RIBONUCLEIC ACID-POLYPHOSPHATE FROM ALGAE: III. HYDROLYSIS STUDIES

RNA-polyphosphate was isolated from synchronous Chlorella cells.After each of a series of hydrolytic treatments, RNA-polyphosphatewas chromatographically analyzed by means of a two-column ion-exchangesystem. Alkaline hydrolysates contained primarily ribonu-cleotides,pyrophosphate, and tripolyphosphate. Acid hydrolysates containedribonucleotides, purine bases, ribonucleosides, orthophosphate,and an unknown, inorganic, phosphorus-containing compound (X-P).Treatments with pancreatic ribonuclease, spleen phosphodiesterase,and yeast polyphosphatase left large amounts of RNA-polyphosphatefragments. Treatment with venom phosphodiesterase yielded ahigh molecular weight inorganic polyphosphate fraction freefrom RNA. Such material was hydrolyzed to pyro- and tripolyphosphateby potassium hydroxide, to orthophosphate and an unknown compoundX-P by perchloric acid, and to ortho-, pyro-, and tripolyphosphateby hydroxylamine under ester hydrolysis conditions. Syntheticinorganic polyphosphate was stable to potassium hydroxide andhydroxylamine under the same conditions and yielded only orthophosphateupon perchloric acid hydrolysis. Both natural and syntheticpolyphosphates were hydrolyzed to low molecular weight fragmentsby yeast polyphosphatase. The evidence at present indicatesthat in Chlorella polyphosphate is not a simple phosphate anhydridechain. (Received June 14, 1965; )