significantly improved drug leads for therapeutic applications in complement-related diseases, and offers new insights into the structure-activity relationships of compstatin analogues.
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Affiliation(s)
- Hongchang Qu
- Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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42
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Tamamis P, Morikis D, Floudas CA, Archontis G. Species specificity of the complement inhibitor compstatin investigated by all-atom molecular dynamics simulations. Proteins 2010; 78:2655-67. [PMID: 20589629 PMCID: PMC3138065 DOI: 10.1002/prot.22780] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The development of compounds to regulate the activation of the complement system in non-primate species is of profound interest because it can provide models for human diseases. The peptide compstatin inhibits protein C3 in primate mammals and is a potential therapeutic agent against unregulated activation of complement in humans but is inactive against nonprimate species. Here, we elucidate this species specificity of compstatin by molecular dynamics simulations of complexes between the most potent natural compstatin analog and human or rat C3. The results are compared against an experimental conformation of the human complex, determined recently by X-ray diffraction at 2.4-A resolution. The human complex simulations provide information on the relative contributions to stability of specific C3 and compstatin residues. In the rat simulations, the protein undergoes reproducible conformational changes, which eliminate or weaken specific interactions and reduce the complex stability. The simulation insights can be used to design improved compstatin-based inhibitors for human C3 and active inhibitors against lower mammals.
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Affiliation(s)
- Phanourios Tamamis
- Department of Physics, University of Cyprus, PO20537, Nicosia CY1678, Cyprus
| | - Dimitrios Morikis
- Department of Bioengineering, University of California, Riverside, California 92521
| | | | - Georgios Archontis
- Department of Physics, University of Cyprus, PO20537, Nicosia CY1678, Cyprus
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43
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Qu H, Ricklin D, Lambris JD. Recent developments in low molecular weight complement inhibitors. Mol Immunol 2009; 47:185-95. [PMID: 19800693 DOI: 10.1016/j.molimm.2009.08.032] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2009] [Accepted: 08/28/2009] [Indexed: 11/18/2022]
Abstract
As a key part of the innate immune system, complement plays an important role not only in defending against invading pathogens but also in many other biological processes. Inappropriate or excessive activation of complement has been linked to many autoimmune, inflammatory, and neurodegenerative diseases, as well as ischemia-reperfusion injury and cancer. A wide array of low molecular weight complement inhibitors has been developed to target various components of the complement cascade. Their efficacy has been demonstrated in numerous in vitro and in vivo experiments. Though none of these inhibitors has reached the market so far, some of them have entered clinical trials and displayed promising results. This review provides a brief overview of the currently developed low molecular weight complement inhibitors, including short peptides and synthetic small molecules, with an emphasis on those targeting components C1 and C3, and the anaphylatoxin receptors.
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Affiliation(s)
- Hongchang Qu
- Department of Pathology and Laboratory Medicine, School of Medicine, University of Pennsylvania, 401 Stellar Chance, 422 Curie Blvd., Philadelphia, PA 19104, USA
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