Crystalline fraction I protein: preparation in large yield

Abolut 1 milligram of twice-recrystallized fraction I protein of constant specific ribulose diphosphate carboxylase activity per gram of leaves (fresh weight) has been obtained from each of seven different species of Nicotiana and 14 reciprocal, interspecific F(1) hybrids. Crystals are produced from honmogenates that have only been centrifuged to remove particulate matter.