Cytosolic pyruvate kinase from endosperm of germinating castor beans (Ricinus communis L.; cv Hale) has been purified 3100-fold to apparent homogeneity and a final specific activity of 203 micromole pyruvate produced/minute per milligram protein. Purification steps included: heat treatment, polyethylene glycol fractionation, Q-Sepharose, ADP-agarose, Mono-Q and Phenyl Superose chromatography. N...

The methyl groups of choline which have been shown to be donated in various reactions in animal metabolism (1, 2) have not been demonstrated to participate in plant methylation reactions. Experiments by Matchett, Kirkwood, and Marion (3, 4), Dubeck and Kirkwood (5), and Sribney and Kirkwood (6), with Hordeum distichum, Ricinus communis, and Dice&a hybrids in which choline was supplied as a poss...

Ricin is a heterodimeric plant protein that is potently toxic to mammalian and many other eukaryotic cells. It is synthesized and stored in the endosperm cells of maturing Ricinus communis seeds (castor beans). The ricin family has two major members, both, lectins, collectively known as Ricinus communis agglutinin ll (ricin) and Ricinus communis agglutinin l (RCA). These proteins are stored in ...

composed of all the valence electrons of the specimen. In this case, the electrons of the metal are coupled via the photon gas; their actions are not completely independent. Such a situation is not the case in the usual photosynthetic system; equilibrium or quasiequilibrium ideas may not be applied. In this situation each photosynthetic event is completely independent of the other events taking...