Global amount of RuBisCO - most abundant protein on Earth

Value 4e+13 grams
Organism Biosphere
Reference R.J. Ellis, 1979, The most abundant protein in the world, Trends in biochemical sciences 4:241–44 doi:10.1016/0968-0004(79)90212-3 p.241 right column 2nd paragraph
Comments "Calculations of the amount of RuBPCase on the earth are necessarily approximate. The total amount of carbon fixed per year by land plants is estimated to be 50×10^15 g [ref 10, Woodwell, G. M. (1978) Sci. Am. 238, 34-43]. From turnover number of the enzyme it can be shown that the amount of RuBPCase required to fix this quantity of carbon is about 4×10^13 g of protein, or 10^4 g for each person [as of 1979, as of 2015 ~5×10^3g/per person]. The total biomass on the earth has been estimated at 2×10^19 g [ref 11, ‘Energy Resources’ (1973) Open University Second Level Course in Science, p. 120, The Open University Press, Milton Keynes, U.K.]. If it is assumed that 0.1% of this biomass is protein, then the ratio of RuBPCase to total protein is 4×10^13/2×10^16 or 0.2%. The next most abundant protein is probably actin, but no reasonable estimate of its total quantity is possible."
Entered by Uri M
ID 103827