학술논문
Association of a polyuridylate-specific endoribonuclease with small nuclear ribonucleo-proteins which had been isolated by affinity chromatography using antibodies from a patient with systemic lupus crythematosus.
Document Type
Article
Author
Source
Subject
*SYSTEMIC lupus erythematosus
*IMMUNOGLOBULINS
*SEPHAROSE
*AFFINITY chromatography
*DEOXYRIBONUCLEOTIDES
*TRANSFER RNA
*DOUBLE-stranded RNA
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Language
ISSN
0014-2956
Abstract
Immunoglobulins, containing antibodies against U1-sn RNP, have been prepared from a patient with systemic lupus erythematosus. After coupling there antibodies to a Sepharose matrix, U-snRNPs have been isolated and purified from rat liver nuclei by use of immunoaffinity chromatography. The resulting RNPs had the typical protein pattern of U-snRNPs and a sedimentation coefficient of 12S. The U-snRNP preparation was associated with an endoribonuclease which required Mg2+ for optimal activity. The enzyme, with an pH optimum of 6.2, degraded only poly(U). Other single-stranded polyribo- and polydeoxyribonucleotides, tRNA, as well as double-stranded RNA and DNA were not digested. The products of a terminal digestion are (U)6–12 with 3′-OH and 5′-P termini. The possible involvement of this endoribonuclease in the splicing of hnRNA is discussed. [ABSTRACT FROM AUTHOR]