Open AccessSimplified method for purification of ribonuclease H from calf thymus.
Author(s) -
Jannis G. Stavrianopoulos,
Erwin Chargaff
Publication year - 1978
Publication title -
proceedings of the national academy of sciences of the united states of america
Language(s) - English
Resource type - Journals
eISSN - 1091-6490
pISSN - 0027-8424
DOI - 10.1073/pnas.75.9.4140
Subject(s) - ribonuclease , rna , molecular mass , sodium dodecyl sulfate , size exclusion chromatography , nuclease , chemistry , isoelectric point , gel electrophoresis , divalent , isoelectric focusing , dna , biochemistry , polyacrylamide gel electrophoresis , nucleotide , enzyme , chromatography , microbiology and biotechnology , biology , gene , organic chemistry
An improved purification procedure for the isolation of ribonuclease H(hybrid nuclease; RNA-DNA-hybrid ribonucleotidohydrolase, EC 3.1.4.34) from the thymus of 4-to 6-months-old calves yields two highly active forms of the enzyme, designated as ribonuclease H1 and H2. Their isoelectric points are 5.0 +/- 0.05 and 5.25 +/- 0.05, respectively; their molecular weight, estimated from gel filtration, is in both cases 64,000 +/- 2000. On sodium dodecyl sulfate gel electrophoresis, two principal bands were identified, with molecular weights of 32,000 and 21,000. The nature of the nucleotides at the 3'-OH terminals, produced initially by the enzymic hydrolysis of hybridized RNA, was examined and shown to be a function of the divalent metal ion employed as activator.