[Properties and quaternary structure of ribulosediphosphate carboxylase from the leaves of Elymus (Psathyrosachys) junceus].

The enzyme ribulosdiphosphate carboxylase was isilated from the leaves of Elymus (Psathyrosachys) junceus. The enzyme was found homogenous during disc-electrophoresis in polyacrylamide gel and analytical ultracentrifugation. The sedimentation coefficient for the enzyme is 17,4S. The enzyme molecular weight as determined by the sedimentation equilibrium technique is equal to 540000. The enzyme molecule consists of 2 types of subunits, i.e. the larger subunit has m.w. of 55000, the smaller one--12900. The number of large subunits is 8, that of small ones--8. The specific activity of the homogenous enzyme makes up to 2,45 mkmoles of CO2 per min per mg of protin (pH 8,0, 30 degrees). The purified enzyme was stable in Mg2+- and dithiothreitol-containing buffers for 3--4 weeks at 4 degrees and for 5--6 months at --20 degrees. The amino acid composition of the enzyme molecule is similar to that of the enzyme from spinach leaves.