Electrophoretic analysis of the ribonucleoproteins of hepatitis delta virus

Replication of hepatitis delta virus (HDV) is dependent on delta antigen (d elta Ag), an HDV-encoded protein, which binds to HDV RNA and is capable of multimerization. To characterize HDV-specific ribonucleoprotein complexes ( RNP) we used electrophoresis into non-denaturing agarose gels followed by n orthern analysis, to detect HDV RNA, and immunoblot, to detect delta Ag. We studied RNP from three sources: (i) vRNP, disrupted virions obtained from infected woodchuck serum; (ii) sRNP, disrupted particles secreted from tran sfected cultured cells; and (iii) cRNP, isolated from cells in which HDV ge nome replication was occurring, sRNP were approximately 28% smaller than vR NP. Treatment of vRNP with aurin tricarboxylic acid disrupted both delta Ag -delta Ag and delta Ag-RNA interactions while vanadyl ribonucleosides relea sed the RNA without causing detectable disruption of the multimeric delta A g complex. cRNP were smaller and more heterogeneous than VRNP and sRNP, and probably contained host components. The application of these electrophoret ic procedures, and especially the use of prior treatments with vanadyl ribo nucleoside complexes have provided valuable information on the RNP of HDV, and we expect they should find applicability in RNP studies of other RNA vi ruses. (C) 1998 Elsevier Science B.V. All rights reserved.