The fractions of crystalline and amorphous protein preparations from Phaseolus beans were compared. The crystalline proteins were obtained by precipitating the crystals (5°C, 18 h) from acid extracts. The amorphous forms were obtained by isoelectric precipitation of proteins from alkaline extracts. Protein precipitates, supernatants and extracts were fractionated by gel filtration HPLC. Crystalline and amorphous proteins contained two main fractions corresponding to phaseolin and legumin. These fractions represented approximately 64% (amorphous forms) and 89% (crystalline forms) of the total proteins fractionated. The fraction (average MW =101 kDa) was present in protein extracts in large amount (20-33%) was not recovered in precipitates proteins.