REQUIREMENTS FOR EXTRACTION OF POLYRIBOSOMES FROM LYOPHILIZED PEEL TISSUE OF CLIMACTERIC PEAR

Profiles of polyribosomes have been obtained from lyophilised peel tissue of climacteric pear (Pyrus communis cv Passe-Crassane) isolated in various buffers. Messenger RNA chains bearing up to 7 ribosomes (heptamers) were resolved and exhibited the highest absorption peak. High vacuolar concentrations of phenolics and acids, which are major obstacles in extracting fruit polyribosomes, were circumvented with the use of polyethylene glycol, insoluble polyvinylpyrrolidone (Polyclar AT), extraction at low temperature and high ionic strength buffer. Addition of Ca2+ to the extracting medium precipitated polysomes but ethyleneglycol bis(2-aminoethylether) tetra-acetic acid (EGTA), a divalent cation chelator with a high affinity for Ca2+, increases the proportion of polyribosomes. © 1979.