Isolation of ribosomal subunits from an extremely halophilic archaebacterium Halobacterium halobium by hydrophobic interaction chromatography.

A new method was developed for a simple, rapid, and effective preparation of ribosomal subunits from the extremely halophilic archaebacterium Halobacterium halobium using hydrophobic interaction chromatography on phenyl-Sepharose CL-4B. One milliliter of swollen gel matrix (total bed volume) bound up to 15 A260 units of 70 S ribosomes. By a stepwise reduction of the ionic strength first 50 S and then 30 S subunits were solubilized and differentially eluted. The pooled fractions containing 50 S and 30 S subunits, respectively, were adjusted to higher ionic strength and concentrated by ultrafiltration. The yield of purified (30 S + 50 S) subunits was up to 60% of the input of 70 S ribosomes. Poly(U)-dependent polyphenylalanine synthesis assay demonstrated that the subunits were as active as native 70 S ribosomes. 30 S and 50 S subunits of nonhalophilic Escherichia coli, however, were not isolated separately by the application of this method.