PREPARATION OF CYCLIC 2',3'-MONOPHOSPHATES OF OLIGOADENYLATES (A2'P)(N)A-GREATER-THAN-P AND A3'P(A2'P)(N-1)A-GREATER-THAN-P

The action of the guanylyl-preferring RNase from Bacillus intermedius (binase) on a mixture of oligoadenylates with randomly distributed 2'- 5' and 3'-5' internucleotide bonds [(A2'/3'p)(n)] under conditions suf ficient for complete hydrolysis of poly(A) results in a mixture contai ning a single circular oligoadenylate and two series of linear oligoad enylates ending in cyclic 2',3'-phosphate. Individual compounds formed upon digestion of (A2'/3'p)(n) with binase have been isolated. Their structure was determined on the basis of their chemical and enzymatic conversions and confirmed by H-1-,C-13- and P-31-NMR spectra. Accordin g to these data, the circular triadenylate contains one 2'-5' and two 3'-5' internucleotide bonds, linear oligoadenylates of one series cont ain exclusively 2'-5' internucleotide bonds [(A2'p)(n)A>p], while each compound of the other series contains a single 3'-5' internucleotide bond connecting the 5'-ultimate nucleotide residue with the penultimat e one [A3'p(A2'P)(n-1)A>P]. The incubation of compounds of the former series A3'p(A2'p)(n)>p at pH 1.0 and the subsequent action of phosphat ase results in successive formation of compounds of two other new seri es: A3'p(A2'p)(n)A2'(3')p and A3'p(A2'p)(n)A.