Croatica Chemica Acta, Vol. 38 No. 2, 1966.
Original scientific paper
Activation of Ribonuclease I by Gamma Irradiation of 30 S Ribosomes from Escherichia coli
Ž. Kućan
; Institute »Ruder Boskovic«, Zagreb, Croatia, Yugoslavia
Abstract
A sensitive assay. of ribonuclease activity was designed using
polyuridylic acid as a substrate. The amount of the undigested
polyuridylic acid was subsequently determined in a cell-free system
for the polymerization of phenylalanine from Escherichia coli. This
assay was used for the characterization of a nuclease activated by
the irradiation of purified ribosomes from the same bacterium. The
enzyme was identified as ribonuclease I by (1) its location on the
30 S ribosomal subunit, (2) by the absence of mononucleotides in
the products of short incubation, as determined by paper chromatography, and (3) by identification of oligonucleotides as products of such an incubation using chromatography on dextran gel. Activated enzyme sedimented with 30 S ribosomes and exhibited its
activity even at the concentrations of Mg++ which are inhibitory for
the »latent« ribosomal ribonuclease.
Keywords
Hrčak ID:
208170
URI
Publication date:
25.8.1966.
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