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On the Biochemical Nature of the ‘Sm’ Nucleoplasmic Antigen
Author(s) -
JONSSON J.,
SCHILLING W.,
NORBERG R.
Publication year - 1981
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1981.tb00123.x
Subject(s) - rna , antigen , ribonucleoprotein , rnase p , microbiology and biotechnology , antigenicity , ribonuclease , biology , chemistry , biochemistry , immunology , gene
The nucleoplasmic autoantigen RNP and Sm are of particular interest because of their association with cerium symptoms of mixed connective tissue disease and systemic lupas erythematosus. The RNP is generally thought to be a ribonucleoprotein and there is evidence that its RNA may be single‐Stranded Experiments presented in this report are in support of the concept that the Sm‐antigen may also be an RNA protein. Purified Sm anti‐Sm precipitates were shown to have high RNA contents and treatment Of Sm‐antigen with RNAse in a hypotonic medium strongly reduced its antigenicity. The latter effect indicates that the Sm‐antigen may in contrast to the RNP contain double‐stranded RNA, a possibility also suggested by the finding that the Sm‐antigen in soluble in 2 m LiCl. The Sm‐antigen was found further to differ from RNP in being selectively absorbent on BD‐Sephadex, while RNP remained active in the supernatant. Cytochemical studies Involving stimulation and Inhibition experiments with lectins and RNA polymerase inhibitors showed that the Sm‐antigen was, in distinction to RNP, sensitive to rifampicin but not to α‐amanitine. Tins suggests that the RNAs of the nucleoplasmic antigens may be synthesized by different RNA polymerases.