Über gelöstes lamellares Strukturproteid aus Chloroplasten von Antirrhinum majus

Abstract

Chloroplasts of A. majus strain 50 were treated with water-free formic acid. By formyla-tion of proteins, carbohydrates and lipids they dissolved completely. By fractional precipitation with organic solvents the lamellar structural protein was freed from carbohydrates and lipids. At pH 8-9 the deformylated protein was soluble in buffers below pH 4 and above pH 6. No separation into different fractions occurred in Sephadex and agar gel columns. Electrophoretically it was uniform and sedimented without attendant components with a sedimentation constant of 5.9 s. Sedimentation and diffusion measurements gave an average particle weight of 165,000. The amino-acid composition corresponded closely with those of undissolved lamellar structural proteins of chloroplasts, but with deviations in individual amino acids.