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Olaniyan T, Pinault L, Li C, van Donkelaar A, Meng J, Martin RV, Hystad P, Robichaud A, Ménard R, Tjepkema M, Bai L, Kwong JC, Lavigne E, Burnett RT, Chen H. Ambient air pollution and the risk of acute myocardial infarction and stroke: A national cohort study. Environ Res 2022; 204:111975. [PMID: 34478722 DOI: 10.1016/j.envres.2021.111975] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [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: 06/01/2021] [Revised: 07/27/2021] [Accepted: 08/24/2021] [Indexed: 05/07/2023]
Abstract
We used a large national cohort in Canada to assess the incidence of acute myocardial infarction (AMI) and stroke hospitalizations in association with long-term exposure to fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3). The study population comprised 2.7 million respondents from the 2006 Canadian Census Health and Environment Cohort (CanCHEC), followed for incident hospitalizations of AMI or stroke between 2006 and 2016. We estimated 10-year moving average estimates of PM2.5, NO2, and O3, annually. We used Cox proportional hazards models to examine the associations adjusting for various covariates. For AMI, each interquartile range (IQR) increase in exposure was found to be associated with a hazard ratio of 1.026 (95% CI: 1.007-1.046) for PM2.5, 1.025 (95% CI: 1.001-1.050) for NO2, and 1.062 (95% CI: 1.041-1.084) for O3, respectively. Similarly, for stroke, an IQR increase in exposure was associated with a hazard ratio of 1.078 (95% CI: 1.052-1.105) for PM2.5, 0.995 (95% CI: 0.965-1.030) for NO2, and 1.055 (95% CI: 1.028-1.082) for O3, respectively. We found consistent evidence of positive associations between long-term exposures to PM2.5, and O3, and to a lesser degree NO2, with incident AMI and stroke hospitalizations.
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Affiliation(s)
- Toyib Olaniyan
- Health Analysis Division, Statistics Canada, 100 Tunney's Pasture Driveway, Ottawa, Ontario, K1A 0T6, Canada.
| | - Lauren Pinault
- Health Analysis Division, Statistics Canada, 100 Tunney's Pasture Driveway, Ottawa, Ontario, K1A 0T6, Canada.
| | - Chi Li
- Department of Chemistry, University of California, Berkeley, CA, 94720, United States.
| | - Aaron van Donkelaar
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 3J5, Canada; Department of Energy, Environment & Chemical Engineering, Washington University in St Louis, St Louis, MO, 63130, United States.
| | - Jun Meng
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 3J5, Canada.
| | - Randall V Martin
- Department of Physics and Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, B3H 3J5, Canada; Department of Energy, Environment & Chemical Engineering, Washington University in St Louis, St Louis, MO, 63130, United States.
| | - Perry Hystad
- School of Biological & Population Health Sciences, College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, 97331, United States.
| | - Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, Québec, H9P 1J3, Canada.
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, Québec, H9P 1J3, Canada.
| | - Michael Tjepkema
- Health Analysis Division, Statistics Canada, 100 Tunney's Pasture Driveway, Ottawa, Ontario, K1A 0T6, Canada.
| | - Li Bai
- ICES, Toronto, Ontario, M4N 3M5, Canada.
| | - Jeffrey C Kwong
- ICES, Toronto, Ontario, M4N 3M5, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, M5T 3M7, Canada; Public Health Ontario, Toronto, Ontario, M5G 1V5, Canada.
| | - Eric Lavigne
- Air Health Science Division, Health Canada, Ottawa, Ontario, K1A 0L4, Canada; School of Epidemiology & Public Health, University of Ottawa, Ottawa, Ontario, K1N 6N5, Canada.
| | - Richard T Burnett
- Institute of Health Metrics & Evaluation, University of Washington, Seattle, WA, 98121, United States; Population Studies Division, Environmental Health and Research Bureau, Health Canada, Ottawa, Ontario K1A 0T6, Canada.
| | - Hong Chen
- ICES, Toronto, Ontario, M4N 3M5, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, M5T 3M7, Canada; Public Health Ontario, Toronto, Ontario, M5G 1V5, Canada; Population Studies Division, Environmental Health and Research Bureau, Health Canada, Ottawa, Ontario K1A 0T6, Canada.
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To T, Zhu J, Terebessy E, Zhang K, Fong I, Pinault L, Jerrett M, Robichaud A, Ménard R, van Donkelaar A, Martin RV, Hystad P, Brook JR, Dell S, Stieb D. Does exposure to air pollution increase the risk of acute care in young children with asthma? An Ontario, Canada study. Environ Res 2021; 199:111302. [PMID: 34019894 DOI: 10.1016/j.envres.2021.111302] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [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: 11/27/2020] [Revised: 05/04/2021] [Accepted: 05/05/2021] [Indexed: 06/12/2023]
Abstract
Owing to their greater outdoor activity and ongoing lung development, children are particularly vulnerable to the harmful effects of exposure to fine particulate matter (PM2.5). However, the effects of PM2.5 components are poorly understood. This study aimed to use a longitudinal birth cohort of children with physician-diagnosed incident asthma to investigate the effect of PM2.5 components at birth on morbidity measured by health services utilization. Of 1277 Toronto Child Health Evaluation Questionnaire (T-CHEQ) participants, the study population included 362 children diagnosed with asthma who were followed for a mean of 13 years from birth until March 31, 2016, or loss-to-follow-up. Concentrations of PM2.5 and its components were assigned based on participants' postal codes at birth. Study outcomes included counts of asthma, asthma-related, and all-cause health services use. Poisson regression in single-, two-, and multi-pollutant models was used to estimate rate ratios (RR) per interquartile range (IQR) increase of exposures. Covariates were included in all models to further adjust for potential confounding. The adjusted RR for sulfate (SO4) and all-cause hospitalizations was statistically significant with RR = 2.23 (95% confidence interval [CI]: 1.25-3.96) in a multi-pollutant model with nitrogen dioxide (NO2) and ozone (O3). In multi-pollutant models with oxidants, the adjusted RRs for SO4 of all-cause hospitalizations and emergency department (ED) visits were also statistically significant with RR = 2.31 (95% CI: 1.32-4.03) and RR = 1.39 (95% CI: 1.02-1.90), respectively. While unadjusted single-pollutant RRs for asthma-specific and asthma-related health services use with the SO4 component of PM2.5 were above one, none were statistically significant. This study found significant associations with exposure to SO4 in PM2.5 and all-cause acute care, chiefly for hospitalizations, in children with asthma.
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Affiliation(s)
- Teresa To
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada; Dalla Lana School of Public Health, University of Toronto, Canada; Institute for Clinical Evaluative Sciences, Ontario, Canada.
| | - Jingqin Zhu
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada; Institute for Clinical Evaluative Sciences, Ontario, Canada
| | - Emilie Terebessy
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada
| | - Kimball Zhang
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada; Institute for Clinical Evaluative Sciences, Ontario, Canada
| | - Ivy Fong
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Canada
| | | | - Michael Jerrett
- The University of California, Los Angeles, Fielding School of Public Health, CA, USA
| | - Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada
| | - Aaron van Donkelaar
- Department of Physics and Atmospheric Science, Dalhousie University, Canada; Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA
| | - Randall V Martin
- Department of Physics and Atmospheric Science, Dalhousie University, Canada; Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, St. Louis, MO, USA; Harvard-Smithsonian Center for Astrophysics, USA
| | - Perry Hystad
- College of Public Health and Human Sciences, Oregon State University, USA
| | - Jeffrey R Brook
- Dalla Lana School of Public Health, University of Toronto, Canada
| | - Sharon Dell
- Department of Pediatrics, Faculty of Medicine, University of British Columbia, Canada; Pediatric Respiratory Medicine, Provincial Health Services Authority, BC Children's Hospital, Canada
| | - Dave Stieb
- Environmental Health Science and Research Bureau, Health Canada, Canada
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Thomson EM, Christidis T, Pinault L, Tjepkema M, Colman I, Crouse DL, van Donkelaar A, Martin RV, Hystad P, Robichaud A, Ménard R, Brook JR, Burnett RT. Self-rated stress, distress, mental health, and health as modifiers of the association between long-term exposure to ambient pollutants and mortality. Environ Res 2020; 191:109973. [PMID: 32810502 DOI: 10.1016/j.envres.2020.109973] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [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: 03/20/2020] [Revised: 07/16/2020] [Accepted: 07/17/2020] [Indexed: 06/11/2023]
Abstract
BACKGROUND Individual and neighbourhood-scale socioeconomic characteristics modify associations between exposure to air pollution and mortality. The role of stress, which may integrate effects of social and environmental exposures on health, is unknown. We examined whether an individual's perspective on their own well-being, as assessed using self-rated measures of stress and health, modifies the pollutant-mortality relationship. METHODS The Canadian Community Health Survey (CCHS)-mortality cohort includes respondents from surveys administered between 2001 and 2012 linked to vital statistics and postal codes from 1981 until 2016. Annual fine particulate matter (PM2.5), nitrogen dioxide (NO2), and ozone (O3) exposure estimates were attached to a sample of cohort members aged 30-89 years (n = 398,300 respondents/3,848,400 person-years). We examined whether self-rated stress, distress, mental health, and general health modified associations between long-term exposure to each pollutant (three-year moving average with one-year lag) and non-accidental mortality using Cox survival models, adjusted for individual- (i.e. socioeconomic and behavioural) and neighbourhood-scale covariates. RESULTS In fully-adjusted models, the relationship between exposure to pollutants and mortality was stronger among those with poor self-rated mental health, including a significant difference for NO2 (hazard ratio (HR) = 1.15, 95% CI 1.06-1.25 per IQR) compared to those with very good/excellent mental health (HR = 1.05, 95% CI 1.01-1.08; Cochran's Q = 4.01; p < 0.05). Poor self-rated health was similarly associated with higher pollutant-associated HRs, but only in unadjusted models. Stress and distress did not modify pollutant-mortality associations. CONCLUSIONS Poor self-rated mental and general health were associated with increased mortality attributed to exposure to ambient pollutants.
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Affiliation(s)
- Errol M Thomson
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada; Department of Biochemistry, Microbiology and Immunology, University of Ottawa, ON, Canada.
| | | | - Lauren Pinault
- Health Analysis Division, Statistics Canada, Ottawa, ON, Canada
| | | | - Ian Colman
- School of Epidemiology and Public Health, University of Ottawa, Ottawa, ON, Canada
| | | | - Aaron van Donkelaar
- Department of Physics & Atmospheric Science, Dalhousie University, Halifax, NS, Canada; Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, MO, USA
| | - Randall V Martin
- Department of Physics & Atmospheric Science, Dalhousie University, Halifax, NS, Canada; Department of Energy, Environmental & Chemical Engineering, Washington University in St. Louis, MO, USA; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| | - Perry Hystad
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA
| | - Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, QC, Canada
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, QC, Canada
| | - Jeffrey R Brook
- Dalla Lana School of Public Health, University of Toronto, ON, Canada
| | - Richard T Burnett
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
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To T, Zhu J, Stieb D, Gray N, Fong I, Pinault L, Jerrett M, Robichaud A, Ménard R, van Donkelaar A, Martin RV, Hystad P, Brook JR, Dell S. Early life exposure to air pollution and incidence of childhood asthma, allergic rhinitis and eczema. Eur Respir J 2020; 55:13993003.00913-2019. [PMID: 31806712 PMCID: PMC7031706 DOI: 10.1183/13993003.00913-2019] [Citation(s) in RCA: 76] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 11/07/2019] [Indexed: 01/08/2023]
Abstract
Rationale There is growing evidence that air pollution may contribute to the development of childhood asthma and other allergic diseases. In this follow-up of the Toronto Child Health Evaluation Questionnaire (T-CHEQ) study, we examined associations between early life exposures to air pollution and incidence of asthma, allergic rhinitis and eczema from birth through adolescence. Methods 1286 T-CHEQ participants were followed from birth until outcome (March 31, 2016) or loss to follow-up, with a mean of 17 years of follow-up. Concentrations of nitrogen dioxide (NO2), ozone (O3) and particulate matter with a 50% cut-off aerodynamic diameter of 2.5 µm (PM2.5) from January 1, 1999 to December 31, 2012 were assigned to participants based on their postal codes at birth using ground observations, chemical/meteorological models, remote sensing and land-use regression models. Study outcomes included incidence of physician-diagnosed asthma, allergic rhinitis and eczema. Cox proportional hazard regression models were used to estimate hazard ratios per interquartile range of exposures and outcomes, adjusting for potential confounders. Results Hazard ratios of 1.17 (95% CI 1.05–1.31) for asthma and 1.07 (95% CI 0.99–1.15) for eczema were observed for total oxidants (O3 and NO2) at birth. No significant increase in risk was found for PM2.5. Conclusions Exposures to oxidant air pollutants (O3 and NO2) but not PM2.5 were associated with an increased risk of incident asthma and eczema in children. This suggests that improving air quality may contribute to the prevention of asthma and other allergic disease in childhood and adolescence. This study found that exposure to total oxidants at birth increased the risk of developing asthma by 17% and eczema by 7%. Adverse impacts of exposure to air pollutants, particularly ozone and nitrogen dioxide, may have their origins in early life.http://bit.ly/33PClYN
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Affiliation(s)
- Teresa To
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada .,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada.,Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
| | - Jingqin Zhu
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.,Institute for Clinical Evaluative Sciences, Toronto, ON, Canada
| | - Dave Stieb
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, ON, Canada
| | - Natasha Gray
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Ivy Fong
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Lauren Pinault
- Analytical Studies Branch, Statistics Canada, Ottawa, ON, Canada
| | - Michael Jerrett
- Fielding School of Public Health, The University of California, Los Angeles, CA, USA
| | - Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, QC, Canada
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, QC, Canada
| | - Aaron van Donkelaar
- Dept of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada.,Dept of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, MO, USA
| | - Randall V Martin
- Dept of Physics and Atmospheric Science, Dalhousie University, Halifax, NS, Canada.,Dept of Energy, Environmental and Chemical Engineering, Washington University in St Louis, St Louis, MO, USA.,Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| | - Perry Hystad
- College of Public Health and Human Sciences, Oregon State University, Corvallis, OR, USA
| | - Jeffrey R Brook
- Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Sharon Dell
- Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.,Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
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Stieb DM, Yao J, Henderson SB, Pinault L, Smith-Doiron MH, Robichaud A, van Donkelaar A, Martin RV, Ménard R, Brook JR. Variability in ambient ozone and fine particle concentrations and population susceptibility among Canadian health regions. Can J Public Health 2019; 110:149-158. [PMID: 30617991 PMCID: PMC6964403 DOI: 10.17269/s41997-018-0169-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2017] [Accepted: 12/14/2018] [Indexed: 12/11/2022]
Abstract
Objectives To estimate the proportion of the Canadian population that is more susceptible to adverse effects of ozone (O3) and fine particle (PM2.5) air pollution exposure and how this varies by health region alongside ambient concentrations of O3 and PM2.5. Methods Using data from the census, the Canadian Community Health Survey, vital statistics and published literature, we generated cross-sectional estimates for 2014 of the proportions of the Canadian population considered more susceptible due to age, chronic disease, pregnancy, outdoor work, socio-economic status, and diet. We also estimated 2010–2012 average concentrations of O3 and PM2.5. Analyses were conducted nationally and for 110 health regions. Results Restrictive criteria (age < 10 or ≥ 75; asthma, chronic obstructive pulmonary disease, heart disease, or diabetes; pregnancy) suggested that approximately one third of the Canadian population is more susceptible, while inclusive criteria (restrictive plus age 10–19 and 65–74, outdoor work, less than high school education, low vitamin C intake) increased this proportion to approximately two thirds. Across health regions, estimates ranged from 24.4% to 41.2% (restrictive) and 61.2% to 87.0% (inclusive). Ten health regions were in the highest quartile of both population susceptibility and O3 or PM2.5 concentrations, all of which were outside major urban centres. Conclusions A substantial proportion of the Canadian population exhibits at least one risk factor that increases their susceptibility to adverse effects of O3 and PM2.5 exposure. Both risk communication and management interventions need to be increasingly targeted to regions outside large urban centres in the highest quartiles of both susceptibility and exposure. Electronic supplementary material The online version of this article (10.17269/s41997-018-0169-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- David M Stieb
- Health Canada, Environmental Health Science and Research Bureau, Federal Tower, 420-747 West Hastings St., Vancouver, BC, V6C 1A1, Canada. .,School of Epidemiology and Public Health, University of Ottawa, Room 101 600 Peter Morand Crescent, Ottawa, ON, K1G 5Z3, Canada.
| | - Jiayun Yao
- British Columbia Centre for Disease Control, 655 W 12th Ave, Vancouver, BC, V5Z 4R4, Canada.,School of Population and Public Health, University of British Columbia, 2206 E Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Sarah B Henderson
- British Columbia Centre for Disease Control, 655 W 12th Ave, Vancouver, BC, V5Z 4R4, Canada.,School of Population and Public Health, University of British Columbia, 2206 E Mall, Vancouver, BC, V6T 1Z3, Canada
| | - Lauren Pinault
- Analytical Studies Branch, Statistics Canada, 100 Tunney's Pasture Driveway, Ottawa, ON, K1A 0T6, Canada
| | - Marc H Smith-Doiron
- Health Canada, Environmental Health Science and Research Bureau, Federal Tower, 420-747 West Hastings St., Vancouver, BC, V6C 1A1, Canada
| | - Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada, 2121, route Transcanadienne, Dorval, QC, H9P 1J3, Canada
| | - Aaron van Donkelaar
- Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Randall V Martin
- Department of Physics and Atmospheric Science, Dalhousie University, 6310 Coburg Road, PO Box 15000, Halifax, NS, B3H 4R2, Canada
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada, 2121, route Transcanadienne, Dorval, QC, H9P 1J3, Canada
| | - Jeffrey R Brook
- Air Quality Research Division, Environment and Climate Change Canada, 4905 Dufferin St, 4th Floor, Office 4S310, Toronto, ON, M3H 5T4, Canada.,Dalla Lana School of Public Health, University of Toronto, Health Sciences Building 155 College Street, 6th Floor, Toronto, ON, M5T 3M7, Canada
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Crouse DL, Balram A, Hystad P, Pinault L, van den Bosch M, Chen H, Rainham D, Thomson EM, Close CH, van Donkelaar A, Martin RV, Ménard R, Robichaud A, Villeneuve PJ. Associations between Living Near Water and Risk of Mortality among Urban Canadians. Environ Health Perspect 2018; 126:077008. [PMID: 30044232 PMCID: PMC6108828 DOI: 10.1289/ehp3397] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Revised: 04/21/2018] [Accepted: 06/03/2018] [Indexed: 05/20/2023]
Abstract
BACKGROUND Increasing evidence suggests that residential exposures to natural environments, such as green spaces, are associated with many health benefits. Only a single study has examined the potential link between living near water and mortality. OBJECTIVE We sought to examine whether residential proximity to large, natural water features (e.g., lakes, rivers, coasts, "blue space") was associated with cause-specific mortality. METHODS Our study is based on a population-based cohort of nonimmigrant adults living in the 30 largest Canadian cities [i.e., the 2001 Canadian Census Health and Environment Cohort) (CanCHEC)]. Subjects were drawn from the mandatory 2001 Statistics Canada long-form census, who were linked to the Canadian mortality database and to annual income-tax filings, through 2011. We estimated associations between living within of blue space and deaths from several common causes of death. We adjusted models for many personal and contextual covariates, as well as for exposures to residential greenness and ambient air pollution. RESULTS Our cohort included approximately 1.3 million subjects at baseline, 106,180 of whom died from nonaccidental causes during follow-up. We found significant, reduced risks of mortality in the range of 12-17% associated with living within of water in comparison with living farther away, among all causes of death examined, except with external/accidental causes. Protective effects were found to be higher among women and all older adults than among other subjects, and protective effects were found to be highest against deaths from stroke and respiratory-related causes. CONCLUSIONS Our findings suggest that living near blue spaces in urban areas has important benefits to health, but further work is needed to better understand the drivers of this association. https://doi.org/10.1289/EHP3397.
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Affiliation(s)
- Dan L Crouse
- Department of Sociology, University of New Brunswick, Fredericton, New Brunswick, Canada
- New Brunswick Institute for Research, Data, and Training, Fredericton, New Brunswick, Canada
| | - Adele Balram
- New Brunswick Institute for Research, Data, and Training, Fredericton, New Brunswick, Canada
| | - Perry Hystad
- College of Public Health & Human Sciences, Oregon State University, Corvallis, Oregon, USA
| | - Lauren Pinault
- Health Analysis Division, Statistics Canada, Ottawa, Ontario, Canada
| | - Matilda van den Bosch
- Department of Forest and Conservation Sciences, University of British Columbia, Vancouver, British Columbia, Canada
- School of Population and Public Health, University of British Columbia, Vancouver, British Columbia, Canada
| | - Hong Chen
- Public Health Ontario, Toronto, Ontario, Canada
- Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada
- Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Daniel Rainham
- Healthy Populations Institute, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Errol M Thomson
- Environmental Health Science and Research Bureau, Health Canada, Ottawa, Ontario, Canada
| | | | - Aaron van Donkelaar
- Department of Physics & Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Randall V Martin
- Department of Physics & Atmospheric Science, Dalhousie University, Halifax, Nova Scotia, Canada
- Harvard-Smithsonian Center for Astrophysics, Cambridge, Massachusetts, USA
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, Quebec, Canada
| | - Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, Quebec, Canada
| | - Paul J Villeneuve
- Department of Health Sciences, Carleton University, Ottawa, Ontario, Canada
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7
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Crouse DL, Pinault L, Balram A, Hystad P, Peters PA, Chen H, van Donkelaar A, Martin RV, Ménard R, Robichaud A, Villeneuve PJ. Urban greenness and mortality in Canada's largest cities: a national cohort study. Lancet Planet Health 2017; 1:e289-e297. [PMID: 29851627 DOI: 10.1016/s2542-5196(17)30118-3] [Citation(s) in RCA: 169] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Revised: 08/04/2017] [Accepted: 09/11/2017] [Indexed: 05/20/2023]
Abstract
BACKGROUND Findings from published studies suggest that exposure to and interactions with green spaces are associated with improved psychological wellbeing and have cognitive, physiological, and social benefits, but few studies have examined their potential effect on the risk of mortality. We therefore undertook a national study in Canada to examine associations between urban greenness and cause-specific mortality. METHODS We used data from a large cohort study (the 2001 Canadian Census Health and Environment Cohort [2001 CanCHEC]), which consisted of approximately 1·3 million adult (aged ≥19 years), non-immigrant, urban Canadians in 30 cities who responded to the mandatory 2001 Statistics Canada long-form census. The cohort has been linked by Statistics Canada to the Canadian mortality database and to annual income tax filings through 2011. We measured greenness with images from the moderate-resolution imaging spectroradiometer from NASA's Aqua satellite. We assigned estimates of exposure to greenness derived from remotely sensed Normalized Difference Vegetation Index (NDVI) within both 250 m and 500 m of participants' residences for each year during 11 years of follow-up (between 2001 and 2011). We used Cox proportional hazards models to estimate associations between residential greenness (as a continuous variable) and mortality. We estimated hazard ratios (HRs) and corresponding 95% CIs per IQR (0·15) increase in NDVI adjusted for personal (eg, education and income) and contextual covariates, including exposures to fine particulate matter, ozone, and nitrogen dioxide. We also considered effect modification by selected personal covariates (age, sex, household income adequacy quintiles, highest level of education, and marital status). FINDINGS Our cohort consisted of approximately 1 265 000 individuals at baseline who contributed 11 523 770 person-years. We showed significant decreased risks of mortality in the range of 8-12% from all causes of death examined with increased greenness around participants' residence. In the fully adjusted analyses, the risk was significantly decreased for all causes of death (non-accidental HR 0·915, 95% CI 0·905-0·924; cardiovascular plus diabetes 0·911, 0·895-0·928; cardiovascular 0·911, 0·894-0·928; ischaemic heart disease 0·904, 0·882-0·927; cerebrovascular 0·942, 0·902-0·983; and respiratory 0·899, 0·869-0·930). Greenness associations were more protective among men than women (HR 0·880, 95% CI 0·868-0·893 vs 0·955, 0·941-0·969), and among individuals with higher incomes (highest quintile 0·812, 0·791-0·834 vs lowest quintile 0·991, 0·972-1·011) and more education (degree or more 0·816, 0·791-0·842 vs did not complete high school 0·964, 0·950-0·978). INTERPRETATION Increased amounts of residential greenness were associated with reduced risks of dying from several common causes of death among urban Canadians. We identified evidence of inequalities, both in terms of exposures to greenness and mortality risks, by personal socioeconomic status among individuals living in generally similar environments, and with reasonably similar access to health care and other social services. The findings support the development of policies related to creating greener and healthier cities. FUNDING None.
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Affiliation(s)
- Dan L Crouse
- Department of Sociology, University of New Brunswick, Fredericton, NB, Canada; New Brunswick Institute for Research, Data, and Training, Fredericton, NB, Canada.
| | - Lauren Pinault
- Health Analysis Division, Statistics Canada, Ottawa, ON, Canada
| | - Adele Balram
- New Brunswick Institute for Research, Data, and Training, Fredericton, NB, Canada
| | - Perry Hystad
- College of Public Health & Human Sciences, Oregon State University, Corvallis, OR, USA
| | - Paul A Peters
- New Brunswick Institute for Research, Data, and Training, Fredericton, NB, Canada; Department of Health Sciences, Carleton University, Ottawa, ON, Canada
| | - Hong Chen
- Public Health Ontario, Toronto, ON, Canada; Institute for Clinical Evaluative Sciences, Toronto, ON, Canada; Dalla Lana School of Public Health, University of Toronto, Toronto, ON, Canada
| | - Aaron van Donkelaar
- Department of Physics & Atmospheric Science, Dalhousie University, Halifax, NS, Canada
| | - Randall V Martin
- Department of Physics & Atmospheric Science, Dalhousie University, Halifax, NS, Canada; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, QC, Canada
| | - Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada, Dorval, QC, Canada
| | - Paul J Villeneuve
- Department of Health Sciences, Carleton University, Ottawa, ON, Canada
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Ménard R, Deshaies-Jacques M, Gasset N. A comparison of correlation-length estimation methods for the objective analysis of surface pollutants at Environment and Climate Change Canada. J Air Waste Manag Assoc 2016; 66:874-895. [PMID: 27104336 DOI: 10.1080/10962247.2016.1177620] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 03/29/2016] [Accepted: 04/01/2016] [Indexed: 06/05/2023]
Abstract
UNLABELLED An objective analysis is one of the main components of data assimilation. By combining observations with the output of a predictive model we combine the best features of each source of information: the complete spatial and temporal coverage provided by models, with a close representation of the truth provided by observations. The process of combining observations with a model output is called an analysis. To produce an analysis requires the knowledge of observation and model errors, as well as its spatial correlation. This paper is devoted to the development of methods of estimation of these error variances and the characteristic length-scale of the model error correlation for its operational use in the Canadian objective analysis system. We first argue in favor of using compact support correlation functions, and then introduce three estimation methods: the Hollingsworth-Lönnberg (HL) method in local and global form, the maximum likelihood method (ML), and the [Formula: see text] diagnostic method. We perform one-dimensional (1D) simulation studies where the error variance and true correlation length are known, and perform an estimation of both error variances and correlation length where both are non-uniform. We show that a local version of the HL method can capture accurately the error variances and correlation length at each observation site, provided that spatial variability is not too strong. However, the operational objective analysis requires only a single and globally valid correlation length. We examine whether any statistics of the local HL correlation lengths could be a useful estimate, or whether other global estimation methods such as by the global HL, ML, or [Formula: see text] should be used. We found in both 1D simulation and using real data that the ML method is able to capture physically significant aspects of the correlation length, while most other estimates give unphysical and larger length-scale values. IMPLICATIONS This paper describes a proposed improvement of the objective analysis of surface pollutants at Environment and Climate Change Canada (formerly known as Environment Canada). Objective analyses are essentially surface maps of air pollutants that are obtained by combining observations with an air quality model output, and are thought to provide a complete and more accurate representation of the air quality. The highlight of this study is an analysis of methods to estimate the model (or background) error correlation length-scale. The error statistics are an important and critical component to the analysis scheme.
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Affiliation(s)
- Richard Ménard
- a Modeling and Integration Section, Air Quality Research Division , Environment and Climate Change Canada , Dorval , Quebec , Canada
| | - Martin Deshaies-Jacques
- a Modeling and Integration Section, Air Quality Research Division , Environment and Climate Change Canada , Dorval , Quebec , Canada
| | - Nicolas Gasset
- a Modeling and Integration Section, Air Quality Research Division , Environment and Climate Change Canada , Dorval , Quebec , Canada
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9
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Robichaud A, Ménard R, Zaïtseva Y, Anselmo D. Multi-pollutant surface objective analyses and mapping of air quality health index over North America. Air Qual Atmos Health 2016; 9:743-759. [PMID: 27785157 PMCID: PMC5054062 DOI: 10.1007/s11869-015-0385-9] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/07/2015] [Accepted: 11/23/2015] [Indexed: 05/23/2023]
Abstract
Air quality, like weather, can affect everyone, but responses differ depending on the sensitivity and health condition of a given individual. To help protect exposed populations, many countries have put in place real-time air quality nowcasting and forecasting capabilities. We present in this paper an optimal combination of air quality measurements and model outputs and show that it leads to significant improvements in the spatial representativeness of air quality. The product is referred to as multi-pollutant surface objective analyses (MPSOAs). Moreover, based on MPSOA, a geographical mapping of the Canadian Air Quality Health Index (AQHI) is also presented which provides users (policy makers, public, air quality forecasters, and epidemiologists) with a more accurate picture of the health risk anytime and anywhere in Canada and the USA. Since pollutants can also behave as passive atmospheric tracers, they provide information about transport and dispersion and, hence, reveal synoptic and regional meteorological phenomena. MPSOA could also be used to build air pollution climatology, compute local and national trends in air quality, and detect systematic biases in numerical air quality (AQ) models. Finally, initializing AQ models at regular time intervals with MPSOA can produce more accurate air quality forecasts. It is for these reasons that the Canadian Meteorological Centre (CMC) in collaboration with the Air Quality Research Division (AQRD) of Environment Canada has recently implemented MPSOA in their daily operations.
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Affiliation(s)
- Alain Robichaud
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans Canada Highway, Dorval, Québec H9P 1J3 Canada
| | - Richard Ménard
- Air Quality Research Division, Environment and Climate Change Canada, 2121 Trans Canada Highway, Dorval, Québec H9P 1J3 Canada
| | - Yulia Zaïtseva
- Canadian Meteorological Centre, Environment and Climate Change Canada, 2121 Trans Canada Highway, Dorval, Québec H9P 1J3 Canada
| | - David Anselmo
- Canadian Meteorological Centre, Environment and Climate Change Canada, 2121 Trans Canada Highway, Dorval, Québec H9P 1J3 Canada
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10
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Ménard R, Sansonetti P. Signaux moléculaires induisant l'entrée des bactéries entéropathogènes dans les cellules épithéliales: convergences et paradoxes. ACTA ACUST UNITED AC 2012. [DOI: 10.4267/10608/765] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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11
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Ménard R, Lachapelle M, Zador M. Interaction of (dien)Pd(II) with cytidine and cytidine 5'-monophosphate. Influence of the phosphate group on the kinetics and mechanism. Biophys Chem 2008; 20:29-37. [PMID: 17005148 DOI: 10.1016/0301-4622(84)80003-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/1983] [Accepted: 01/05/1984] [Indexed: 11/22/2022]
Abstract
The kinetics and the equilibrium of (dien)PdCl+ interaction with cytidine (C) and cytidine 5'-monophosphate (CMP) were studied by spectrophotometry and by stopped-flow methods. In both cases, the mechanism implies a (dien)Pd(H2O)2+ intermediate with a significant contribution of the solvent path at low chloride concentrations. With CMP, the rate is affected due to the addition of a mechanistic path via an intermediate formed between (dien)Pd(II) and the phosphate group of CMP. The kinetic and thermodynamic parameters have been determined and reflect the favorable electrostatic interactions due to the presence of the phosphate group of CMP. Furthermore, these parameters are in agreement with a transient (dien)Pd(II)-phosphate complex of CMP leading to the formation of the thermodynamically favored (dien)Pd(II)-N3 complex as final product.
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Affiliation(s)
- R Ménard
- Département de Chimie, Université de Montréal, C.P. 6210, succ.A, Montreal, Quebec H3C 3VI, Canada
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12
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Tarasick DW, Moran MD, Thompson AM, Carey-Smith T, Rochon Y, Bouchet VS, Gong W, Makar PA, Stroud C, Ménard S, Crevier LP, Cousineau S, Pudykiewicz JA, Kallaur A, Moffet R, Ménard R, Robichaud A, Cooper OR, Oltmans SJ, Witte JC, Forbes G, Johnson BJ, Merrill J, Moody JL, Morris G, Newchurch MJ, Schmidlin FJ, Joseph E. Comparison of Canadian air quality forecast models with tropospheric ozone profile measurements above midlatitude North America during the IONS/ICARTT campaign: Evidence for stratospheric input. ACTA ACUST UNITED AC 2007. [DOI: 10.1029/2006jd007782] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.1] [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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13
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Ménard R. [Malaria: parasite imaging unveils the intimacy of infection]. ACTA ACUST UNITED AC 2006; 55:219-21. [PMID: 17055669 DOI: 10.1016/j.patbio.2006.08.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2006] [Accepted: 08/04/2006] [Indexed: 11/27/2022]
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14
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Ménard R, Hulet C, Burdin G, Jarry A, Locker B, Vielpeau C. 40 - Résultats à long terme de la réparation du ménisque médial associée à une greffe du LCA : à propos de 58 lésions médiales. ACTA ACUST UNITED AC 2005; 91:71. [PMID: 16609591 DOI: 10.1016/s0035-1040(05)84546-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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15
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Abstract
To determine whether cathepsins and matrix metalloproteinase-1 are involved in accelerating tissue destruction, we examined, immunohistochemically, the expression of matrix metalloproteinase-1 and cathepsins B, D, L, and X in periprosthetic synovial-like interface tissues from 14 patients with failed prosthetic hips and in the synovial membranes of hips from 18 patients with rheumatoid arthritis and 25 patients with primary osteoarthritis. The expression levels of all these proteases in the interface tissue were higher than in the synovial membrane of osteoarthritis. The expression levels of cathepsins B and X in the interface tissue were higher than in the rheumatoid synovium. The results show similarities in the expression patterns of cathepsins D and L and matrix metalloproteinase-1 between aseptic prosthetic loosening and rheumatoid arthritis. In addition, these data suggest that the impact of cathepsins B and X on tissue degradation is more pronounced in aseptic prosthetic loosening than in rheumatoid arthritis.
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Affiliation(s)
- A Kido
- Department of Pathology, Otto-von-Guericke University, Magdeburg, Germany.
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16
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Natarajan R, Thathy V, Mota MM, Hafalla JC, Ménard R, Vernick KD. Fluorescent Plasmodium berghei sporozoites and pre-erythrocytic stages: a new tool to study mosquito and mammalian host interactions with malaria parasites. Cell Microbiol 2001; 3:371-9. [PMID: 11422080 DOI: 10.1046/j.1462-5822.2001.00117.x] [Citation(s) in RCA: 89] [Impact Index Per Article: 3.9] [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: 11/20/2022]
Abstract
To track malaria parasites for biological studies within the mosquito and mammalian hosts, we constructed a stably transformed clonal line of Plasmodium berghei, PbFluspo, in which sporogonic and pre-erythrocytic liver-stage parasites are autonomously fluorescent. A cassette containing the structural gene for the FACS-adapted green fluorescent protein mutant 2 (GFPmut2), expressed from the 5' and 3' flanking sequences of the circumsporozoite (CS) protein gene, was integrated and expressed at the endogenous CS locus. Recombinant parasites, which bear a wild-type copy of CS, generated highly fluorescent oocysts and sporozoites that invaded mosquito salivary glands and were transmitted normally to rodent hosts. The parasites infected cultured hepatocytes in vitro, where they developed into fluorescent pre-erythrocytic forms. Mammalian cells infected by these parasites can be separated from non-infected cells by fluorescence activated cell sorter (FACS) analysis. These fluorescent insect and mammalian stages of P. berghei should be useful for phenotypic studies in their respective hosts, as well as for identification of new genes expressed in these parasite stages.
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Affiliation(s)
- R Natarajan
- Department of Medical and Molecular Parasitology, New York University School of Medicine, 341 East 25th Street, New York, NY 10010, USA
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17
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Ménard R, Therrien C, Lachance P, Sulea T, Qo H, Alvarez-Hernandez AD, Roush WR. Cathepsins X and B display distinct activity profiles that can be exploited for inhibitor design. Biol Chem 2001; 382:839-45. [PMID: 11517939 DOI: 10.1515/bc.2001.102] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The carboxypeptidase and endopeptidase activities of cathepsins X and B, as well as their inhibition by E-64 derivatives, have been investigated in detail and compared. The results clearly demonstrate that cathepsins X and B do not share similar activity profiles against substrates and inhibitors. Using quenched fluorogenic substrates, we show that cathepsin X preferentially cleaves substrates through a monopeptidyl carboxypeptidase pathway, while cathepsin B displays a preference for the dipeptidyl pathway. The preference for one or the other pathway is about the same for both enzymes, i. e. approximately 2 orders of magnitude. Cleavage of a C-terminal dipeptide of a substrate by cathepsin X can be observed under conditions that preclude efficient monopeptidyl carboxypeptidase activity. In addition, an inhibitor designed to exploit the unique structural features responsible for the carboxypeptidase activity of cathepsin X has been synthesized and tested against cathepsins X, B and L. Although of moderate potency, this E-64 derivative is the first reported example of a cathepsin X-specific inhibitor. By comparison, CA074 was found to inactivate cathepsin B at least 34000-fold more efficiently than cathepsin X.
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Affiliation(s)
- R Ménard
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec
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18
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Lima AP, dos Reis FC, Serveau C, Lalmanach G, Juliano L, Ménard R, Vernet T, Thomas DY, Storer AC, Scharfstein J. Cysteine protease isoforms from Trypanosoma cruzi, cruzipain 2 and cruzain, present different substrate preference and susceptibility to inhibitors. Mol Biochem Parasitol 2001; 114:41-52. [PMID: 11356512 DOI: 10.1016/s0166-6851(01)00236-5] [Citation(s) in RCA: 61] [Impact Index Per Article: 2.7] [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: 11/29/2022]
Abstract
Cysteine-proteinases from parasitic protozoa have been recently characterized as factors of virulence and pathogenicity in several human and veterinary diseases. In Chagas' disease, the chronic infection caused by Trypanosoma cruzi, structure-functional studies on cysteine proteases were thus far limited to the parasite's major isoform, a cathepsin L-like lysosomal protease designated as cruzipain, cruzain or GP57/51. Encoded by a large gene family, cruzipain is efficiently targeted by synthetic inhibitors, which prevent parasite intracellular growth and differentiation. We have previously demonstrated that the multicopy cruzipain gene family includes polymorphic sequences, which could encode functionally different isoforms. We report here a comparative kinetic study between cruzain, the archetype of the cruzipain family, and an isoform, termed cruzipain 2, which is expressed preferentially by the mammalian stages of T. cruzi. Heterologous expression of the catalytic domain of cruzipain 2 in Saccharomyces cerevisae yielded an enzyme that differs markedly from cruzain with respect to pH stability, substrate specificity and sensitivity to inhibition by natural and synthetic inhibitors of cysteine proteases. We suggest that the structural-functional diversification imparted by genetic polymorphism of cruzipain genes may have contributed to T. cruzi adaptation to vertebrate hosts.
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Affiliation(s)
- A P Lima
- Laboratory of Molecular Immunology, Instituto de Biofísica Carlos Chagas Filho, Bloco G, CCS, UFRJ, Ilha do Fundão, RJ, CEP 21-944-900, Rio de Janeiro, Brazil.
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19
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Therrien C, Lachance P, Sulea T, Purisima EO, Qi H, Ziomek E, Alvarez-Hernandez A, Roush WR, Ménard R. Cathepsins X and B can be differentiated through their respective mono- and dipeptidyl carboxypeptidase activities. Biochemistry 2001; 40:2702-11. [PMID: 11258881 DOI: 10.1021/bi002460a] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [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
Several new cysteine proteases of the papain family have been discovered in the past few years. To help in the assignment of physiological roles and in the design of specific inhibitors, a clear picture of the specificities of these enzymes is needed. One of these novel enzymes, cathepsin X, displays a unique specificity, cleaving single amino acid residues at the C-terminus of substrates very efficiently. In this study, the carboxypeptidase activities and substrate specificity of cathepsins X and B have been investigated in detail and compared. Using quenched fluorogenic substrates and HPLC measurements, it was shown that cathepsin X preferentially cleaves substrates through a monopeptidyl carboxypeptidase pathway, while cathepsin B displays a preference for the dipeptidyl pathway. The preference for one or the other pathway is about the same for both enzymes, i.e., approximately 2 orders of magnitude, a result supported by molecular modeling of enzyme-substrate complexes. Cleavage of a C-terminal dipeptide of a substrate by cathepsin X can become more important under conditions that preclude efficient monopeptidyl carboxypeptidase activity, e.g., nonoptimal interactions in subsites S(2)-S(1). These results confirm that cathepsin X is designed to function as a monopeptidyl carboxypeptidase. Contrary to a recent report [Klemencic, I., et al. (2000) Eur. J. Biochem. 267, 5404-5412], it is shown that cathepsins X and B do not share similar activity profiles, and that reagents are available to clearly distinguish the two enzymes. In particular, CA074 was found to inactivate cathepsin B at least 34000-fold more efficiently than cathepsin X. The insights obtained from this and previous studies have been used to produce an inhibitor designed to exploit the unique structural features responsible for the carboxypeptidase activity of cathepsin X. Although of moderate potency, this E-64 derivative is the first reported example of a cathepsin X-specific inhibitor.
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Affiliation(s)
- C Therrien
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec H4P 2R2, Canada
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20
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Ménard R, Nägler DK, Zhang R, Tam W, Sulea T, Purisima EO. Human cathepsin X. A novel cysteine protease with unique specificity. Adv Exp Med Biol 2001; 477:317-22. [PMID: 10849759 DOI: 10.1007/0-306-46826-3_34] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Affiliation(s)
- R Ménard
- Biotechnology Research Institute, National Research Council of Canada, Montréal, Québec, Canada
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21
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Abstract
Apicomplexa constitute one of the largest phyla of protozoa. Most Apicomplexa, including those pathogenic to humans, are obligate intracellular parasites. Their extracellular forms, which are highly polarized and elongated cells, share two unique abilities: they glide on solid substrates without changing their shape and reach an intracellular compartment without active participation from the host cell. There is now ample ultrastructural evidence that these processes result from the backward movement of extracellular interactions along the anteroposterior axis of the parasite. Recent work in several Apicomplexa, including genetic studies in the Plasmodium sporozoite, has provided molecular support for this 'capping' model. It appears that the same machinery drives both gliding motility and host cell invasion. The cytoplasmic motor, a transmembrane bridge and surface ligands essential for cell invasion are conserved among the main apicomplexan pathogens.
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Affiliation(s)
- R Ménard
- Laboratoire de Biologie et Génétique du Paludisme, Institut Pasteur, Paris, France.
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22
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Ménard R, Scherf A. L'impact de la génétique inverse dans l'étude de la biologie de Plasmodium et de la physiopathologie du paludisme. Med Sci (Paris) 2001. [DOI: 10.4267/10608/1996] [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: 11/30/2022] Open
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23
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Affiliation(s)
- R Ménard
- Laboratoire de Biologie et Genetique du Paludisme, Institut Pasteur, 25 rue du Dr Roux, Paris, France.
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24
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Abstract
Malaria is transmitted to a mammalian host when the sporozoite stage of the Plasmodium parasite is injected by a mosquito vector. Sporozoites are unique in being able to interact with both hosts. Formed and released in the mosquito midgut, sporozoites bind to the salivary glands and invade their secretory cells. Once injected into the mammalian host, they home to the liver and invade hepatocytes. Recent work has shown that two sporozoite surface proteins, CS and TRAP, act in both hosts, perform multiple functions, and are each essential for the parasite at more than one step of its life cycle.
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Affiliation(s)
- R Ménard
- Department of Medical and Molecular Parasitology, NYU School of Medicine, NY, New York, USA
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25
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Sivaraman J, Nägler DK, Zhang R, Ménard R, Cygler M. Crystal structure of human procathepsin X: a cysteine protease with the proregion covalently linked to the active site cysteine. J Mol Biol 2000; 295:939-51. [PMID: 10656802 DOI: 10.1006/jmbi.1999.3410] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.6] [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
Human cathepsin X is one of many proteins discovered in recent years through the mining of sequence databases. Its sequence shows clear homology to cysteine proteases from the papain family, containing the characteristic residue patterns, including the active site. However, the proregion of cathepsin X is only 38 residues long, the shortest among papain-like enzymes, and the cathepsin X sequence has an atypical insertion in the regions proximal to the active site. This protein was recently expressed and partially characterized biochemically. Unlike most other cysteine proteases from the papain family, procathepsin X is incapable of autoprocessing in vitro but can be processed under reducing conditions by exogenous cathepsin L. Atypically, the mature enzyme is primarily a carboxypeptidase and has extremely poor endopeptidase activity. We have determined the three-dimensional structure of the procathepsin X at 1.7 A resolution. The overall structure of the mature enzyme is characteristic for enzymes of the papain superfamily, but contains several novel features. Most interestingly, the short proregion binds to the enzyme with the aid of a covalent bond between the cysteine residue in the proregion (Cys10p) and the active site cysteine residue (Cys31). This is the first example of a zymogen in which the inhibition of enzyme's proteolytic activity by the proregion is achieved through a reversible covalent modification of the active site nucleophile. Such mode of binding requires less contact area between the proregion and the enzyme than observed in other procathepsins, and no auxiliary binding site on the enzyme surface is used. A three-residue insertion in a highly conserved region, just prior to the active site cysteine residue, confers a significantly different shape on the S' subsites, compared to other proteases from papain family. The 3D structure provides an explanation for the rather unusual carboxypeptidase activity of this enzyme and confirms the predictions based on homology modeling. Another long insertion in the cathepsin X amino acid sequence forms a beta-hairpin pointing away from the active site. This insertion, thought to be an equivalent of cathepsin B occluding loop, is located on the side of the protein, distant from the substrate binding site.
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Affiliation(s)
- J Sivaraman
- Biotechnology Research Institute, National Research Council of Canada, 6100 Royalmount Avenue, Montréal, Québec, H4P 2R2, Canada
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Rayner PJ, Giering R, Kaminski T, Ménard R, Todling R, Trudinger CM. Exercises. Inverse Methods in Global Biogeochemical Cycles 2000. [DOI: 10.1029/gm114p0081] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
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Paugam L, Ménard R, Larue JP, Thouvenot D. Optimization of glucosinolate separation by micellar electrokinetic capillary chromatography using a Doehlert's experimental design. J Chromatogr A 1999; 864:155-62. [PMID: 10630880 DOI: 10.1016/s0021-9673(99)00924-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [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: 11/29/2022]
Abstract
The aim of this study was to optimize by micellar electrokinetic chromatography the separation of four glucosinolates, i.e. sinigrin, glucobrassicin and methoxyglucobrassicin involved in Cruciferae resistance mechanisms and glucotropaeolin used as an internal standard. The separation borate buffer which contained sodium dodecyl sulphate, tetramethylammonium hydroxide and methanol was firstly optimized by using a three variable Doehlert experimental design. The optimum concentrations found enabled, for the first time, to obtain an acceptable resolution between the two indole glucosinolates, glucobrassicin and methoxyglucobrassicin. Modifications of the method such as a capillary pre-rinse with pure borate buffer and a step change in voltage during experiment were performed to improve the resolutions between glucosinolates and to reduce the analysis time. This method was validated by a statistical analysis and showed good linearity, repeatability and reproducibility.
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Affiliation(s)
- L Paugam
- Laboratoire de Microbiologie et Sécurité Alimentaire, Technopôle Brest-Iroise, Plouzané, France
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Ménard R. [Genetic approach to the study of the sporogonic cycle in Plasmodium]. Bull Soc Pathol Exot 1999; 92:438. [PMID: 11000961] [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] [Subscribe] [Scholar Register] [Indexed: 02/17/2023]
Abstract
The development of transformation and mutagenesis techniques of the two species of Plasmodium most studied--Plasmodium falciparum (human parasite) and Plasmodium berghei (rodent parasite)--opens new perspectives for the molecular study on the parasite sporogonic cycle in the insect vector. The parasite's stages that can be genetically transformed (the asexual erythrocytic stages) and gametocytes. The function of proteins coded by genes present in single copy in the genome can thus be studied after only one recombination. Furthermore, most of the genes expressed during the sporogonic cycle are not during the erythrocytic stages, which makes possible the isolation of the erythrocytic cycles of parasites with a mutation in a gene which is essential to the development of the sporogonic cycle. Finally, the Plasmodium berghei model is particularly advantageous in that the entire cycle of this species of Plasmodium can be easily maintained in the laboratory. The species also appears to be easier to manipulate genetically than Plasmodium falciparum. Let us take the example of two surface proteins of Plasmodium sporozoites: the circumsporozoite proteins (CS) and the thrombospondin-related anonymous protein (TRAP). Both of these proteins have already been characterized in detail. Each of them possesses motives present in numerous protein of cell-cell or extracellular cell-matrice adhesion. The selective destruction of both genes has shown that both proteins also play a role in the development of the parasite within the mosquito. The CS protein is essential to the formation of sporozoites in the mosquito's intestinal oocysts, whereas the TRAP protein is essential for the sporozoites to have the power to invade the secreting cells of the mosquito's salivary glands as well as the host's hepatocytes. Using the mutagenous system for P. berghei should thus help elucidate the function of the important products expressed by the parasite during its development cycle in the vector mosquito as well as analyse the structure-function relationship of these products. It is possible that the molecular dissection of the parasite-mosquito interaction will lead to new approaches in the prevention of parasite transmission.
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Affiliation(s)
- R Ménard
- New York University, Medical Center, USA
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29
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Abstract
Cathepsin X is a novel cysteine protease which was identified recently from the EST (expressed sequence tags) database. In a homology model of the mature cathepsin X, a unique three residue insertion between the Gln22 of the oxyanion hole and the active site Cys31 was found to be located in the primed region of the binding cleft as part of a surface loop corresponding to residues His23 to Tyr27, which we have termed the "mini-loop". From the model, it became apparent that this distinctive structural feature might confer exopeptidase activity to the enzyme. To verify this hypothesis, human procathepsin X was expressed in Pichia pastoris and converted to mature cathepsin X using small amounts of human cathepsin L. Cathepsin X was found to display excellent carboxypeptidase activity against the substrate Abz-FRF(4NO(2)), with a k(cat)/K(M) value of 1.23 x 10(5) M(-)(1) s(-)(1) at the optimal pH of 5.0. However, the activity of cathepsin X against the substrates Cbz-FR-MCA and Abz-AFRSAAQ-EDDnp was found to be extremely low, with k(cat)/K(M) values lower than 70 M(-)(1) s(-)(1). Therefore, cathepsin X displays a stricter exopeptidase activity than cathepsin B. No inhibition of cathepsin X by cystatin C could be detected up to a concentration of 4 microM of inhibitor. From a model of the protease complexed with Cbz-FRF, the bound carboxypeptidase substrate is predicted to establish a number of favorable contacts within the cathepsin X binding site, in particular with residues His23 and Tyr27 from the mini-loop. The presence of the mini-loop restricts the accessibility of cystatin C as well as of the endopeptidase and MCA substrates in the primed subsites of the protease. The marked structural and functional differences of cathepsin X relative to other members of the papain family of cysteine proteases will be of great value in designing specific inhibitors useful as research tools to investigate the physiological and potential pathological roles of this novel enzyme.
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Affiliation(s)
- D K Nägler
- Biotechnology Research Institute, National Research Council of Canada, 6100 Avenue Royalmount, Montréal, Québec, Canada H4P 2R2
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30
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Doran JD, Nomizu M, Takebe S, Ménard R, Griffith D, Ziomek E. Autocatalytic processing of the streptococcal cysteine protease zymogen: processing mechanism and characterization of the autoproteolytic cleavage sites. Eur J Biochem 1999; 263:145-51. [PMID: 10429198 DOI: 10.1046/j.1432-1327.1999.00473.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The autocatalytic processing of the streptococcal cysteine protease zymogen (proSCP) to active streptococcal cysteine protease (SCP) was investigated in vitro using purified protein from Streptococcus pyogenes strain B220. It was found that the autocatalytic maturation of the zymogen proceeds through the sequential appearance of at least six intermediates, five of which were characterized through a combination of N-terminal sequencing and MS. Intermediates were identified as resulting from cleavages after Lys26, Asn41, Lys101, Ala112, and Lys118. Time-course studies of the proSCP processing gave a sigmoidal activity profile and indicated that proSCP catalyses its own transformation, mainly via an intermolecular processing mechanism. A similar sequential appearance of intermediates was observed when inactive Cys192Ser proSCP was treated with native, enzymatically active SCP, thus demonstrating that the maturation can exclusively proceed by a bimolecular mechanism. It was shown that proSCP, but not mature SCP, immobilized on a Sepharose resin is capable of liberating itself from the column, indicating that the zymogen is also capable of intramolecular processing. In order to test whether the amino acid sequences at the processing sites could be used for developing new, specific substrates, 3-amino benzoic acid octapeptide derivatives based on all five characterized amino acid sequences from the autoprocessing cleavage sites were synthesized and tested for activity. The 3-amino benzoic acid derivatives have kcat/KM values ranging from 1200 to 7700.M-1.s-1, making them very good endopeptidase substrates for SCP.
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Affiliation(s)
- J D Doran
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, Canada
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31
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Abstract
We present a new marker that confers both resistance to pyrimethamine and green fluorescent protein-based fluorescence on the malarial parasite Plasmodium berghei. A single copy of the cassette integrated into the genome is sufficient to direct fluorescence in parasites throughout the life cycle, in both its mosquito and vertebrate hosts. Erythrocyte stages of the parasite that express the marker can be sorted from control parasites by flow cytometry. Pyrimethamine pressure is not necessary for maintaining the cassette in transformed parasites during their sporogonic cycle in mosquitoes, including when it is borne by a plasmid. This tool should thus prove useful in molecular studies of P. berghei, both for generating parasite variants and monitoring their behavior.
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Affiliation(s)
- A A Sultan
- Michael Heidelberger Division of Immunology, Department of Pathology, Kaplan Cancer Center, New York University Medical Center, New York, New York 10016, USA
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32
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Nägler DK, Tam W, Storer AC, Krupa JC, Mort JS, Ménard R. Interdependency of sequence and positional specificities for cysteine proteases of the papain family. Biochemistry 1999; 38:4868-74. [PMID: 10200176 DOI: 10.1021/bi982632s] [Citation(s) in RCA: 56] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The specificity of cysteine proteases is characterized by the nature of the amino acid sequence recognized by the enzymes (sequence specificity) as well as by the position of the scissile peptide bond (positional specificity, i.e., endopeptidase, aminopeptidase, or carboxypeptidase). In this paper, the interdependency of sequence and positional specificities for selected members of this class of enzymes has been investigated using fluorogenic substrates where both the position of the cleavable peptide bond and the nature of the sequence of residues in P2-P1 are varied. The results show that cathepsins K and L and papain, typically considered to act strictly as endopeptidases, can also display dipeptidyl carboxypeptidase activity against the substrate Abz-FRF(4NO2)A and dipeptidyl aminopeptidase activity against FR-MCA. In some cases the activity is even equal to or greater than that observed with cathepsin B and DPP-I (dipeptidyl peptidase I), which have been characterized previously as exopeptidases. In contrast, the exopeptidase activities of cathepsins K and L and papain are extremely low when the P2-P1 residues are A-A, indicating that, as observed for the normal endopeptidase activity, the exopeptidase activities rely heavily on interactions in subsite S2 (and possibly S1). However, cathepsin B and DPP-I are able to hydrolyze substrates through the exopeptidase route even in absence of preferred interactions in subsites S2 and S1. This is attributed to the presence in cathepsin B and DPP-I of specific structural elements which serve as an anchor for the C- or N-terminus of a substrate, thereby allowing favorable enzyme-substrate interaction independently of the P2-P1 sequence. As a consequence, the nature of the residue at position P2 of a substrate, which is usually the main factor determining the specificity for cysteine proteases of the papain family, does not have the same contribution for the exopeptidase activities of cathepsin B and DPP-I.
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Affiliation(s)
- D K Nägler
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, H4P2R2, Canada
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33
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Nägler DK, Sulea T, Ménard R. Full-length cDNA of human cathepsin F predicts the presence of a cystatin domain at the N-terminus of the cysteine protease zymogen. Biochem Biophys Res Commun 1999; 257:313-8. [PMID: 10198209 DOI: 10.1006/bbrc.1999.0461] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.1] [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: 11/22/2022]
Abstract
A novel human cDNA encoding a cysteine protease of the papain family named cathepsin F is reported. The mature part of the predicted protease precursor displays between 26% and 42% identity to other human cysteine proteases while the proregion is unique by means of length and sequence. The very long proregion of the cathepsin F precursor (251 amino acid residues) can be divided into three regions: a C-terminal domain similar to the pro-segment of cathepsin L-like enzymes, a 50 residue flexible linker peptide, and an N-terminal domain predicted to adopt a cystatin-like fold. Cathepsin F would therefore be the first cysteine protease zymogen containing a cystatin-like domain.
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Affiliation(s)
- D K Nägler
- Biotechnology Research Institute, National Research Council of Canada, 6100 Avenue Royalmount, Montréal, Québec, H4P 2R2, Canada
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34
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Abstract
The recent advent of gene-targeting techniques in malaria (Plasmodium) parasites provides the means for introducing subtle mutations into their genome. Here, we used the TRAP gene of Plasmodium berghei as a target to test whether an ends-in strategy, i.e., targeting plasmids of the insertion type, may be suitable for subtle mutagenesis. We analyzed the recombinant loci generated by insertion of linear plasmids containing either base-pair substitutions, insertions, or deletions in their targeting sequence. We show that plasmid integration occurs via a double-strand gap repair mechanism. Although sequence heterologies located close (less than 450 bp) to the initial double-strand break (DSB) were often lost during plasmid integration, mutations located 600 bp and farther from the DSB were frequently maintained in the recombinant loci. The short lengths of gene conversion tracts associated with plasmid integration into TRAP suggests that an ends-in strategy may be widely applicable to modify plasmodial genes and perform structure-function analyses of their important products.
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Affiliation(s)
- A Nunes
- Department of Pathology, Kaplan Cancer Center, New York University Medical Center, New York, New York 10016, USA
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35
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Abstract
Cathepsin K is a lysosomal cysteine protease belonging to the papain superfamily. It has been implicated as a major mediator of osteoclastic bone resorption. Wild-type human procathepsin K has been crystallized in a glycosylated and a deglycosylated form. The latter crystals diffract better, to 3.2 A resolution, and contain four molecules in the asymmetric unit. The structure was solved by molecular replacement and refined to an R-factor of 0.194. The N-terminal fragment of the proregion forms a globular domain while the C-terminal segment is extended and shows substantial flexibility. The proregion interacts with the enzyme along the substrate binding groove and along the proregion binding loop (residues Ser138-Asn156). It binds to the active site in the opposite direction to that of natural substrates. The overall binding mode of the proregion to cathepsin K is similar to that observed in cathepsin L, caricain, and cathepsin B, but there are local differences that likely contribute to the specificity of these proregions for their cognate enzymes. The main observed difference is in the position of the short helix alpha3p (67p-75p), which occupies the S' subsites. As in the other proenzymes, the proregion utilizes the S2 subsite for anchoring by placing a leucine side chain there, according to the specificity of cathepsin K toward its substrate.
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Affiliation(s)
- J Sivaraman
- Biotechnology Research Institute, National Research Council of Canada, Montréal, Québec
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36
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Abstract
A novel cDNA encoding a cysteine protease of the papain family named cathepsin X was obtained by PCR amplification from a human ovary cDNA library. The cathepsin X cDNA is ubiquitously expressed in human tissues and contains an open reading frame of 912 nucleotides encoding a predicted protein of 303 amino acids. All highly conserved regions in papain-like cysteine proteases including the catalytic residues are present in cathepsin X. The mature part of cathepsin X is 26-32% identical to human cathepsins B, C, H, K, L, O, S and W. The cathepsin X sequence contains several unique features: (i) a very short proregion; (ii) a three amino acid residue insertion in a highly conserved region between the glutamine of the putative oxyanion hole and the active site cysteine; and (iii) a second insertion of 15 amino acid residues that can be aligned with the occluding loop region in cathepsin B.
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Affiliation(s)
- D K Nägler
- Biotechnology Research Institute, National Research Council of Canada, Montréal, Qué
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37
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Abstract
To demonstrate the usefulness of an engineered papain nitrile hydratase as a biocatalyst, a peptide amidrazone was prepared by incubation of the nitrile MeOCO-Phe-Alanitrile with the Gln19Glu papain mutant in the presence of salicylic hydrazide as a nucleophile. The amidrazone results from nucleophilic attack by salicylic hydrazide at the imino carbon of the thioimidate adduct formed between the enzyme and the peptide nitrile substrate. Compared to wild-type enzyme, the engineered nitrile hydratase causes a better than 4000-fold increase in the rate of amidrazone formation and yields a product of much higher purity. The advantages over other nitrile-hydrolyzing enzymes and current limitations of the papain nitrile hydratase are discussed.
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Affiliation(s)
- E Dufour
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Que
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38
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Ménard R. Malaria transfection: a new tool to study molecular function-reply. Parasitol Today 1998; 14:125. [PMID: 17040722 DOI: 10.1016/s0169-4758(97)01208-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
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39
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Ménard R, Carmona E, Takebe S, Dufour E, Plouffe C, Mason P, Mort JS. Autocatalytic processing of recombinant human procathepsin L. Contribution of both intermolecular and unimolecular events in the processing of procathepsin L in vitro. J Biol Chem 1998; 273:4478-84. [PMID: 9468501 DOI: 10.1074/jbc.273.8.4478] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
The autocatalytic processing of procathepsin L was investigated in vitro using purified recombinant proenzyme expressed in Pichia pastoris. Pure intermolecular processing was studied by incubating the mutant procathepsin L (C25S), which cannot autoactivate with a small amount of mature active cathepsin L. The results clearly establish that, contrary to recent reports, intermolecular processing of procathepsin L is possible. The main cleavage sites are located at or near the N terminus of the mature enzyme, in an accessible portion of the proregion, which contains sequences corresponding to the known substrate specificity of cathepsin L. Contrary to procathepsins B, K, and S, autocatalytic processing of procathepsin L can generate the natural mature form of the enzyme. A continuous assay using the substrate benzyloxycarbonyl-Phe-Arg 4-methylcoumarinyl-7-amide hydrochloride has also been used to obtain information on the nature of the steps involved in the autocatalytic processing of wild-type procathepsin L. Processing is initiated by decreasing the pH from 8.0 to 5.3. The influence of proenzyme concentration on the rate of processing indicates the existence of both unimolecular and bimolecular steps in the mechanism of processing. The nature of the unimolecular event that triggers processing remains elusive. Circular dichroism and fluorescence measurements indicate the absence of large scale conformational change in the structure of procathepsin L on reduction of pH. However, the bimolecular reaction can be attributed to intermolecular processing of the zymogen.
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Affiliation(s)
- R Ménard
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec H4P 2R2, Canada.
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40
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Nägler DK, Storer AC, Portaro FC, Carmona E, Juliano L, Ménard R. Major increase in endopeptidase activity of human cathepsin B upon removal of occluding loop contacts. Biochemistry 1997; 36:12608-15. [PMID: 9376367 DOI: 10.1021/bi971264+] [Citation(s) in RCA: 134] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
The main feature distinguishing cathepsin B from other cysteine proteases of the papain family is the presence of a large insertion loop, termed the occluding loop, which occupies the S' subsites of the enzyme. The loop is held in place mainly by two contacts with the rest of the enzyme, involving residues His110 and Arg116 on the loop that form salt bridges with Asp22 and Asp224, respectively. The influence of this loop on the endopeptidase activity of cathepsin B has been investigated using site-directed mutagenesis and internally quenched fluorogenic (IQF) substrates. Wild-type cathepsin B displays poor activity against the substrates Abz-AFRSAAQ-EDDnp and Abz-QVVAGA-EDDnp as compared to cathepsin L and papain. Appreciable increases in kcat/KM were observed for cathepsin B containing the single mutations D22A, H110A, R116A, and D224A. The highest activity however is observed for mutants where both loop to enzyme contacts are disrupted. For the triple-mutant D22A/H110A/R116A, an optimum kcat/KM value of 12 x 10(5) M-1 s-1 was obtained for hydrolysis of Abz-AFRSAAQ-EDDnp, which corresponds to a 600-fold increase relative to wild-type cathepsin B and approaches the level of activity observed with cathepsin L or papain. By comparison, the mutations have little effect on the hydrolysis of Cbz-FR-MCA. The influence of the mutations on the pH dependency of activity also indicates that the complexity of pH activity profiles normally observed for cathepsin B is related to the presence of the occluding loop. The major increase in endopeptidase activity is attributed to an increase in loop "flexibility" and suggests that the occluding loop might move when an endopeptidase substrate binds to the enzyme. The possible contribution of these interactions in regulating endopeptidase activity and the implications for cathepsin B activity in physiological or pathological conditions are discussed.
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Affiliation(s)
- D K Nägler
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, H4P2R2 Canada
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41
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Nägler DK, Storer AC, Portaro FC, Carmona E, Juliano L, Ménard R. Major increase in endopeptidase activity of human cathepsin B upon removal of occluding loop contacts. Biochemistry 1997. [PMID: 9376367 DOI: 10.1021/bi971264] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The main feature distinguishing cathepsin B from other cysteine proteases of the papain family is the presence of a large insertion loop, termed the occluding loop, which occupies the S' subsites of the enzyme. The loop is held in place mainly by two contacts with the rest of the enzyme, involving residues His110 and Arg116 on the loop that form salt bridges with Asp22 and Asp224, respectively. The influence of this loop on the endopeptidase activity of cathepsin B has been investigated using site-directed mutagenesis and internally quenched fluorogenic (IQF) substrates. Wild-type cathepsin B displays poor activity against the substrates Abz-AFRSAAQ-EDDnp and Abz-QVVAGA-EDDnp as compared to cathepsin L and papain. Appreciable increases in kcat/KM were observed for cathepsin B containing the single mutations D22A, H110A, R116A, and D224A. The highest activity however is observed for mutants where both loop to enzyme contacts are disrupted. For the triple-mutant D22A/H110A/R116A, an optimum kcat/KM value of 12 x 10(5) M-1 s-1 was obtained for hydrolysis of Abz-AFRSAAQ-EDDnp, which corresponds to a 600-fold increase relative to wild-type cathepsin B and approaches the level of activity observed with cathepsin L or papain. By comparison, the mutations have little effect on the hydrolysis of Cbz-FR-MCA. The influence of the mutations on the pH dependency of activity also indicates that the complexity of pH activity profiles normally observed for cathepsin B is related to the presence of the occluding loop. The major increase in endopeptidase activity is attributed to an increase in loop "flexibility" and suggests that the occluding loop might move when an endopeptidase substrate binds to the enzyme. The possible contribution of these interactions in regulating endopeptidase activity and the implications for cathepsin B activity in physiological or pathological conditions are discussed.
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Affiliation(s)
- D K Nägler
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, H4P2R2 Canada
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42
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Abstract
Gene targeting, which permits alteration of a chosen gene in a predetermined way by homologous recombination, is an emerging technology in malaria research. Soon after the development of techniques for stable transformation of red blood cell stages of Plasmodium falciparum and Plasmodium berghei, genes of interest were disrupted in the two species. The main limitations of gene targeting in malaria parasites result from the intracellular growth and slow replication of these parasites. On the other hand, the technology is facilitated by the very high rate of homologous recombination following transformation with targeting constructs (approximately 100%). Here, we describe (i) the vector design and the type of mutation that may be generated in a target locus, (ii) the selection and screening strategies that can be used to identify clones with the desired modification, and (iii) the protocol that was used for disrupting the circumsporozoite protein (CS) and thrombospondin-related anonymous protein (TRAP) genes of P. berghei.
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Affiliation(s)
- R Ménard
- Department of Pathology and Department of Medical and Molecular Parasitology, New York University Medical Center, New York, New York, 10016, USA
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43
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Sultan AA, Thathy V, Frevert U, Robson KJ, Crisanti A, Nussenzweig V, Nussenzweig RS, Ménard R. TRAP is necessary for gliding motility and infectivity of plasmodium sporozoites. Cell 1997; 90:511-22. [PMID: 9267031 DOI: 10.1016/s0092-8674(00)80511-5] [Citation(s) in RCA: 458] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Many protozoans of the phylum Apicomplexa are invasive parasites that exhibit a substrate-dependent gliding motility. Plasmodium (malaria) sporozoites, the stage of the parasite that invades the salivary glands of the mosquito vector and the liver of the vertebrate host, express a surface protein called thrombospondin-related anonymous protein (TRAP) that has homologs in other Apicomplexa. By gene targeting in a rodent Plasmodium, we demonstrate that TRAP is critical for sporozoite infection of the mosquito salivary glands and the rat liver, and is essential for sporozoite gliding motility in vitro. This suggests that in Plasmodium sporozoites, and likely in other Apicomplexa, gliding locomotion and cell invasion have a common molecular basis.
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Affiliation(s)
- A A Sultan
- Department of Pathology, Kaplan Cancer Center, New York University Medical Center, New York 10016, USA
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44
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Ménard R, Sultan AA, Cortes C, Altszuler R, van Dijk MR, Janse CJ, Waters AP, Nussenzweig RS, Nussenzweig V. Circumsporozoite protein is required for development of malaria sporozoites in mosquitoes. Nature 1997; 385:336-40. [PMID: 9002517 DOI: 10.1038/385336a0] [Citation(s) in RCA: 239] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Malaria parasites undergo a sporogonic cycle in the mosquito vector. Sporozoites, the form of the parasite injected into the host during a bloodmeal, develop inside oocysts in the insect midgut, then migrate to and eventually invade the salivary glands. The circumsporozoite protein (CS), one of the major proteins synthesized by salivary gland sporozoites, is a surface-associated molecule which is important in sporozoite infectivity to the host. Here, by gene targeting, we created Plasmodium berghei lines in which the single-copy CS gene was disrupted. The CS(-) and wild-type parasites produced similar numbers of oocysts of comparable size in the mosquito midgut. In the CS(-) oocysts, however, sporozoite formation was profoundly inhibited. CS therefore appears to have a pleiotropic role and to be vital for malaria parasites in both the vector and the host: in mosquitoes, CS is essential for sporozoite development within oocysts, and in the vertebrate host it promotes sporozoite attachment to hepatocytes.
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Affiliation(s)
- R Ménard
- Michael Heidelberger Division of Immunology, Department of Pathology, Kaplan Cancer Center, New York University Medical Center, 10016, USA.
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45
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Coulombe R, Grochulski P, Sivaraman J, Ménard R, Mort JS, Cygler M. Structure of human procathepsin L reveals the molecular basis of inhibition by the prosegment. EMBO J 1996. [DOI: 10.1002/j.1460-2075.1996.tb00934.x] [Citation(s) in RCA: 295] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
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46
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Coulombe R, Grochulski P, Sivaraman J, Ménard R, Mort JS, Cygler M. Structure of human procathepsin L reveals the molecular basis of inhibition by the prosegment. EMBO J 1996; 15:5492-503. [PMID: 8896443 PMCID: PMC452294] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cathepsin L is a member of the papain superfamily of cysteine proteases and, like many other proteases, it is synthesized as an inactive proenzyme. Its prosegment shows little homology to that of procathepsin B, whose structure, the first for a cysteine protease proenzyme, has been determined recently. We report here the 3-D structure of a mutant of human procathepsin L determined at 2.2 A resolution, describe the mode of binding employed by the prosegment and discuss the molecular basis for other possible roles of the prosegment. The N-terminal part of the prosegment is globular and contains three alpha-helices with a small hydrophobic core built around aromatic side chains. This domain packs against a loop on the enzyme's surface, with the aromatic side chain from the prosegment being located in the center of this loop and providing a large contact area. The C-terminal portion of the prosegment assumes an extended conformation and follows along the substrate binding cleft toward the N-terminus of the mature enzyme. The direction of the prosegment in the substrate binding cleft is opposite to that of substrates. The previously described role of the prosegment in the interactions with membranes is supported by the structure of its N-terminal domain. The fold of the prosegment and the mechanism by which it inhibits the enzymatic activity of procathepsin L is similar to that observed in procathepsin B despite differences in length and sequence, suggesting that this mode of inhibition is common to all enzymes from the papain superfamily.
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Affiliation(s)
- R Coulombe
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec
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47
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Abstract
Synthetic peptides derived from the proregion of rat cathepsin B were used to identify functionally important regions and residues for cathepsin B inhibition. Successive 5 amino acid deletions of a 56 amino acid propeptide from both the N- and C-termini has allowed the identification of two regions important for inhibitory activity: the NTTWQ (residues 21p-25p) and CGTVL (42p-46p) regions. Alanine scanning of residues within these two regions indicates that Trp-24p and Cys-42p contribute strongly to inhibition, their replacement by Ala resulting in 160- and 140-fold increases in Ki, respectively.
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Affiliation(s)
- Y Chen
- Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, Canada
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48
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Abstract
Human procathepsin L has been expressed in the yeast Pichia pastoris and its inactive (Cys25Ser) and unglycosylated (Thr110Ala) mutant purified, concentrated to 4 mg/ml, and crystallized by vapor diffusion against solution containing 1.4 M (Na,K)PO4 buffer, pH 7.8. Crystal size was increased by multiple macroseeding. The crystals are orthorhombic, of space group P2 1 2 1 2 1, with cell dimensions of a = 40.2 A, b = 88.4 A, and c = 94.9 A. A 2.2 A native data set was collected using synchrotron radiation. Although molecular replacement solution for the mature portion of the enzyme was easily found, the resulting maps could not be interpreted in the proregion. Heavy-atom derivative search is in progress.
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Affiliation(s)
- R Coulombe
- Protein Engineering Network of Centers of Excellence, Canada
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49
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Carmona E, Dufour E, Plouffe C, Takebe S, Mason P, Mort JS, Ménard R. Potency and selectivity of the cathepsin L propeptide as an inhibitor of cysteine proteases. Biochemistry 1996; 35:8149-57. [PMID: 8679567 DOI: 10.1021/bi952736s] [Citation(s) in RCA: 150] [Impact Index Per Article: 5.4] [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: 02/01/2023]
Abstract
The cathepsin L propeptide (phcl-2) was expressed in Saccharomyces cerevisiae using a human procathepsin L/alpha-factor fusion construct containing a stop codon at position -1 (the C-terminal amino acid of the proregion). Since the yield after purification was very low, the cathepsin L propeptide was also obtained by an alternate procedure through controlled processing of an inactive mutant of procathepsin L (Cys25Ser/Thrl10Ala) expressed in Pichia pastoris, by small amounts of cathepsin L. The peptide resulting from the cleavage of the proenzyme (phcl-1) was then purified by HPLC. The purified propeptides were characterized by N-terminal sequencing and mass spectrometry and correspond to incomplete forms of the proregion (87 and 81 aa for phcl-1 and phcl-2 respectively, compared to 96 aa for the complete cathepsin L propeptide). The two peptides were found to be potent and selective inhibitors of cathepsin L at pH 5.5, with Ki values of 0.088 nM for phcl-1 and 0.66 nM for phcl-2. The Ki for inhibition of cathepsin S was much higher (44.6 nM with phcl-1), and no inhibition of cathepsin B or papain could be detected at up to 1 microM of the propeptide. The inhibitory activity was also found to be strongly pH-dependent. Two synthetic peptides of 75 and 44 aa corresponding to N-terminal truncated versions of the propeptide were also prepared by solid phase synthesis and displayed Ki values of 11 nM and 2900 nM, respectively, against cathepsin L. The data obtained for the 4 propeptide derivatives of various lengths indicate that the first 20 residues in the N-terminal region of the propeptide are more important for inhibition than the C-terminal region which contributes little to the overall inhibitory activity.
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Affiliation(s)
- E Carmona
- Pharmaceutical Biotechnology Sector, Biotechnology Research Institute, National Research Council of Canada, Montreal, Quebec, Canada
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50
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Abstract
Shigella flexneri is a model for the entry of bacterial pathogens into nonphagocytic epithelial cells. On contact with the epithelial cell surface, the Ipa proteins are secreted from the bacterium. The Ipa complex then triggers a reorganization of the host-cell cytoskeleton leading to the formation of membrane ruffles, which engulf the bacterium.
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Affiliation(s)
- R Ménard
- Unité de Pathogénie Microbienne Moléculaire, Institut Pasteur, Paris, France
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