Properties of Antigenomic Hepatitis Delta Virus Ribozyme That Consists of Three RNA Oligomer Strands

T. I. Belianko, V. A. Alekseenkova, L. P. Savochkina^*, M. A. Lukin, and R. Sh. Beabealashvilli

Russian Cardiology Research and Development Complex, Russian Academy of Medical Sciences, 3-ya Cherepkovskaya ul. 15a, Moscow 121552, Russia; fax: (7-095) 414-6699; E-mail: lasav@cardio.ru

^* To whom correspondence should be addressed.

Received October 8, 2002; Revision received November 18, 2002

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A three-strand ribozyme, a derivative of antigenomic hepatitis delta virus (HDV) ribozyme, which consists of subfragments of 16 (L), 17 (S), and 33 nucleotides (B), has been constructed. The ternary B-L-S complex formed by the subfragments in stoichiometric ratio was able to catalyze a self-cleavage reaction. Kinetics of this reaction exhibited biphasic behavior and the same parameters as in the case of natural cis-ribozyme. Study of kinetics of reaction initiated by adding various reaction components and the study of binary complex formation between subfragments B and L, B and S, and also ternary B-L-S complex formation revealed that: 1) in the presence of Mg²⁺, B and S form a stoichiometric complex, L and S do not form complex at all, while B and L form 2 types of complexes, probably B-L and 2B-L; and addition of S subfragment prevented the formation of the latter complex; 2) the reaction initiated by S subfragment proceeds much slower than that initiated by other components pointing to the possibility that in the absence of S L may form a nonproductive complex with B, which is slowly displaced by S followed by productive ternary complex formation. Dissociation constants for binary B-L, B-S and ternary B-L-S complexes have been estimated.

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Key words: ribozyme, HDV, subfragments, association, kinetic

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