The characterization of the non-histone chromosomal proteins of the main classes of nuclei from rat brain fractionated by zonal centrifugation

Abstract

1. Non-histone chromosomal proteins were isolated from the cell nuclei of whole rat brain and nuclei from different types of brain cells. 2. Brain nuclei were fractionated by zonal centrifugation into five zones deriving from five main categories of brain cells. These are the neuronals, astrocytes I, astrocytes II, oligodendrocytes I and oligodendrocytes II. 3. The non-histone chromosomal proteins were analysed by (a) sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, (b) electrofocusing electrophoresis and (c) two-dimensional electrophoresis. The results of this analysis showed a limited specific pattern of non-histone chromosomal proteins from the different classes of nuclei. Differences were found to exist between the proteins from neuronal and glial nuclei. In particular one polypeptide band with mol.wt. 10000 and pI8.5 was found to be present in the non-histone protein fractions of neuronal nuclei, and absent from the corresponding fractions of nearly all the other classes of nuclei. 4. Two other classes of nuclear proteins, buffered-saline-soluble and 0.35m-NaCl-soluble, were analysed by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis along with the non-histone chromosomal. The similarities and differences among these groups of proteins are discussed. 5. The patterns of non-histone chromosomal proteins during development were investigated by studying them in two age groups of animals: in infant rats (10 days old) and adult rats. The polypeptide that was found to be specific for the proteins of neuronal nuclei of adult rats is present in all the classes of nuclei of infant rats.

Methylation of Chromosomal Proteins in Neuronal and Glial Nuclei Purified from Cerebral Hemispheres of Rat During Postnatal Development

“…Other studies (Heizmann et al, 1980) employing two-dimensional gel electrophoresis and fluorography showed in brain cortex neurons many changes of NHP during development, the majority of which occurred coincidentally with the arrest of cell division and the beginning of differentiation. Qualitative and quantitative changes of NHP patterns in the two nuclear populations have been reported by other authors (Olpe et al, 1973;Tsitilou et al, 1979). It has been suggested (Quick et al,198 1) that methylation of NHP results in the neutralization of negative charges, allowing for the interaction of these proteins with the DNA-histone complex, thus regulating gene expression.…”

Recent progress of surface-enhanced Raman spectroscopy for subcellular compartment analysis

“…and the dynamic changes of their structures and microenvironments during therapeutic processes. Traditional subcellular compartment analytical methods are protein immunoblotting 16 , 17 and gel electrophoresis 18 , 19 , in which the cellular components need to be extracted for further analyses. Mass spectroscopy and deoxyribonucleic acid (DNA) sequencing-based genomics spectrometry 20 are widely applied for the quantitative determinations of specific elements.…”