[Kinetic method for the determination of sequences of purine and pyrimidine blocks for circular nucleic acids]

We prove that the sequence of purine and pyrimidine blocks can be restored for circular nucleic acids if molecular weight distributions of fragments of various stages of hydrolysis are known. Hydrolysis of nucleic acid is considered as a progressive fragmentation of a "ciphering", an arbitrary circular polymer, monomers of which have weights from 1 to 6 (corresponding to the real number of purines or pyrimidines in the block), while the site of fragmentation is selected at random. The hydrolysis of circular RNA under the action of pancreatic RNase proceeds in accordance with the model of ciphering. Heuristic method for restoration of the monomer sequence in the ciphering based upon some characteristics of molecular weight distributions (such as Sj(m)-number of the fragments with the weight m containing j unbroken bonds) is considered. Uniqueness of restoration of the monomers sequence of the ciphering based upon known set [Sj(m)] is proved.