The Reduction of Protochlorophyllide into Chlorophyllide. III The phototransformability of the forms of the protochlorophyllide-lipoprotein complex found in Darkness

Three distinct forms of the protochlorophyllide lipoprotein complex are found in darkness within the etiolated leaf: a native form absorbing at 647-648 nm, a transformed, still active 639-640 nm form, and a transformed, denatured 627-628 nm form. Methods for producing the tranformed forms are freezing and thawing, extraction, heat and acid treatments. The significance of these forms is discussed in realtion to the phototransformability of the complex: it is suggested that pigment-pigment interaction is not required for phototransformation while a given binding to the protein is required.