Fig 5 - uploaded by Samuil Umansky
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Electropherograms of proteins of thymocyte chromatin
Source publication
Localization of immunogenic tissue-specific proteins in chromatin regions, hypersensitive to endogenous nucleases, has been studied using rabbit antibodies against rat thymus chromatin. It is shown that the first 1-2,5% of the chromatin (calculating on DNA), released by Mg2+-, Mn2+- and Ca2+/Mg2+-dependent nuclear endonucleases are drastically enri...
Context in source publication
Context 1
... data of electro- phoretic analysis of protein composition in these fractions evidence in favour of this suggestion. As it is seen from Figure 5, the fractions under analysis are drastically enriched in nonhistone proteins of middle and high molecular weight. At the same time the histone content in them is negligible. ...
Citations
... We interpreted this to indicate that varia tions in native chromatin structure or composition may be differentially modified during extraction to give rise to nucleo protein complexes of specific CF reactivity. These antigenic chromatin complexes have been reported to be associated with DNase I-sensitive sites (10,11), heterochromatin regions (12), and chromosome scaffold structures (13). Tumor-specific sources for these antigens have included liver (14-17), colon (12, 18), ira nspia niable animal tumors (19), virus-transformed fibroblasts (19), and spontaneously-arising human tumors (20). ...
Salt-precipitated chromatin was prepared from cultured MvlLu line mink lung cells and from these cells transformed by either of the oncogenes v-mos (MIMS-102 line) or v-fes (F3C7 line). Xenoantisera were raised to chromatin from each of the three cell types and cross-tested in microcomplement fixation assays to determine immunospecificity. Chromatin from cells transformed by either v-mos or v-fes revealed antigenic profiles statistically indistinguishable (P less than 0.2 to 0.5) from one another with their respective cross-tested antisera, but did not react significantly with antisera to chromatin from the untransformed parental cell line. Likewise, little cross-reaction was observed with chromatin from the untransformed cells and antisera raised to chromatin from either of the oncogenically transformed lines (P less than 0.001), although each chromatin demonstrated high reactivity with its homologous antiserum preparation. These immunological data are consistent with the observed normal or transformed characteristics for each cell type, including morphology, anchorage-independent growth, and growth in the absence of serum.
