1
|
Bierlich KC, Kane A, Hildebrand L, Bird CN, Fernandez Ajo A, Stewart JD, Hewitt J, Hildebrand I, Sumich J, Torres LG. Downsized: gray whales using an alternative foraging ground have smaller morphology. Biol Lett 2023; 19:20230043. [PMID: 37554011 PMCID: PMC10410206 DOI: 10.1098/rsbl.2023.0043] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Accepted: 07/20/2023] [Indexed: 08/10/2023] Open
Abstract
Describing individual morphology and growth is key for identifying ecological niches and monitoring the health and fitness of populations. Eastern North Pacific ((ENP), approximately 16 650 individuals) gray whales primarily feed in the Arctic/sub-Arctic regions, while a small subgroup called the Pacific Coast Feeding Group (PCFG, approximately 212 individuals) instead feeds between northern California, USA and British Columbia, Canada. Evidence suggests PCFG whales have lower body condition than ENP whales. Here we investigate morphological differences (length, skull, and fluke span) and compare length-at-age growth curves between ENP and PCFG whales. We use ENP gray whale length-at-age data comprised of strandings, whaling, and aerial photogrammetry (1926-1997) for comparison to data from PCFG whales collected through non-invasive techniques (2016-2022) to estimate age (photo identification) and length (drone-based photogrammetry). We use Bayesian methods to incorporate uncertainty associated with morphological measurements (manual and photogrammetric) and age estimates. We find that while PCFG and ENP whales have similar growth rates, PCFG whales reach smaller asymptotic lengths. Additionally, PCFG whales have relatively smaller skulls and flukes than ENP whales. These findings represent a striking example of morphological adaptation that may facilitate PCFG whales accessing a foraging niche distinct from the Arctic foraging grounds of the broader ENP population.
Collapse
Affiliation(s)
- K. C. Bierlich
- Geospatial Ecology of Marine Megafauna Lab, Oregon State University, Corvallis, Oregon, USA
| | - A. Kane
- Geospatial Ecology of Marine Megafauna Lab, Oregon State University, Corvallis, Oregon, USA
| | - L. Hildebrand
- Geospatial Ecology of Marine Megafauna Lab, Oregon State University, Corvallis, Oregon, USA
| | - C. N. Bird
- Geospatial Ecology of Marine Megafauna Lab, Oregon State University, Corvallis, Oregon, USA
| | - A. Fernandez Ajo
- Geospatial Ecology of Marine Megafauna Lab, Oregon State University, Corvallis, Oregon, USA
| | - J. D. Stewart
- Ocean Ecology Lab, Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Corvallis, Oregon, USA
| | - J. Hewitt
- Department of Statistical Science, Duke University, Durham, NC, USA
| | - I. Hildebrand
- Geospatial Ecology of Marine Megafauna Lab, Oregon State University, Corvallis, Oregon, USA
| | - J. Sumich
- Marine Mammal Institute, Department of Fisheries, Wildlife and Conservation Sciences, Oregon State University, Corvallis, Oregon, USA
| | - L. G. Torres
- Geospatial Ecology of Marine Megafauna Lab, Oregon State University, Corvallis, Oregon, USA
| |
Collapse
|
2
|
Stewart JD, Shakya KM, Bilinski T, Wilson JW, Ravi S, Choi CS. Variation of near surface atmosphere microbial communities at an urban and a suburban site in Philadelphia, PA, USA. Sci Total Environ 2020; 724:138353. [PMID: 32408469 DOI: 10.1016/j.scitotenv.2020.138353] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/02/2020] [Revised: 03/28/2020] [Accepted: 03/30/2020] [Indexed: 06/11/2023]
Abstract
Microorganisms are abundant in the near surface atmosphere and make up a significant fraction of organic aerosols with implications on both human health and ecosystem services. Despite their importance, studies investigating biogeographical patterns of the atmospheric microbiome between urban and suburban areas are limited. Urban and suburban locations (including their microbial communities) vary considerably depending on climate, topography, industrial activities, demographics and other socio-economic factors. Hence, we need more location-specific data to make informed decision affecting air quality, human health, and the implication of a changing climate and policy decisions. The objective of this study was to describe how the atmospheric microbiome varies in composition and function between urban and suburban sites. We used high-throughput sequencing to analyze microbial communities collected at different times from PM2.5 samples collected by active sampling method (using a pump and an impactor) and dust settling of TSP collected by passive sampling method (no pump and no impactor) from an urban and suburban site. We found diverse communities unique in composition at both sites with equivalent functional potential. Taxonomic composition varied significantly with Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes, and Other phyla in greater relative abundance at the urban site. In contrast, Cyanobacteria, Tenericutes, Fusobacteria, and Deinococcus, were enriched at the suburban site. Community diversity also demonstrated a high degree of temporal variation within site. We identified over one-third of the communities as potentially pathogenic taxa (urban: 47.52% ± 14.40%, suburban: 34.53% ± 14.60%) and determined the majority of organisms come from animal-associated host or are environmental non-specific. Potentially pathogenic taxa and source environments were similar between active- and passive- sampling method results. Our research is novel it adds to the underrepresented set of studies on atmospheric microbial structure and function across land types and is the first to compare suburban and urban atmospheric communities.
Collapse
Affiliation(s)
- J D Stewart
- Department of Geography & the Environment, Villanova University, PA, USA
| | - K M Shakya
- Department of Geography & the Environment, Villanova University, PA, USA.
| | - T Bilinski
- Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA
| | - J W Wilson
- Department of Biology, Villanova University, PA, USA
| | - S Ravi
- Department of Earth & Environmental Science, Temple University, PA, USA
| | - Chong Seok Choi
- Department of Earth & Environmental Science, Temple University, PA, USA
| |
Collapse
|
3
|
de Las Fuentes L, Sung YJ, Sitlani CM, Avery CL, Bartz TM, Keyser CD, Evans DS, Li X, Musani SK, Ruiter R, Smith AV, Sun F, Trompet S, Xu H, Arnett DK, Bis JC, Broeckel U, Busch EL, Chen YDI, Correa A, Cummings SR, Floyd JS, Ford I, Guo X, Harris TB, Ikram MA, Lange L, Launer LJ, Reiner AP, Schwander K, Smith NL, Sotoodehnia N, Stewart JD, Stott DJ, Stürmer T, Taylor KD, Uitterlinden A, Vasan RS, Wiggins KL, Cupples LA, Gudnason V, Heckbert SR, Jukema JW, Liu Y, Psaty BM, Rao DC, Rotter JI, Stricker B, Wilson JG, Whitsel EA. Genome-wide meta-analysis of variant-by-diuretic interactions as modulators of lipid traits in persons of European and African ancestry. Pharmacogenomics J 2019; 20:482-493. [PMID: 31806883 PMCID: PMC7260079 DOI: 10.1038/s41397-019-0132-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2019] [Revised: 11/13/2019] [Accepted: 11/20/2019] [Indexed: 01/11/2023]
Abstract
Hypertension (HTN) is a significant risk factor for cardiovascular morbidity and mortality. Metabolic abnormalities, including adverse cholesterol and triglycerides (TG) profiles, are frequent comorbid findings with HTN and contribute to cardiovascular disease. Diuretics, which are used to treat HTN and heart failure, have been associated with worsening of fasting lipid concentrations. Genome-wide meta-analyses with 39,710 European-ancestry (EA) individuals and 9,925 African-ancestry (AA) individuals were performed to identify genetic variants that modify the effect of loop or thiazide diuretic use on blood lipid concentrations. Both longitudinal and cross-sectional data were used to compute cohort-specific interaction results, which were then combined through meta-analysis in each ancestry. These ancestry-specific results were further combined through trans-ancestry meta-analysis. Analysis of EA data identified two genome-wide significant (p < 5×10−8) loci with single nucleotide variant (SNV)-loop diuretic interaction on TG concentrations (including COL11A1). Analysis of AA data identified one genome-wide significant locus adjacent to BMP2 with SNV-loop diuretic interaction on TG concentrations. Trans-ancestry analysis strengthened evidence of association for SNV-loop diuretic interaction at two loci (KIAA1217 and BAALC). There were few significant SNV-thiazide diuretic interaction associations on TG concentrations and for either diuretic on cholesterol concentrations. Several promising loci were identified that may implicate biologic pathways that contribute to adverse metabolic side effects from diuretic therapy.
Collapse
Affiliation(s)
- L de Las Fuentes
- Cardiovascular Division, Department of Medicine, Washington University, St. Louis, MO, USA.
| | - Y J Sung
- Division of Biostatistics, Washington University, St. Louis, MO, USA
| | - C M Sitlani
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - C L Avery
- Gillings School of Global Public Health, Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - T M Bartz
- Cardiovascular Health Research Unit, Departments of Medicine and Biostatistics, University of Washington, Seattle, WA, USA
| | - C de Keyser
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - D S Evans
- Research Institute, California Pacific Medical Center, San Francisco, CA, USA
| | - X Li
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - S K Musani
- Jackson Heart Study, Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - R Ruiter
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - A V Smith
- Icelandic Heart Association, Kopavogur, Iceland.,Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - F Sun
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - S Trompet
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.,Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - H Xu
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - D K Arnett
- Dean's Office, University of Kentucky College of Public Health, Lexington, KY, USA
| | - J C Bis
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - U Broeckel
- Section of Genomic Pediatrics, Department of Pediatrics, Medicine and Physiology, Medical College of Wisconsin, Milwaukee, WI, USA
| | - E L Busch
- Channing Division of Network Medicine, Department of Medicine, Harvard Medical School and Brigham and Women's Hospital, Boston, MA, USA.,Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Y-D I Chen
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - A Correa
- Jackson Heart Study, Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - S R Cummings
- Research Institute, California Pacific Medical Center, San Francisco, CA, USA
| | - J S Floyd
- Cardiovascular Health Research Unit, Departments of Medicine and Epidemiology, University of Washington, Seattle, WA, USA
| | - I Ford
- Robertson Center for biostatistics, University of Glasgow, Glasgow, UK
| | - X Guo
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - T B Harris
- Laboratory of Epidemiology and Population Sciences, Intramural Research Program, National Institute on Aging, Bethesda, MD, USA
| | - M A Ikram
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - L Lange
- Department of Genetics, University of Colorado, Denver, Denver, CO, USA
| | - L J Launer
- Laboratory of Epidemiology and Population Sciences, Intramural Research Program, National Institute on Aging, Bethesda, MD, USA
| | - A P Reiner
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA.,School of Public Health, Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - K Schwander
- Division of Biostatistics, Washington University, St. Louis, MO, USA
| | - N L Smith
- Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Seattle, WA, USA.,Seattle Epidemiologic Research and Information Center (ERIC), VA Cooperative Studies Program, VA Puget Sound Health Care System, Seattle, WA, USA
| | - N Sotoodehnia
- Cardiovascular Health Research Unit, Departments of Medicine and Epidemiology, University of Washington, Seattle, WA, USA.,Cardiology, Department of Medicine, University of Washington, Seattle, WA, USA
| | - J D Stewart
- Gillings School of Global Public Health, Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.,Carolina Population Center, University of North Carolina, Chapel Hill, NC, USA
| | - D J Stott
- Institute of cardiovascular and medical sciences, Faculty of Medicine, University of Glasgow, Glasgow, United Kingdom
| | - T Stürmer
- Gillings School of Global Public Health, Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.,Center for Pharmacoepidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - K D Taylor
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - A Uitterlinden
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - R S Vasan
- The Framingham Heart Study, Framingham, MA, USA.,Department of Medicine, Boston University School of Medicine, Boston, MA, USA
| | - K L Wiggins
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - L A Cupples
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA.,The Framingham Heart Study, Framingham, MA, USA
| | - V Gudnason
- Icelandic Heart Association, Kopavogur, Iceland.,Faculty of Medicine, University of Iceland, Reykjavik, Iceland
| | - S R Heckbert
- Cardiovascular Health Research Unit, Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - J W Jukema
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands.,Interuniversity Cardiology Institute of the Netherlands, Utrecht, The Netherlands
| | - Y Liu
- Division of Public Health Sciences, Department of Epidemiology and Prevention, Wake Forest University, Winston-, Salem, NC, USA
| | - B M Psaty
- Cardiovascular Health Research Unit, Departments of Epidemiology, Medicine, and Health Services, University of Washington, Seattle, WA, USA.,Kaiser Permanente Washington Health Research Institute, Seattle, WA, USA
| | - D C Rao
- Division of Biostatistics, Washington University, St. Louis, MO, USA
| | - J I Rotter
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - B Stricker
- Department of Epidemiology, Erasmus Medical Center, Rotterdam, The Netherlands
| | - J G Wilson
- Biophysics and Physiology, Department of Medicine, University of Mississippi Medical Center, Jackson, MS, USA
| | - E A Whitsel
- Gillings School of Global Public Health, Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA.,School of Medicine, Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
| |
Collapse
|
4
|
Seyerle AA, Sitlani CM, Noordam R, Gogarten SM, Li J, Li X, Evans DS, Sun F, Laaksonen MA, Isaacs A, Kristiansson K, Highland HM, Stewart JD, Harris TB, Trompet S, Bis JC, Peloso GM, Brody JA, Broer L, Busch EL, Duan Q, Stilp AM, O'Donnell CJ, Macfarlane PW, Floyd JS, Kors JA, Lin HJ, Li-Gao R, Sofer T, Méndez-Giráldez R, Cummings SR, Heckbert SR, Hofman A, Ford I, Li Y, Launer LJ, Porthan K, Newton-Cheh C, Napier MD, Kerr KF, Reiner AP, Rice KM, Roach J, Buckley BM, Soliman EZ, de Mutsert R, Sotoodehnia N, Uitterlinden AG, North KE, Lee CR, Gudnason V, Stürmer T, Rosendaal FR, Taylor KD, Wiggins KL, Wilson JG, Chen YD, Kaplan RC, Wilhelmsen K, Cupples LA, Salomaa V, van Duijn C, Jukema JW, Liu Y, Mook-Kanamori DO, Lange LA, Vasan RS, Smith AV, Stricker BH, Laurie CC, Rotter JI, Whitsel EA, Psaty BM, Avery CL. Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology. Pharmacogenomics J 2018; 18:215-226. [PMID: 28719597 PMCID: PMC5773415 DOI: 10.1038/tpj.2017.10] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 01/14/2017] [Accepted: 03/09/2017] [Indexed: 12/23/2022]
Abstract
Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.
Collapse
Affiliation(s)
- A A Seyerle
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Division of Epidemiology and Community Health, University of Minnesota, Minneapolis, MN, USA
| | - C M Sitlani
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - R Noordam
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
| | - S M Gogarten
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - J Li
- Department of Medicine, Division of Cardiovascular Medicine, Stanford University School of Medicine, Palo Alto, CA, USA
| | - X Li
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - D S Evans
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - F Sun
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - M A Laaksonen
- Department of Health, THL-National Institute for Health and Welfare, Helsinki, Finland
| | - A Isaacs
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
- CARIM School of Cardiovascular Diseases, Maastricht Centre for Systems Biology (MaCSBio), and Department of Biochemistry, Maastricht University, Maastricht, The Netherlands
| | - K Kristiansson
- Department of Health, THL-National Institute for Health and Welfare, Helsinki, Finland
| | - H M Highland
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - J D Stewart
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Carolina Population Center, University of North Carolina, Chapel Hill, NC, USA
| | - T B Harris
- Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, MD, USA
| | - S Trompet
- Department of Gerontology and Geriatrics, Leiden University Medical Center, Leiden, The Netherlands
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
| | - J C Bis
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - G M Peloso
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
| | - J A Brody
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - L Broer
- Department of Internal Medicine, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - E L Busch
- Channing Division of Network Medicine, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - Q Duan
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - A M Stilp
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - C J O'Donnell
- Department of Medicine, Harvard University, Boston, MA, USA
- National Heart, Lung, and Blood Institute Framingham Heart Study, Framingham, MA, USA
- Cardiology Section, Boston Veterans Administration Healthcare, Boston, MA, USA
| | - P W Macfarlane
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
| | - J S Floyd
- Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - J A Kors
- Department of Medical Informatics, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - H J Lin
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
- Division of Medical Genetics, Department of Pediatrics, Harbor-UCLA Medical Center, Torrance, CA, USA
| | - R Li-Gao
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - T Sofer
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - R Méndez-Giráldez
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - S R Cummings
- California Pacific Medical Center Research Institute, San Francisco, CA, USA
| | - S R Heckbert
- Department of Epidemiology, University of Washington, Seattle, WA, USA
| | - A Hofman
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - I Ford
- Robertson Center for Biostatistics, University of Glasgow, Glasgow, UK
| | - Y Li
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
- Department of Computer Science, University of North Carolina, Chapel Hill, NC, USA
| | - L J Launer
- Laboratory of Epidemiology, Demography, and Biometry, National Institute on Aging, Bethesda, MD, USA
| | - K Porthan
- Division of Cardiology, Heart and Lung Center, Helsinki University Central Hospital, Helsinki, Finland
| | - C Newton-Cheh
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
- Center for Human Genetic Research, Massachusetts General Hospital, Boston, MA, USA
- Program in Medical and Population Genetics, Broad Institute, Cambridge, MA, USA
- Cardiovascular Research Center, Massachusetts General Hospital, Boston, MA, USA
| | - M D Napier
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - K F Kerr
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - A P Reiner
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Public Health Sciences Division, Fred Hutchinson Cancer Research Center, Seattle, WA, USA
| | - K M Rice
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - J Roach
- Research Computing Center, University of North Carolina, Chapel Hill, NC, USA
| | - B M Buckley
- Department of Pharmacology and Therapeutics, University College Cork, Cork, Ireland
| | - E Z Soliman
- Epidemiology Cardiology Research Center (EPICARE), Wake Forest School of Medicine, Winston-Salem, NC, USA
| | - R de Mutsert
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - N Sotoodehnia
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Division of Cardiology, University of Washington, Seattle, WA, USA
- Cardiovascular Health Research Unit, Department of Medicine, University of Washington, Seattle, WA, USA
| | - A G Uitterlinden
- Department of Internal Medicine, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - K E North
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - C R Lee
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, NC, USA
| | - V Gudnason
- Icelandic Heart Association, Kopavogur, Iceland
- Department of Medicine, University of Iceland, Reykjavik, Iceland
| | - T Stürmer
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Center for Pharmacoepidemiology, University of North Carolina, Chapel Hill, NC, USA
| | - F R Rosendaal
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
| | - K D Taylor
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - K L Wiggins
- Department of Medicine, University of Washington, Seattle, WA, USA
| | - J G Wilson
- Department of Physiology and Biophysics, University of Mississippi Medical Center, Jackson, MS, USA
| | - Y-Di Chen
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - R C Kaplan
- Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
| | - K Wilhelmsen
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- The Renaissance Computing Institute, Chapel Hill, NC, USA
| | - L A Cupples
- Department of Biostatistics, Boston University School of Public Health, Boston, MA, USA
- National Heart, Lung, and Blood Institute Framingham Heart Study, Framingham, MA, USA
| | - V Salomaa
- Department of Health, THL-National Institute for Health and Welfare, Helsinki, Finland
| | - C van Duijn
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
| | - J W Jukema
- Department of Cardiology, Leiden University Medical Center, Leiden, The Netherlands
- Durrer Center for Cardiogenetic Research, Amsterdam, The Netherlands
- Interuniversity Cardiology Institute of the Netherlands, Utrecht, The Netherlands
| | - Y Liu
- Department of Epidemiology and Prevention, Division of Public Health Sciences, Wake Forest University, Winston-Salem, NC, USA
| | - D O Mook-Kanamori
- Department of Clinical Epidemiology, Leiden University Medical Center, Leiden, The Netherlands
- Department of Public Health and Primary Care, Leiden University Medical Center, Leiden, the Netherlands
- Department of BESC, Epidemiology Section, King Faisal Specialist Hospital and Research Centre, Riyadh, Saudi Arabia
| | - L A Lange
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - R S Vasan
- National Heart, Lung, and Blood Institute Framingham Heart Study, Framingham, MA, USA
- Division of Preventive Medicine and Epidemiology, Department of Epidemiology, Boston University School of Medicine, Boston, MA, USA
| | - A V Smith
- Icelandic Heart Association, Kopavogur, Iceland
- Department of Medicine, University of Iceland, Reykjavik, Iceland
| | - B H Stricker
- Department of Epidemiology, Erasmus MC-University Medical Center Rotterdam, Rotterdam, The Netherlands
- Inspectorate of Health Care, Utrecht, The Netherlands
| | - C C Laurie
- Department of Biostatistics, University of Washington, Seattle, WA, USA
| | - J I Rotter
- Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA, USA
| | - E A Whitsel
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Department of Medicine, University of North Carolina, Chapel Hill, NC, USA
| | - B M Psaty
- Department of Medicine, University of Washington, Seattle, WA, USA
- Department of Epidemiology, University of Washington, Seattle, WA, USA
- Department of Health Services, University of Washington, Seattle, WA, USA
- Group Health Research Institute, Group Health Cooperative, Seattle, WA, USA
| | - C L Avery
- Department of Epidemiology, University of North Carolina, Chapel Hill, NC, USA
- Carolina Population Center, University of North Carolina, Chapel Hill, NC, USA
| |
Collapse
|
5
|
Affiliation(s)
- J. D. Stewart
- Atomic Energy of Canada Limited, Chalk River, Ontario, Canada
| |
Collapse
|
6
|
|
7
|
Stewart JD, Marchan R. Polymorphisms hit the headlines. Arch Toxicol 2012; 86:1799-801. [PMID: 23135550 DOI: 10.1007/s00204-012-0973-5] [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: 10/27/2022]
|
8
|
Stewart JD, Marchan R. Polymorphisms hit the headlines. Arch Toxicol 2012; 86:1637-9. [DOI: 10.1007/s00204-012-0941-0] [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: 11/29/2022]
|
9
|
Stewart JD, Marchan R. Current developments in toxicology. EXCLI J 2012; 11:692-702. [PMID: 27231472 PMCID: PMC4876666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/30/2012] [Accepted: 10/30/2012] [Indexed: 11/23/2022]
Affiliation(s)
- J. D. Stewart
- Leibniz-Institut für Arbeitsforschung an der TU Dortmund, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Ardeystrasse 67, 44139 Dortmund, Germany
| | - R. Marchan
- Leibniz-Institut für Arbeitsforschung an der TU Dortmund, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Ardeystrasse 67, 44139 Dortmund, Germany,*To whom correspondence should be addressed: R. Marchan, Leibniz-Institut für Arbeitsforschung an der TU Dortmund, Leibniz Research Centre for Working Environment and Human Factors (IfADo), Ardeystrasse 67, 44139 Dortmund, Germany, E-mail:
| |
Collapse
|
10
|
|
11
|
|
12
|
|
13
|
Fratter C, Gorman GS, Stewart JD, Buddles M, Smith C, Evans J, Seller A, Poulton J, Roberts M, Hanna MG, Rahman S, Omer SE, Klopstock T, Schoser B, Kornblum C, Czermin B, Lecky B, Blakely EL, Craig K, Chinnery PF, Turnbull DM, Horvath R, Taylor RW. The clinical, histochemical, and molecular spectrum of PEO1 (Twinkle)-linked adPEO. Neurology 2010; 74:1619-26. [PMID: 20479361 DOI: 10.1212/wnl.0b013e3181df099f] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND Mutations in the Twinkle (PEO1) gene are a recognized cause of autosomal dominant progressive external ophthalmoplegia (adPEO), resulting in the accumulation of multiple mitochondrial DNA (mtDNA) deletions and cytochrome c oxidase (COX)-deficient fibers in skeletal muscle secondary to a disorder of mtDNA maintenance. Patients typically present with isolated extraocular muscle involvement, with little apparent evidence of the clinical heterogeneity documented in other mtDNA maintenance disorders, in particular POLG-related disease. METHODS We reviewed the clinical, histochemical, and molecular genetics analysis of 33 unreported patients from 26 families together with all previous cases described in the literature to define the clinical phenotype associated with PEO1 mutations. RESULTS Ptosis and ophthalmoparesis were almost universal clinical features among this cohort, with 52% (17/33) reporting fatigue and 33% (11/33) having mild proximal myopathy. Features consistent with CNS involvement were rarely described; however, in 24% (8/33) of the patients, cardiac abnormalities were reported. Mitochondrial histochemical changes observed in muscle showed remarkable variability, as did the secondary mtDNA deletions, which in some patients were only detected by PCR-based assays and not Southern blotting. Moreover, we report 7 novel PEO1 variants. CONCLUSIONS Our data suggest a shared clinical phenotype with variable mild multiorgan involvement, and that the contribution of PEO1 mutations as a cause of adPEO may well be underestimated. Direct sequencing of the PEO1 gene should be considered in adPEO patients prior to muscle biopsy.
Collapse
Affiliation(s)
- C Fratter
- Oxford Medical Genetics Laboratories, Churchill Hospital, Oxford, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
14
|
Yu-Wai-Man P, Griffiths PG, Gorman GS, Lourenco CM, Wright AF, Auer-Grumbach M, Toscano A, Musumeci O, Valentino ML, Caporali L, Lamperti C, Tallaksen CM, Duffey P, Miller J, Whittaker RG, Baker MR, Jackson MJ, Clarke MP, Dhillon B, Czermin B, Stewart JD, Hudson G, Reynier P, Bonneau D, Marques W, Lenaers G, McFarland R, Taylor RW, Turnbull DM, Votruba M, Zeviani M, Carelli V, Bindoff LA, Horvath R, Amati-Bonneau P, Chinnery PF. Multi-system neurological disease is common in patients with OPA1 mutations. ACTA ACUST UNITED AC 2010; 133:771-86. [PMID: 20157015 PMCID: PMC2842512 DOI: 10.1093/brain/awq007] [Citation(s) in RCA: 314] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Additional neurological features have recently been described in seven families transmitting pathogenic mutations in OPA1, the most common cause of autosomal dominant optic atrophy. However, the frequency of these syndromal 'dominant optic atrophy plus' variants and the extent of neurological involvement have not been established. In this large multi-centre study of 104 patients from 45 independent families, including 60 new cases, we show that extra-ocular neurological complications are common in OPA1 disease, and affect up to 20% of all mutational carriers. Bilateral sensorineural deafness beginning in late childhood and early adulthood was a prominent manifestation, followed by a combination of ataxia, myopathy, peripheral neuropathy and progressive external ophthalmoplegia from the third decade of life onwards. We also identified novel clinical presentations with spastic paraparesis mimicking hereditary spastic paraplegia, and a multiple sclerosis-like illness. In contrast to initial reports, multi-system neurological disease was associated with all mutational subtypes, although there was an increased risk with missense mutations [odds ratio = 3.06, 95% confidence interval = 1.44-6.49; P = 0.0027], and mutations located within the guanosine triphosphate-ase region (odds ratio = 2.29, 95% confidence interval = 1.08-4.82; P = 0.0271). Histochemical and molecular characterization of skeletal muscle biopsies revealed the presence of cytochrome c oxidase-deficient fibres and multiple mitochondrial DNA deletions in the majority of patients harbouring OPA1 mutations, even in those with isolated optic nerve involvement. However, the cytochrome c oxidase-deficient load was over four times higher in the dominant optic atrophy + group compared to the pure optic neuropathy group, implicating a causal role for these secondary mitochondrial DNA defects in disease pathophysiology. Individuals with dominant optic atrophy plus phenotypes also had significantly worse visual outcomes, and careful surveillance is therefore mandatory to optimize the detection and management of neurological disability in a group of patients who already have significant visual impairment.
Collapse
Affiliation(s)
- P Yu-Wai-Man
- Mitochondrial Research Group, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
15
|
Yu-Wai-Man P, Stewart JD, Hudson G, Andrews RM, Griffiths PG, Birch MK, Chinnery PF. OPA1 increases the risk of normal but not high tension glaucoma. J Med Genet 2009; 47:120-5. [PMID: 19581274 DOI: 10.1136/jmg.2009.067512] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
BACKGROUND Primary open angle glaucoma is a progressive optic neuropathy characterised by the selective loss of retinal ganglion cells, pathological optic disc cupping and visual field defects. The OPA1 gene encodes an inner mitochondrial membrane protein crucial for normal mitochondrial function, and pathogenic mutations cause autosomal dominant optic atrophy by specifically targeting retinal ganglion cells. This raises the distinct possibility that more subtle genetic variations in OPA1 could alter the risk of developing glaucoma. METHODS 137 patients with primary open angle glaucoma (67 patients with high-tension glaucoma (HTG), 70 patients with normal-tension glaucoma (NTG)) and 75 controls from the North East of England were studied. Three single-nucleotide polymorphisms in intron 8 (IVS8+4c-->t and IVS8+32t-->c) and exon 4 (c.473A-->G) of the OPA1 gene were genotyped in the study group. In addition, the entire OPA1 coding region was sequenced in 24 individuals with the CT/TT compound genotype using standard BigDye chemistries. RESULTS There was no difference in either allele or genotype frequency for the IVS8+32t-->c single-nucleotide polymorphisms between patients and controls, but there was a significant association between the T allele at IVS8+4c-->t and the risk of developing NTG (OR=2.04, 95% CI=1.10 to 3.81, p=0.004), but not HTG. Logistic regression analysis also confirmed a strong association between the CT/TT compound genotype at IVS8+4 and IVS8+32 with NTG (OR=29.75, 95% CI=3.83 to 231.21, p=0.001). CONCLUSIONS The CT/TT compound genotype at IVS8+4 and IVS8+32 is a strong genetic risk determinant for NTG but not HTG.
Collapse
|
16
|
|
17
|
Stewart JD, Hudson G, Yu-Wai-Man P, Blakeley EL, He L, Horvath R, Maddison P, Wright A, Griffiths PG, Turnbull DM, Taylor RW, Chinnery PF. OPA1 IN MULTIPLE MITOCHONDRIAL DNA DELETION DISORDERS. Neurology 2008; 71:1829-31. [DOI: 10.1212/01.wnl.0000335931.54095.0a] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
|
18
|
Stewart JD, Tennant S, Powell H, Pyle A, Blakely EL, He L, Hudson G, Roberts M, du Plessis D, Gow D, Mewasingh LD, Hanna MG, Omer S, Morris AA, Roxburgh R, Livingston JH, McFarland R, Turnbull DM, Chinnery PF, Taylor RW. Novel POLG1 mutations associated with neuromuscular and liver phenotypes in adults and children. J Med Genet 2008; 46:209-14. [DOI: 10.1136/jmg.2008.058180] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
|
19
|
|
20
|
Drapanas T, McDonald JC, Stewart JD. Serotonin Release Following Instillation of Hypertonic Glucose into the Proximal Intestine. Ann Surg 2007; 156:528-36. [PMID: 17859708 PMCID: PMC1466258 DOI: 10.1097/00000658-196210000-00002] [Citation(s) in RCA: 85] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
21
|
|
22
|
|
23
|
|
24
|
|
25
|
Affiliation(s)
- J D Stewart
- Surgical Laboratories of the Harvard Medical School at the Massachusetts General Hospital, Boston
| | | |
Collapse
|
26
|
Affiliation(s)
- J D Stewart
- Surgical Laboratories of the Harvard Medical School at the Massachusetts General Hospital, Boston
| | | |
Collapse
|
27
|
Affiliation(s)
- J D Stewart
- Surgical Laboratories of the Harvard Medical School at the Massachusetts General Hospital, Boston
| | | |
Collapse
|
28
|
Stewart JD, Rourke GM. CHANGES IN BLOOD AND INTERSTITIAL FLUID RESULTING FROM SURGICAL OPERATION AND ETHER ANESTHESIA. J Clin Invest 2006; 17:413-6. [PMID: 16694587 PMCID: PMC434796 DOI: 10.1172/jci100967] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Affiliation(s)
- J D Stewart
- Surgical Laboratories of the Harvard Medical School at the Massachusetts General Hospital, Boston
| | | |
Collapse
|
29
|
Valdmanis PN, Simões Lopes AA, Gros-Louis F, Stewart JD, Rouleau GA, Dupré N. A novel neurodegenerative disease characterised by posterior column ataxia and pyramidal tract involvement maps to chromosome 8p12-8q12.1. J Med Genet 2004; 41:634-9. [PMID: 15286160 PMCID: PMC1735870 DOI: 10.1136/jmg.2004.019711] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
30
|
|
31
|
Boehlein SK, Nakatsu T, Hiratake J, Thirumoorthy R, Stewart JD, Richards NG, Schuster SM. Characterization of inhibitors acting at the synthetase site of Escherichia coli asparagine synthetase B. Biochemistry 2001; 40:11168-75. [PMID: 11551215 DOI: 10.1021/bi0155551] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [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: 11/28/2022]
Abstract
Asparagine synthetase catalyzes the ATP-dependent formation of L-asparagine from L-aspartate and L-glutamine, via a beta-aspartyl-AMP intermediate. Since interfering with this enzyme activity might be useful for treating leukemia and solid tumors, we have sought small-molecule inhibitors of Escherichia coli asparagine synthetase B (AS-B) as a model system for the human enzyme. Prior work showed that L-cysteine sulfinic acid competitively inhibits this enzyme by interfering with L-aspartate binding. Here, we demonstrate that cysteine sulfinic acid is also a partial substrate for E. coli asparagine synthetase, acting as a nucleophile to form the sulfur analogue of beta-aspartyl-AMP, which is subsequently hydrolyzed back to cysteine sulfinic acid and AMP in a futile cycle. While cysteine sulfinic acid did not itself constitute a clinically useful inhibitor of asparagine synthetase B, these results suggested that replacing this linkage by a more stable analogue might lead to a more potent inhibitor. A sulfoximine reported recently by Koizumi et al. as a competitive inhibitor of the ammonia-dependent E. coli asparagine synthetase A (AS-A) [Koizumi, M., Hiratake, J., Nakatsu, T., Kato, H., and Oda, J. (1999) J. Am. Chem. Soc. 121, 5799-5800] can be regarded as such a species. We found that this sulfoximine also inhibited AS-B, effectively irreversibly. Unlike either the cysteine sulfinic acid interaction with AS-B or the sulfoximine interaction with AS-A, only AS-B productively engaged in asparagine synthesis could be inactivated by the sulfoximine; free enzyme was unaffected even after extended incubation with the sulfoximine. Taken together, these results support the notion that sulfur-containing analogues of aspartate can serve as platforms for developing useful inhibitors of AS-B.
Collapse
Affiliation(s)
- S K Boehlein
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, Florida 32610, USA
| | | | | | | | | | | | | |
Collapse
|
32
|
Christensen HD, Gonzalez CL, Stewart JD, Rayburn WF. Multiple courses of antenatal betamethasone and cognitive development of mice offspring. J Matern Fetal Med 2001; 10:269-76. [PMID: 11531154 DOI: 10.1080/714904336] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 09/30/2022]
Abstract
OBJECTIVE To measure the effect of multiple courses of antenatal betamethasone, used for lung maturation, on long-term cognition of mice offspring. METHODS Forty gravid CD-1 mice were randomly assigned to receive one of four treatments (n = 10 per group): 0.1 mg betamethasone or saline placebo, given subcutaneously either once daily on gestational days 13-16 or twice daily on days 14 and 15. This dose of betamethasone given on gestational day 14 causes fetal lung maturation in mice. Three offspring per gender in each litter underwent standard cognitive tasks as juveniles and as adults. Analysis of variance or Kruskal-Wallis testing was used to compare data. RESULTS Learning acquisition and memory were indistinguishable between the betamethasone-exposed and the corresponding placebo-exposed offspring when performing the following tasks: juvenile runway with adult memory, adult water runway and Morris spatial maze. This lack of difference in task performance between treatment groups persisted after controlling for gender and for each multiple-course regimen. CONCLUSION Multiple courses of antenatal corticosteroids did not impact the mouse offsprings' long-term learning and memory.
Collapse
Affiliation(s)
- H D Christensen
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City 73190, USA
| | | | | | | |
Collapse
|
33
|
Abstract
Improved stereoselectivity in dehydrogenase-mediated reductions has been achieved by rationally designed gene overexpression and knockouts in Saccharomyces cerevisiae cells and by isolating and characterizing novel dehydrogenases from other organisms. Transaminases have been used to prepare unnatural amines and amino acids in good yields, particularly when the equilibria are shifted by selective product removal.
Collapse
Affiliation(s)
- J D Stewart
- Department of Chemistry, University of Florida, Gainesville 32611, USA.
| |
Collapse
|
34
|
Rodríguez S, Kayser MM, Stewart JD. Highly stereoselective reagents for beta-keto ester reductions by genetic engineering of baker's yeast. J Am Chem Soc 2001; 123:1547-55. [PMID: 11456752 DOI: 10.1021/ja0027968] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
While whole cells of baker's yeast (Saccharomyces cerevisiae) are a convenient biocatalytic reducing agent for a wide variety of carbonyl compounds, mixtures of stereoisomeric alcohols are often observed since the organism contains a large number of reductase enzymes with overlapping substrate specificities but differing stereoselectivities. We sought to improve the performance of baker's yeast for beta-keto ester reductions by using recombinant DNA techniques to alter the levels of three enzymes known to play important roles in these reactions (fatty acid synthase, Fasp; aldo-keto reductase, Ypr1p; alpha-acetoxy ketone reductase, Gre2p). A complete set of "first-generation" yeast strains that either lack or overexpress each of these three enzymes was created and tested for improvements in stereoselective reductions of a series of beta-keto esters. On the basis of these results, multiply modified ("second-generation") strains were created that combined gene knockout and overexpression in single strains. In some cases, these additional modifications further improved the stereoselectivities of beta-keto ester reductions, thereby making several beta-hydroxy ester building blocks readily available by reactions that can be performed by nonspecialists. This work also revealed that additional yeast proteins participate in reducing beta-keto esters, and further progress using this strategy will require either additional genetic manipulations or the expression of yeast reductases in hosts that lack enzymes with overlapping substrate specificity.
Collapse
Affiliation(s)
- S Rodríguez
- Department of Chemistry, University of Florida, Gainesville, Florida 32611, USA
| | | | | |
Collapse
|
35
|
Mihovilovic MD, Chen G, Wang S, Kyte B, Rochon F, Kayser MM, Stewart JD. Asymmetric Baeyer-Villiger oxidations of 4-mono- and 4,4-disubstituted cyclohexanones by whole cells of engineered Escherichia coli. J Org Chem 2001; 66:733-8. [PMID: 11430090 DOI: 10.1021/jo001292p] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [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: 11/30/2022]
Abstract
Whole cells of an Escherichia coli strain that overexpresses Acinetobacter sp. NCIB 9871 cyclohexanone monooxygenase have been used for the Baeyer-Villiger oxidations of a variety of 4-mono- and 4,4-disubstituted cyclohexanones. In cases where comparisons were possible, this new biocatalytic reagent provided lactones with chemical yields and optical purities that were comparable to those obtained from the purified enzyme or a strain of bakers' yeast that expresses the same enzyme. The efficient production of cyclohexanone monooxygenase in the E. coli expression system (ca. 30% of total soluble protein) allowed these oxidations to reach completion in approximately half the time required for the engineered bakers' yeast strain. Surprisingly, 4,4-disubstituted cyclohexanones were also accepted by the enzyme, and the enantioselectivities of these oxidations could be rationalized by considering the conformational energies of bound substrates along with the enzyme's intrinsic enantioselectivity. The enzyme expressed in E. coli cells also oxidized several 4-substituted cyclohexanones bearing polar substituents, often with high enantioselectivities. In the case of 4-iodocyclohexanone, the lactone was obtained in > 98% ee and its absolute configuration was assigned by X-ray crystallography. The crystal belongs to the monoclinic P2(1) space group with a = 5.7400(10), b = 6.1650(10), c = 11.377(2) A, b = 99.98(2) degrees, and Z = 2. Taken together, these results demonstrate the utility of an engineered bacterial strain in delivering useful chiral building blocks in an experimentally simple manner.
Collapse
Affiliation(s)
- M D Mihovilovic
- Department of Chemistry, University of New Brunswick, P.O. Box 5050, Saint John, NB E2L 4L5, Canada
| | | | | | | | | | | | | |
Collapse
|
36
|
Sienko AE, Stewart JD, Gonzalez CL, Christensen HD, Lerner M, Rayburn WF. Placebo-controlled, blinded comparison of antenatal betamethasone on mouse liver development. Drug Chem Toxicol 2001; 24:49-61. [PMID: 11307634 DOI: 10.1081/dct-100103085] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [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: 11/03/2022]
Abstract
The objective of this investigation was to evaluate, in a placebo-controlled manner, the developing mouse liver after antenatal exposure either to a single dose or to a multidose of betamethasone. Ninety gravid CD-1 mice were randomly divided into three groups (n = 30/group) to receive either saline (0.25 mL s.c.) or betamethasone (0.10 mg s.c.) as a single dose on gestational day (GD) 14 of a 19-day gestation or as a 0.10 mg dose given twice daily on GD 14 and on GD 15 (4 doses). GD 0 is defined by the presence of a copulatory plug. These exposures of betamethasone cause fetal mouse lung maturation as would be observed in premature humans at 24-34 weeks of gestation. The livers were removed either from the fetuses on GD 16.5 or from the offspring on postnatal day 1, 3, 5, and 120. Special stains were used to evaluate hepatocyte architecture, glycoprotein and glycogen content, extramedullary hematopoiesis and iron storage. Hepatocyte intranuclear DNA content, cell size, and cell shape were measured by image analysis (CAS 200). At GD 16.5, betamethasone produced a significant decrease in the liver/body weight ratio that, when compared with the placebo group, was greater with the multidose (p < 0.01) than with the single dose (p < 0.05). 16.5 GD single dose hepatocytes were smaller in size as compared to placebo without impact on intranuclear DNA (p < 0.01). Single dose PND 1 hepatocytes demonstrated an increase in intranuclear DNA as compared to placebo but without change in cell size (p < 0.001). The prenatal reduced liver weight recovered in the newborn period. No difference in microscopic architecture of the hepatocytes or histologic differences between either of the three treatment groups was found in glycogen deposition, extramedullary hematopoiesis or iron metabolism at GD 16.5 and postnatally. It was concluded antenatal betamethasone can cause a decrease in the liver/body weight ratio in the fetal mouse that recovers eventually without any functional impact as assessed histologically.
Collapse
Affiliation(s)
- A E Sienko
- University of Oklahoma Health Sciences Center, Department of Pathology, BMSB Room 451, 940 Stanton Young Blvd., Oklahoma City, OK 73104, USA.
| | | | | | | | | | | |
Collapse
|
37
|
Rayburn WF, Gonzalez CL, Christensen HD, Stewart JD. Effect of prenatally administered hypericum (St John's wort) on growth and physical maturation of mouse offspring. Am J Obstet Gynecol 2001; 184:191-5. [PMID: 11174501 DOI: 10.1067/mob.2001.108339] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [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: 11/22/2022]
Abstract
OBJECTIVE Our purpose was to determine whether prenatal exposure to the herb hypericum (St John's wort) affects long-term growth and physical maturation of mouse offspring. STUDY DESIGN Forty CD-1 mice were randomly assigned to receive daily doses of either 180 mg/kg per day hypericum (n = 20) or a placebo (n = 20) for 2 weeks before conception and throughout gestation. Perinatal outcomes, growth, and physical milestones of the offspring were compared in a blinded manner. Variables were compared by analysis of variance or by chi2 testing. RESULTS The gestational ages at delivery and litter sizes did not differ between the hypericum-exposed and the placebo-exposed offspring. The body weight, body length, and head circumference measurements from postnatal day 3 through adulthood increased in a manner that was indistinguishable between the two groups of offspring, regardless of gender. No differences in reaching physical milestones (teeth eruptions, eye opening, external genitalia) were noted between the 2 groups. The reproductive capability, perinatal outcomes, and growth and development of the second-generation offspring were unaffected by hypericum exposure. CONCLUSION Maternal administration of hypericum before and throughout gestation did not affect long-term growth and physical maturation of exposed mouse offspring.
Collapse
Affiliation(s)
- W F Rayburn
- Section of Maternal-Fetal Medicine, Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, USA
| | | | | | | |
Collapse
|
38
|
Christensen HD, Gonzalez CL, Stewart JD, Rayburn WF. Multiple courses of antenatal betamethasone and cognitive development of mice offspring. J Matern Fetal Neonatal Med 2001. [DOI: 10.1080/jmf.10.4.269.276] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
39
|
Abstract
BACKGROUND Idiopathic autonomic neuropathy is a severe, subacute disorder with a presumed autoimmune basis. It is indistinguishable from the subacute autonomic neuropathy that may accompany lung cancer or other tumors. Autoantibodies specific for nicotinic acetylcholine receptors in the autonomic ganglia are potentially pathogenic and may serve as serologic markers of various forms of autoimmune autonomic neuropathy. METHODS We tested serum from 157 patients with a variety of types of dysautonomia. Immunoprecipitation assays with iodine-125-labeled epibatidine and solubilized human neuroblastoma acetylcholine receptors were used to detect autoantibodies that bound to or blocked ganglionic receptors. RESULTS Ganglionic-receptor-binding antibodies were found in 19 of 46 patients with idiopathic or paraneoplastic autonomic neuropathy (41 percent), in 6 of 67 patients with postural tachycardia syndrome, idiopathic gastrointestinal dysmotility, or diabetic autonomic neuropathy (9 percent), and in none of 44 patients with other autonomic disorders. High levels of the binding antibodies correlated with more severe autonomic dysfunction (including the presence of tonic pupils). Levels of these antibodies decreased in patients who had clinical improvement. All seven patients with ganglionic-receptor-blocking antibodies had ganglionic-receptor-binding antibodies and had idiopathic or paraneoplastic autonomic neuropathy. CONCLUSIONS Seropositivity for antibodies that bind to or block ganglionic acetylcholine receptors identifies patients with various forms of autoimmune autonomic neuropathy and distinguishes these disorders from other types of dysautonomia. The positive correlation between high levels of ganglionic-receptor antibodies and the severity of autonomic dysfunction suggests that the antibodies have a pathogenic role in these types of neuropathy.
Collapse
Affiliation(s)
- S Vernino
- Department of Neurology, Mayo Clinic, Rochester, Minn 55905, USA.
| | | | | | | | | | | |
Collapse
|
40
|
Abstract
Asymmetric ketone reductions remain the most popular application of baker's yeast (Saccharomyces cerevisiae) in organic synthesis and data from the genome sequencing project is beginning to have an impact on improving the stereoselectivities of these reactions, augmenting traditional approaches based on selective inhibition. In addition, the catalytic repertoire of yeast has been expanded to include chiral ketone oxidations by overexpression of a bacterial Baeyer-Villiger monooxygenase.
Collapse
Affiliation(s)
- J D Stewart
- Department of Chemistry, University of Florida, Gainesville 32611, USA.
| |
Collapse
|
41
|
Rayburn WF, Sienko AE, Gonzalez CL, Christensen HD, Kupiec TC, Paulsen AL, Stewart JD. Impact of antenatal exposure of mice to fenfluramine on cardiac development and long-term growth of the offspring. Drug Chem Toxicol 2000; 23:419-31. [PMID: 10959545 DOI: 10.1081/dct-100100126] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The objective of this investigation was to determine, in a placebo-controlled manner, whether antenatal exposure to formulations of fenfluramine and dexfenfluramine impacted cardiac development and long-term growth of exposed mice offspring. One hundred forty-four CD-1 mice were randomized to six treatment groups (n=23 or 25) to obtain, per group, 5 gravids for killing on gestational day (GD) 15 and < or =10 deliveries for assessing growth of the offspring. Either fenfluramine preparation was administered in feed bars in two doses: 1 and 3.2 times the equivalent human daily dosage according to body surface area. The drugs were given from 2 weeks before mating until GD 15. The mice ingested each drug at target values, averaging 10.5+/-0.3 and 31.8+/-1.9 mg/kg/d for fenfluramine and 5.0+/-0.2 and 16.2+/-0.4 mg/kg/d for dexfenfluramine. The drug concentration was about 36% in the fetal brain compared with the adult brain. The maternal and the offspring hearts, including mitral and aortic valves, of fenfluramine-exposed mice were indistinguishable from the placebo-exposed mice. The duration of gestation and the litter size were the same between the treatment groups. The mean body weights, body lengths, and head circumferences and early functional testing did not differ significantly between the fenfluramine or dexfenfluramine-exposed offspring and the placebo-exposed offspring. There were no significant treatment differences in growth measured as body weights to PND 120. Neither fenfluramine formulation, given before conception and during gestation, impacted cardiac development and long-term growth of the mice offspring.
Collapse
Affiliation(s)
- W F Rayburn
- Department of Obstetrics and Gynecology, The University of Oklahoma Health Sciences Center, Oklahoma City, USA.
| | | | | | | | | | | | | |
Collapse
|
42
|
Rodríguez S, Schroeder KT, Kayser MM, Stewart JD. Asymmetric synthesis of beta-hydroxy esters and alpha-alkyl-beta-hydroxy esters by recombinant Escherichia coli expressing enzymes from baker's yeast. J Org Chem 2000; 65:2586-7. [PMID: 10789479 DOI: 10.1021/jo9917036] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- S Rodríguez
- Department of Chemistry, University of Florida, Gainesville 32611, USA
| | | | | | | |
Collapse
|
43
|
Rayburn WF, Gonzalez CL, Christensen HD, Kupiec TC, Jacobsen JA, Stewart JD. Effect of antenatal exposure to paroxetine (paxil) on growth and physical maturation of mice offspring. J Matern Fetal Med 2000; 9:136-41. [PMID: 10902830 DOI: 10.1002/(sici)1520-6661(200003/04)9:2<136::aid-mfm10>3.0.co;2-q] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
OBJECTIVE Our purpose was to determine, in a placebo-controlled manner, whether antenatal exposure to paroxetine affected long-term growth and physical maturation of mice offspring. METHODS Forty-one CD-1 mice consumed paroxetine (n = 21) or a placebo (n = 20) for 2 weeks before conception and throughout gestation. The daily dose of paroxetine (Paxil; 30 mg/kg/d) was known to achieve concentrations in the serum equivalent to the upper therapeutic level in humans and in the fetal brain equivalent to that of the adult mouse. Growth and physical maturation of the offspring were compared by paired t-test, Welch's corrected test, and Fisher's exact test. RESULTS The maternal weight gain, litter sizes, number of fetal resorptions, and gestational age at delivery were not different between the paroxetine and the placebo-exposed offspring. Newborn pups exposed to paroxetine were more likely to have low birthweights (1.65 gm vs. 1.70 gm; P < 0.05) and narrower heads (7.7 mm vs. 8.1 mm; P < 0.05). Body weight, body length, and head circumference measurements increased in a manner that was indistinguishable between the two groups of offspring, regardless of gender. No differences in achievement of physical milestones (lower incisor eruption, eye opening, and development of external genitalia) were noted between the two groups. The reproductive capability and the perinatal outcomes of the second-generation offspring were unaffected by paroxetine exposure. CONCLUSION A clinically relevant dose of paroxetine, when given throughout gestation, did not affect long-term growth and physical maturation of mice offspring.
Collapse
Affiliation(s)
- W F Rayburn
- Department of Obstetrics and Gynecology, University of Oklahoma Health Sciences Center, Oklahoma City, USA.
| | | | | | | | | | | |
Collapse
|
44
|
Abstract
Clostripain (EC 3.4.22.8) has been shown to be superior to trypsin as a means of activating serum procarboxypeptidase A. With this activation and a previously described assay for carboxypeptidase A it has been possible to determine the concentration of procarboxypeptidase A in human serum. In order to establish a baseline in the healthy adult a survey of the procarboxypeptidase A content of the serum of 66 blood donors was carried out. An average value of 9.7 microg/l was found for the proenzyme. This is in sharp contrast to a mean of 0.34 microg/l for the free enzyme present in serum that was not treated with clostripain [1].
Collapse
Affiliation(s)
- J D Stewart
- Department of Molecular Biology, Lewis Thomas Laboratory, Princeton University, Princeton, NJ 08544, USA
| | | |
Collapse
|
45
|
Stewart JD, Fowler CJ. Neurology of bladder, bowel and sexual dysfunction. J Clin Neuromuscul Dis 1999; 1:112. [PMID: 19078564 DOI: 10.1097/00131402-199912000-00012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- J D Stewart
- Boston: Butterworth- Heinemann, 1999. Price: $95.OO. Montreal, Canada
| | | |
Collapse
|
46
|
Stewart JD, Younger DS. Motor disorders. J Clin Neuromuscul Dis 1999; 1:113. [PMID: 19078565 DOI: 10.1097/00131402-199912000-00014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Affiliation(s)
- J D Stewart
- Philadelphia: Lippincott Williams & Wilkins, 1999. Price: $129.00 Montreal, Canada
| | | |
Collapse
|
47
|
Abstract
[formula: see text] The stereoselectivities of bakers' yeast catalyzed reductions of beta-keto esters can be manipulated by genetic design. Strains in which two major beta-keto ester reductases are either knocked out or overexpressed have been constructed. The former approach results in whole cell biocatalysts with reversed stereoselectivity from unmodified bakers' yeast while the latter shows useful improvements in stereoselectivity. These results indicate that the "designer yeast" approach can provide useful biocatalysts for these transformations.
Collapse
Affiliation(s)
- S Rodríguez
- Department of Chemistry, University of Florida, Gainesville 32611, USA
| | | | | |
Collapse
|
48
|
Kobayashi H, Kato J, Morioka H, Stewart JD, Ohtsuka E. Tryptophan H33 plays an important role in pyrimidine (6-4) pyrimidone photoproduct binding by a high-affinity antibody. Protein Eng 1999; 12:879-84. [PMID: 10556249 DOI: 10.1093/protein/12.10.879] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
The importance of Trp H33 in antibody recognition of DNA containing a central pyrimidine (6-4) pyrimidone photoproduct was investigated. This residue was replaced by Tyr, Phe and Ala and the binding abilities of these mutants were determined by surface plasmon resonance and fluorescence spectroscopy. Conservative substitution of Trp H33 by Tyr or Phe resulted in moderate losses of binding affinity; however, replacement by Ala had a significantly larger impact. The fluorescence properties of DNA containing a (6-4) photoproduct were strongly affected by the identity of the H33 residue. DNA binding by both the wild-type and the W-H33-Y mutant was accompanied by a small degree of fluorescence quenching; by contrast, binding by the W-H33-F and W-H33-A mutants produced large fluorescence increases. Taken together, these variations in binding and fluorescence properties with the identity of the H33 residue are consistent with a role in photoproduct recognition by Trp H33 in the high-affinity antibody 64M5.
Collapse
Affiliation(s)
- H Kobayashi
- Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita-ku, Sapporo 060-0812, Japan and the University of Florida, Gainesville, FL 32611, USA
| | | | | | | | | |
Collapse
|
49
|
Thayer MM, Olender EH, Arvai AS, Koike CK, Canestrelli IL, Stewart JD, Benkovic SJ, Getzoff ED, Roberts VA. Structural basis for amide hydrolysis catalyzed by the 43C9 antibody. J Mol Biol 1999; 291:329-45. [PMID: 10438624 DOI: 10.1006/jmbi.1999.2960] [Citation(s) in RCA: 48] [Impact Index Per Article: 1.9] [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: 11/22/2022]
Abstract
Among catalytic antibodies, the well-characterized antibody 43C9 is unique in its ability to catalyze the difficult, but desirable, reaction of selective amide hydrolysis. The crystallographic structures that we present here for the single-chain variable fragment of the 43C9 antibody, both with and without the bound product p -nitrophenol, strongly support and extend the structural and mechanistic information previously provided by a three-dimensional computational model, together with extensive biochemical, kinetics, and mutagenesis results. The structures reveal an unexpected extended beta-sheet conformation of the third complementarity determining region of the heavy chain, which may be coupled to the novel indole ring orientation of the adjacent Trp H103. This unusual conformation creates an antigen-binding site that is significantly deeper than predicted in the computational model, with a hydrophobic pocket that encloses the p -nitrophenol product. Despite these differences, the previously proposed roles for Arg L96 in transition-state stabilization and for His L91 as the nucleophile that forms a covalent acyl-antibody intermediate are fully supported by the crystallographic structures. His L91 is now centered at the bottom of the antigen-binding site with the imidazole ring poised for nucleophilic attack. His L91, Arg L96, and the bound p -nitrophenol are linked into a hydrogen-bonding network by two well-ordered water molecules. These water molecules may mimic the positions of the phosphonamidate oxygen atoms of the antigen, which in turn mimic the transition state of the reaction. This network also contains His H35, suggesting that this residue may also stabilize the transition-states. A possible proton-transfer pathway from His L91 through two tyrosine residues may assist nucleophilic attack. Although transition-state stabilization is commonly observed in esterolytic antibodies, nucleophilic attack appears to be unique to 43C9 and accounts for the unusually high catalytic activity of this antibody.
Collapse
Affiliation(s)
- M M Thayer
- Department of Molecular Biology, The Scripps Research Institute, La Jolla, CA, 92037, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
50
|
Schnizer HG, Boehlein SK, Stewart JD, Richards NG, Schuster SM. Formation and isolation of a covalent intermediate during the glutaminase reaction of a class II amidotransferase. Biochemistry 1999; 38:3677-82. [PMID: 10090755 DOI: 10.1021/bi981450v] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Incubation of Escherichia coli asparagine synthetase B (AS-B) with [14C]-L-glutamine gives a covalent adduct that can be isolated. Radiolabeled protein is not observed (i) when the wild-type enzyme is incubated with 6-diazo-5-oxo-L-norleucine (DON) prior to reaction with [14C]glutamine or (ii) when the C1A AS-B mutant is incubated with [14C]-L-glutamine. Both of these alterations eliminate the ability of the enzyme to utilize glutamine but do not affect ammonia-dependent asparagine synthesis. Formation of the covalent adduct therefore depends on the presence of the N-terminal active site cysteine, which has been shown to be essential for glutamine-dependent activity in this and other class II amidotransferases. The amount of covalent adduct exhibits saturation behavior with increasing concentrations of L-glutamine. The maximum observed quantity of this intermediate is consistent with its involvement on the main pathway of glutamine hydrolysis. The chemical properties of the isolable covalent adduct are consistent with those anticipated for the gamma-glutamyl thioester that has been proposed as an intermediate in the AS-B-catalyzed conversion of glutamine to glutamate. The covalent adduct is acid-stable but is labile under alkaline conditions. On the basis of the measured rates of formation and breakdown of this intermediate, it is kinetically competent to participate in the normal catalytic mechanism. These studies represent the first description of a thioester intermediate for any class II amidotransferase and represent an important step in gaining further insight into the kinetic and chemical mechanisms of AS-B.
Collapse
Affiliation(s)
- H G Schnizer
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | | | | | | | | |
Collapse
|