%0 Journal Article %A Brouwer, Johan %A Warnaar, Sven O. %T Analysis of the Origin of Charge Heterogeneity of Rauscher Murine Leukaemia Virus p30 %D 1980 %J Journal of General Virology, %V 51 %N 2 %P 409-414 %@ 1465-2099 %R https://doi.org/10.1099/0022-1317-51-2-409 %I Microbiology Society, %X SUMMARY Preparations of the 30 × 103 mol. wt. protein (p30) of Rauscher murine leukaemia virus (R-MuLV) which had been purified to homogeneity as judged by gel electrophoresis in the presence of SDS and by amino-terminal amino acid analysis, showed considerable isoelectric heterogeneity. It was found that R-MuLV p30 polypeptide chains are easily converted in vitro into chains with more acidic isoelectric points. R-MuLV p30 polypeptides with different isoelectric points displayed the same set of 125I-labelled tryptic peptides. It is concluded that the charge heterogeneity of R-MuLV p30, as revealed in isoelectric focusing experiments, is not caused by genetic heterogeneity of the virus genome but by post-translational modification. %U https://www.microbiologyresearch.org/content/journal/jgv/10.1099/0022-1317-51-2-409