Etioplasts Contain a Coupling Factor for Photosynthetic Phosphorylation

Etioplasts Contain a Coupling Factor for Photosynthetic Phosphorylation 

it was necessary to see if mature green-maize chloroplast membranes were coated with 90-A particles. Thylakoids were prepared and examined by negative staining in the electron microscope. On the surface of these membranes, we could see 90 A-particles, similar to those on spinach thylakoids and on maize etioplast membranes. This supported our opinion that the 90-A particles in etioplast membranes are identical to the coupling factor. However, some additional experiments were necessary to demonstrate this. 

Treatment /Ltmol ester formed/ mg chlorophyll/h % of activity of unwashed chloroplasts 

Chloroplast membranes washed with 0.01 M NaCl + 0.15 M EDTA 4.98 22.1 

EDTA-treated chloroplast membranes + 1.1 ml chloroplast NaCl-EDTA extract 14.69 65.1 

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