1
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Cremosnik G, Mesrouze Y, Zueger P, Furkert D, Grandjean F, Argoti D, Mermet-Meillon F, Bauer MR, Brittain S, Rogemoser P, Yang W, Giovannoni J, McGregor L, Tang J, Knapp M, Holzinger S, Buhr S, Muller L, Leder L, Xie L, Fernandez C, Nieto-Oberhuber C, Chène P, Galli GG, Sesterhenn F. mRNA Display Identifies Potent, Paralog-Selective Peptidic Ligands for ARID1B. ACS Chem Biol 2024; 19:1142-1150. [PMID: 38655884 PMCID: PMC11106749 DOI: 10.1021/acschembio.4c00083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2024] [Revised: 04/15/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024]
Abstract
The ARID1A and ARID1B subunits are mutually exclusive components of the BAF variant of SWI/SNF chromatin remodeling complexes. Loss of function mutations in ARID1A are frequently observed in various cancers, resulting in a dependency on the paralog ARID1B for cancer cell proliferation. However, ARID1B has never been targeted directly, and the high degree of sequence similarity to ARID1A poses a challenge for the development of selective binders. In this study, we used mRNA display to identify peptidic ligands that bind with nanomolar affinities to ARID1B and showed high selectivity over ARID1A. Using orthogonal biochemical, biophysical, and chemical biology tools, we demonstrate that the peptides engage two different binding pockets, one of which directly involves an ARID1B-exclusive cysteine that could allow covalent targeting by small molecules. Our findings impart the first evidence of the ligandability of ARID1B, provide valuable tools for drug discovery, and suggest opportunities for the development of selective molecules to exploit the synthetic lethal relationship between ARID1A and ARID1B in cancer.
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Affiliation(s)
- Gregor
S. Cremosnik
- Global
Discovery Chemistry, Novartis Biomedical
Research, CH-4056 Basel, Switzerland
| | - Yannick Mesrouze
- Disease
area Oncology, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Patrik Zueger
- Global
Discovery Chemistry, Novartis Biomedical
Research, CH-4056 Basel, Switzerland
| | - David Furkert
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Frédéric Grandjean
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Dayana Argoti
- Global
Discovery Chemistry, Novartis Biomedical
Research, Emeryville, California 94608, United States
| | | | - Matthias R. Bauer
- Global
Discovery Chemistry, Novartis Biomedical
Research, CH-4056 Basel, Switzerland
| | - Scott Brittain
- Discovery
Sciences, Novartis Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Phuong Rogemoser
- Discovery
Sciences, Novartis Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Winnie Yang
- Discovery
Sciences, Novartis Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Jerome Giovannoni
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Lynn McGregor
- Discovery
Sciences, Novartis Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Jenny Tang
- Global
Discovery Chemistry, Novartis Biomedical
Research, Emeryville, California 94608, United States
| | - Mark Knapp
- Global
Discovery Chemistry, Novartis Biomedical
Research, Emeryville, California 94608, United States
| | - Sandra Holzinger
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Sylvia Buhr
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Lionel Muller
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Lukas Leder
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Lili Xie
- Discovery
Sciences, Novartis Biomedical Research, Emeryville, California 94608, United States
| | - Cesar Fernandez
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | | | - Patrick Chène
- Disease
area Oncology, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Giorgio G. Galli
- Disease
area Oncology, Novartis Biomedical Research, CH-4056 Basel, Switzerland
| | - Fabian Sesterhenn
- Discovery
Sciences, Novartis Biomedical Research, CH-4056 Basel, Switzerland
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2
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Thomas JR, Shelton C, Murphy J, Brittain S, Bray MA, Aspesi P, Concannon J, King FJ, Ihry RJ, Ho DJ, Henault M, Hadjikyriacou A, Neri M, Sigoillot FD, Pham HT, Shum M, Barys L, Jones MD, Martin EJ, Blechschmidt A, Rieffel S, Troxler TJ, Mapa FA, Jenkins JL, Jain RK, Kutchukian PS, Schirle M, Renner S. Enhancing the Small-Scale Screenable Biological Space beyond Known Chemogenomics Libraries with Gray Chemical Matter─Compounds with Novel Mechanisms from High-Throughput Screening Profiles. ACS Chem Biol 2024; 19:938-952. [PMID: 38565185 PMCID: PMC11040606 DOI: 10.1021/acschembio.3c00737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 02/28/2024] [Accepted: 03/01/2024] [Indexed: 04/04/2024]
Abstract
Phenotypic assays have become an established approach to drug discovery. Greater disease relevance is often achieved through cellular models with increased complexity and more detailed readouts, such as gene expression or advanced imaging. However, the intricate nature and cost of these assays impose limitations on their screening capacity, often restricting screens to well-characterized small compound sets such as chemogenomics libraries. Here, we outline a cheminformatics approach to identify a small set of compounds with likely novel mechanisms of action (MoAs), expanding the MoA search space for throughput limited phenotypic assays. Our approach is based on mining existing large-scale, phenotypic high-throughput screening (HTS) data. It enables the identification of chemotypes that exhibit selectivity across multiple cell-based assays, which are characterized by persistent and broad structure activity relationships (SAR). We validate the effectiveness of our approach in broad cellular profiling assays (Cell Painting, DRUG-seq, and Promotor Signature Profiling) and chemical proteomics experiments. These experiments revealed that the compounds behave similarly to known chemogenetic libraries, but with a notable bias toward novel protein targets. To foster collaboration and advance research in this area, we have curated a public set of such compounds based on the PubChem BioAssay dataset and made it available for use by the scientific community.
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Affiliation(s)
- Jason R. Thomas
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Claude Shelton
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Jason Murphy
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Scott Brittain
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Mark-Anthony Bray
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Peter Aspesi
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - John Concannon
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Frederick J. King
- Novartis
Biomedical Research, San Diego, California 92121, United States
| | - Robert J. Ihry
- Novartis
Biomedical Research, San Diego, California 92121, United States
| | - Daniel J. Ho
- Novartis
Biomedical Research, San Diego, California 92121, United States
| | - Martin Henault
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | | | - Marilisa Neri
- Novartis
Biomedical Research, Basel 4056, Switzerland
| | | | - Helen T. Pham
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Matthew Shum
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Louise Barys
- Novartis
Biomedical Research, Basel 4056, Switzerland
| | - Michael D. Jones
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Eric J. Martin
- Novartis
Biomedical Research, Emeryville, California 94608, United States
| | | | | | | | - Felipa A. Mapa
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Jeremy L. Jenkins
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | - Rishi K. Jain
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
| | | | - Markus Schirle
- Novartis
Biomedical Research, Cambridge, Massachusetts 02139, United States
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3
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Spyker DA, Dart RC, Yip L, Reynolds K, Brittain S, Yarema M. Population pharmacokinetic analysis of acetaminophen overdose with immediate release, extended release and modified release formulations. Clin Toxicol (Phila) 2022; 60:1113-1121. [PMID: 36106921 DOI: 10.1080/15563650.2022.2114361] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
OBJECTIVES The introduction of delayed release formulations of acetaminophen (APAP) has created concern about the role of formulation in overdose. We examined the APAP overdose pharmacokinetic (PK) profiles to assess the role of dose, coingestants and formulation: immediate release (IR), extended release (ER), and modified release (MR) on APAP pharmacokinetic measures. METHODS We collected by-subject APAP PK data: subject description, timed blood APAP concentrations, dose, and coingestants. We sought both overdose and randomized controlled trials (RCTs) for supratherapeutic doses involving ER or MR formulations. Data analysis and simulation used the non-linear mixed-effects modeling program NONMEM-version 7.4. RESULTS The final dataset comprised 3,033 [APAP] from 356 subjects and 15 sources including 3 RCTs (179 subjects receiving IR, 122 ER, 65 MR). The final population PK (PopPK) model was a linear 2-compartment model with first-order (oral) absorption. Covariate relationships included: APAP absorption rate and bioavailability decreased with increased oral dose (p < 0.00005) for all 3 formulations (MR > ER > IR). Post hoc analyses showed opioid coingestant increased exposure (area under the curve, AUC) by factor of 1.6. Simulations of 100 g vs 10 g doses for IR, ER and MR showed overdose of the ER formulation exhibits slower absorption and lower Cmax, overall exposure (AUC) is less than 80% of an equivalent dose of IR acetaminophen. The overall exposure for the MR formulation is less than 70% of an equivalent dose of IR. CONCLUSIONS Acetaminophen ER and MR formulations have slower absorption and decreased bioavailability leading to a lower Cmax and later Tmax than the IR formulation. These results have potential clinical implications because delayed absorption could confound use of the Rumack-Matthew nomogram by underestimating the severity of ingestion early in the course of treatment.
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Affiliation(s)
| | | | - Luke Yip
- Rocky Mountain Poison and Drug Center, Denver, CO, USA
| | - Kate Reynolds
- Rocky Mountain Poison and Drug Center, Denver, CO, USA
| | | | - Mark Yarema
- Poison and Drug Information Service, Calgary, Alberta, CA, USA
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4
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Griebel G, Pichat P, Beeské S, Leroy T, Redon N, Jacquet A, Françon D, Bert L, Even L, Lopez-Grancha M, Tolstykh T, Sun F, Yu Q, Brittain S, Arlt H, He T, Zhang B, Wiederschain D, Bertrand T, Houtmann J, Rak A, Vallée F, Michot N, Augé F, Menet V, Bergis OE, George P, Avenet P, Mikol V, Didier M, Escoubet J. Selective blockade of the hydrolysis of the endocannabinoid 2-arachidonoylglycerol impairs learning and memory performance while producing antinociceptive activity in rodents. Sci Rep 2015; 5:7642. [PMID: 25560837 PMCID: PMC4284516 DOI: 10.1038/srep07642] [Citation(s) in RCA: 88] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2014] [Accepted: 12/03/2014] [Indexed: 12/27/2022] Open
Abstract
Monoacylglycerol lipase (MAGL) represents a primary degradation enzyme of the endogenous cannabinoid (eCB), 2-arachidonoyglycerol (2-AG). This study reports a potent covalent MAGL inhibitor, SAR127303. The compound behaves as a selective and competitive inhibitor of mouse and human MAGL, which potently elevates hippocampal levels of 2-AG in mice. In vivo, SAR127303 produces antinociceptive effects in assays of inflammatory and visceral pain. In addition, the drug alters learning performance in several assays related to episodic, working and spatial memory. Moreover, long term potentiation (LTP) of CA1 synaptic transmission and acetylcholine release in the hippocampus, two hallmarks of memory function, are both decreased by SAR127303. Although inactive in acute seizure tests, repeated administration of SAR127303 delays the acquisition and decreases kindled seizures in mice, indicating that the drug slows down epileptogenesis, a finding deserving further investigation to evaluate the potential of MAGL inhibitors as antiepileptics. However, the observation that 2-AG hydrolysis blockade alters learning and memory performance, suggests that such drugs may have limited value as therapeutic agents.
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Affiliation(s)
- Guy Griebel
- Sanofi R&D, Exploratory Unit, Chilly-Mazarin, France
| | | | - Sandra Beeské
- Sanofi R&D, Exploratory Unit, Chilly-Mazarin, France
| | - Thibaud Leroy
- Sanofi R&D, Exploratory Unit, Chilly-Mazarin, France
| | - Nicolas Redon
- Sanofi R&D, Exploratory Unit, Chilly-Mazarin, France
| | - Agnès Jacquet
- Sanofi R&D, Exploratory Unit, Chilly-Mazarin, France
| | | | | | - Luc Even
- Sanofi R&D, Exploratory Unit, Chilly-Mazarin, France
| | | | | | | | - Qunyan Yu
- Global Oncology Division, Cambridge, USA
| | | | - Heike Arlt
- Global Oncology Division, Cambridge, USA
| | - Timothy He
- Global Oncology Division, Cambridge, USA
| | | | | | - Thomas Bertrand
- Lead Generation To Candidate Realization, Vitry-sur-Seine, France
| | - Jacques Houtmann
- Lead Generation To Candidate Realization, Vitry-sur-Seine, France
| | - Alexey Rak
- Lead Generation To Candidate Realization, Vitry-sur-Seine, France
| | - François Vallée
- Lead Generation To Candidate Realization, Vitry-sur-Seine, France
| | - Nadine Michot
- Lead Generation To Candidate Realization, Vitry-sur-Seine, France
| | - Franck Augé
- Sanofi R&D, Exploratory Unit, Chilly-Mazarin, France
| | | | | | - Pascal George
- Therapeutic Strategic Unit Aging, Chilly-Mazarin, France
| | | | - Vincent Mikol
- Lead Generation To Candidate Realization, Vitry-sur-Seine, France
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5
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Baroldi P, Brittain S, Louro D, Johnson J. Efficacy and Tolerability of SPN-804, a Novel, Once-Daily Extended-Release Formulation of Oxcarbazepine as Adjunctive Therapy in Patients with Refractory Partial Seizures (P06.101). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p06.101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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6
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Johnson J, Brittain S, Keeler E, Louro D, Baroldi P. Oxcarbazepine Extended-Release (SPN-804) Therapy in Patients with Refractory Partial Seizures: Review of Neurologic and Ophthalmologic Adverse Events (P06.107). Neurology 2012. [DOI: 10.1212/wnl.78.1_meetingabstracts.p06.107] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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7
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Kimchi-Sarfaty C, Brittain S, Garfield S, Caplen NJ, Tang Q, Gottesman MM. Efficient Delivery of RNA Interference Effectors via In Vitro-Packaged SV40 Pseudovirions. Hum Gene Ther 2005. [DOI: 10.1089/hum.2005.16.ft-110] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
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8
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Kimchi-Sarfaty C, Alexander NS, Brittain S, Ali S, Gottesman MM. Transduction of multiple cell types using improved conditions for gene delivery and expression of SV40 pseudovirions packaged in vitro. Biotechniques 2004; 37:270-5. [PMID: 15335219 DOI: 10.2144/04372rr04] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
This comprehensive study demonstrates highly efficient transduction of a wide variety of human, murine, and monkey cell lines, using a procedure for in vitro packaging of plasmid DNA in recombinant simian virus 40 (SV40) capsid proteins to form pseudovirions. The pseudovirions are encapsidated by the VP1 major capsid protein, with no SV40 sequence requirement, and are able to carry up to 17.7 kb of supercoiled plasmid DNA. We developed a procedure to scale-up production of SV40 pseudovirions, as well as an efficient protocol to concentrate the virions with no loss of activity. We also developed a method that allows transduction of 10 times more cells than the original protocol. This protocol was tested using supercoiled in vitro-packaged plasmid carrying the human multidrug-resistance gene (MDR1 encoding P-glycoprotein; P-gp), or the enhanced green fluorescent protein reporter gene (EGFP) in .45 human lymphoblastoid cells and in K562 human erythroleukemia cells. Multiple transductions at 24-h intervals were shown to increase expression using the EGFP reporter gene. The protocols developed in this study establish in vitro-packaged SV40 pseudovirions as one of the most efficient gene delivery systems.
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9
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Li R, Carmichael WW, Brittain S, Eaglesham GK, Shaw GR, Mahakhant A, Noparatnaraporn N, Yongmanitchai W, Kaya K, Watanabe MM. Isolation and identification of the cyanotoxin cylindrospermopsin and deoxy-cylindrospermopsin from a Thailand strain of Cylindrospermopsis raciborskii (Cyanobacteria). Toxicon 2001; 39:973-80. [PMID: 11223086 DOI: 10.1016/s0041-0101(00)00236-1] [Citation(s) in RCA: 148] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
A strain of Cylindrospermopsis (Cyanobacteria) isolated from a fishpond in Thailand was examined for its taxonomy based upon morphology and 16S rRNA gene sequence. It was also examined for production of the hepatotoxic cyanotoxin called cylindrospermopsin (CYN) and deoxycylindrospermopsin (deoxy-CYN). The strain (CY-Thai) was identified as C. raciborskii (Woloszynska) Seenaya and Subba Raju based upon morphological examination which was confirmed by 16S rRNA gene sequences and phylogenetic comparisons based upon its 16S rRNA gene. The alkaloid heptatotoxin CYN was confirmed using mouse bioassay, HPLC and HPLC-MS/MS while deoxy-CYN was confirmed using HPLC-MS/MS. The mouse bioassay gave a minimum lethal dose at 250mg dry weight cells/kg body weight within 24h and 125mg/kg at 72h, with signs of poisoning the same as in literature reports for CYN. HPLC chromatographic comparison of the CY-Thai toxin with standard CYN gave the same retention time and an absorbance maximum at 262nm. HPLC-MS/MS confirmed the presence of CYN (M+H 416) and deoxy-CYN (M+H 400). The CYN content in strain CY-Thai was estimated at 1.02mg/g and approximately 1/10 of this amount for deoxy-CYN. This is the first report from Asia of a CYN, deoxy-CYN producing Cylindrospermopsis raciborskii.
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Affiliation(s)
- R Li
- Department of Biological Sciences, Wright State University, Dayton, OH 45435, USA
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10
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Mumma MJ, Dello Russo N, DiSanti MA, Magee-Sauer K, Novak RE, Brittain S, Rettig T, McLean IS, Reuter DC, Xu LH. Organic Composition of C/1999 S4 (LINEAR): A Comet Formed Near Jupiter? Science 2001; 292:1334-9. [PMID: 11359002 DOI: 10.1126/science.1058929] [Citation(s) in RCA: 128] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
In the current paradigm, Oort cloud comets formed in the giant planets' region of the solar nebula, where temperatures and other conditions varied greatly. The measured compositions of four such comets (Halley, Hyakutake, Hale-Bopp, and Lee) are consistent with formation from interstellar ices in the cold nebular region beyond Uranus. The composition of comet C/1999 S4 (LINEAR) differs greatly, which suggests that its ices condensed from processed nebular gas, probably in the Jupiter-Saturn region. Its unusual organic composition may require reevaluation of the prebiotic organic material delivered to the young Earth by comets.
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Affiliation(s)
- M J Mumma
- Laboratory for Extraterrestrial Physics, Code 690, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
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11
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Wu H, Brittain S, Anderson J, Grzybowski B, Whitesides S, Whitesides GM. Fabrication of Topologically Complex Three-Dimensional Microstructures: Metallic Microknots. J Am Chem Soc 2000. [DOI: 10.1021/ja002687t] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Hongkai Wu
- Contribution from the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and School of Computer Science, McGill University, 3480 University Street #318, Montreal, Quebec H3A 2A7, Canada
| | - Scott Brittain
- Contribution from the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and School of Computer Science, McGill University, 3480 University Street #318, Montreal, Quebec H3A 2A7, Canada
| | - Janelle Anderson
- Contribution from the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and School of Computer Science, McGill University, 3480 University Street #318, Montreal, Quebec H3A 2A7, Canada
| | - Bartosz Grzybowski
- Contribution from the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and School of Computer Science, McGill University, 3480 University Street #318, Montreal, Quebec H3A 2A7, Canada
| | - Sue Whitesides
- Contribution from the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and School of Computer Science, McGill University, 3480 University Street #318, Montreal, Quebec H3A 2A7, Canada
| | - George M. Whitesides
- Contribution from the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138, and School of Computer Science, McGill University, 3480 University Street #318, Montreal, Quebec H3A 2A7, Canada
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12
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Brittain S, Mohamed ZA, Wang J, Lehmann VK, Carmichael WW, Rinehart KL. Isolation and characterization of microcystins from a river nile strain of Oscillatoria tenuis Agardh ex Gomont. Toxicon 2000; 38:1759-71. [PMID: 10858515 DOI: 10.1016/s0041-0101(00)00105-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
The River Nile is the major source of drinking water in Egypt, however, increased eutrophication due to agricultural, municipal and industrial runoff has contributed to the growth of toxin producing cyanobacteria. This study describes the isolation and characterization of microcystins (MCYSTs), cyclic heptapeptide hepatotoxins, from a rare strain of Oscillatoria tenuis, isolated from the River Nile at Sohag province in July 1995. The MCYST concentration of laboratory-cultured O. tenuis strain E6 was found to be 0.3 mg/g freeze-dried weight determined by enzyme-linked immunosorbent assay (ELISA). Two microcystins, 1 and 2, were isolated from lyophilized cells using solid phase extraction and reversed-phase high performance liquid chromatography (HPLC). Structures were assigned based upon their amino acid analyses, electrospray ionization mass spectrometry (ESIMS, ESIMS-CID-MS), high resolution fast atom bombardment mass spectrometry, and nuclear magnetic resonance data ((1)H and (1)H COSY NMR). Toxin 1 was identified as MCYST-LR, and toxin 2, a new MCYST, as MCYST-LHArg ([L-homoarginine(4)]). Previous studies indicate that Oscillatoria agardhii strains produce demethylated MCYSTs (containing D-Asp and/or dehydroalanine). This is the first report of a toxic O. tenuis, strain E6, one which produces a fully methylated MCYST, MCYST-LR and a new L-homoarginine containing MCYST, MCYST-LHArg.
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Affiliation(s)
- S Brittain
- Department of Biological Sciences, Wright State University, Dayton, OH 45435, USA
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13
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Bowden N, Brittain S, Evans AG, Hutchinson JW, Whitesides GM. Spontaneous formation of ordered structures in thin films of metals supported on an elastomeric polymer. Nature 1998. [DOI: 10.1038/30193] [Citation(s) in RCA: 1872] [Impact Index Per Article: 72.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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14
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Namikoshi M, Yuan M, Sivonen K, Carmichael WW, Rinehart KL, Rouhiainen L, Sun F, Brittain S, Otsuki A. Seven new microcystins possessing two L-glutamic acid units, isolated from Anabaena sp. strain 186. Chem Res Toxicol 1998; 11:143-9. [PMID: 9511906 DOI: 10.1021/tx970120t] [Citation(s) in RCA: 47] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Electrospray ionization mass spectrometry has been applied to the structure assignment of seven new microcystins (1-7), obtained from cultured Anabaena sp. strain 186. The seven new microcystins contain the dehydroalanine (Dha) or L-Ser unit instead of the N-methyldehydroalanine unit and the L-Glu and/or its delta-methyl ester [E(OMe)] units at the two variable L-amino acid units, and the structures were assigned as [Dha7]microcystin-E(OMe)E(OMe) (1), [D-Asp3,Dha7]microcystin-E(OMe)E(OMe) (2), [L-Ser7]microcystin-E(OMe)E(OMe) (3), [D-Asp3,L-Ser7]microcystin-E(OMe)E(OMe) (4), [Dha7]microcystin-EE(OMe) (5), [D-Asp3,Dha7]microcystin-EE(OMe) (6), and [L-Ser7]microcystin-EE(OMe) (7). These microcystins are the first examples containing dicarboxylic amino acids at the two variable L-amino acid units in microcystins.
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Affiliation(s)
- M Namikoshi
- Department of Ocean Sciences, Tokyo University of Fisheries, Japan.
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