DOI: 10.1111/gbi.12112
Scopus记录号: 2-s2.0-84923082504
论文题名: Isotopic discrimination and kinetic parameters of RubisCO from the marine bloom-forming diatom, Skeletonema costatum
作者: Boller A.J. ; Thomas P.J. ; Cavanaugh C.M. ; Scott K.M.
刊名: Geobiology
ISSN: 1472-4677
EISSN: 1472-4669
出版年: 2015
卷: 13, 期: 1 起始页码: 33
结束页码: 43
语种: 英语
Scopus关键词: algal bloom
; amino acid
; carbon dioxide
; diatom
; dinoflagellate
; enzyme activity
; gene expression
; isotopic analysis
; mass balance
; numerical model
; phylogenetics
; physicochemical property
; primary production
; reaction kinetics
; Bacillariophyta
; Chlorophyta
; Cyanobacteria
; Dinophyceae
; Emiliania huxleyi
; Haptophyceae
; Skeletonema costatum
; Spinacia oleracea
; algal protein
; carbon
; ribulosebisphosphate carboxylase
; biological model
; diatom
; enzymology
; genetics
; kinetics
; metabolism
; molecular genetics
; phylogeny
; phytoplankton
; sequence analysis
; Algal Proteins
; Carbon
; Carbon Isotopes
; Diatoms
; Kinetics
; Models, Biological
; Molecular Sequence Data
; Phylogeny
; Phytoplankton
; Ribulose-Bisphosphate Carboxylase
; Sequence Analysis, Protein
Scopus学科分类: Earth and Planetary Sciences: General Earth and Planetary Sciences
; Environmental Science: General Environmental Science
; Agricultural and Biological Sciences: Ecology, Evolution, Behavior and Systematic
英文摘要: The cosmopolitan, bloom-forming diatom, Skeletonema costatum, is a prominent primary producer in coastal oceans, fixing CO2 with ribulose 1,5-bisphosphate carboxylase/oxygenase (RubisCO) that is phylogenetically distinct from terrestrial plant RubisCO. RubisCOs are subdivided into groups based on sequence similarity of their large subunits (IA-ID, II, and III). ID is present in several major oceanic primary producers, including diatoms such as S. costatum, coccolithophores, and some dinoflagellates, and differs substantially in amino acid sequence from the well-studied IB enzymes present in most cyanobacteria and in green algae and plants. Despite this sequence divergence, and differences in isotopic discrimination apparent in other RubisCO enzymes, stable carbon isotope compositions of diatoms and other marine phytoplankton are generally interpreted assuming enzymatic isotopic discrimination similar to spinach RubisCO (IB). To interpret phytoplankton δ13C values, S. costatum RubisCO was characterized via sequence analysis, and measurement of its KCO2 and Vmax, and degree of isotopic discrimination. The sequence of this enzyme placed it among other diatom ID RubisCOs. Michaelis-Menten parameters were similar to other ID enzymes (KCO2 = 48.9 ± 2.8 μm; Vmax = 165.1 ± 6.3 nmol min-1mg-1). However, isotopic discrimination (ε = [12k/13k - 1] × 1000) was low (18.5‰ 17.0-19.9, 95% CI) when compared to IA and IB RubisCOs (22-29‰), though not as low as ID from coccolithophore, Emiliania huxleyi (11.1‰). Variability in ε-values among RubisCOs from primary producers is likely reflected in δ13C values of oceanic biomass. Currently, δ13C variability is ascribed to physical or chemical factors (e.g. illumination, nutrient availability) and physiological responses to these factors (e.g. carbon-concentrating mechanisms). Estimating the importance of these factors from δ13C measurements requires an accurate ε-value, and a mass-balance model using the ε-value for S. costatum RubisCO is presented. Clearly, appropriate ε-values must be included in interpreting δ13C values of environmental samples. © 2014 John Wiley & Sons Ltd. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/85152
Appears in Collections: 影响、适应和脆弱性
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作者单位: Department of Integrative Biology, University of South Florida, Tampa, FL, United States; Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA, United States
Recommended Citation:
Boller A.J.,Thomas P.J.,Cavanaugh C.M.,et al. Isotopic discrimination and kinetic parameters of RubisCO from the marine bloom-forming diatom, Skeletonema costatum[J]. Geobiology,2015-01-01,13(1)