ABSTRACT
Physical, chemical and biological parameters of HeLa cell cultures, which ensure obtaining standard nuclear material to be used as a source of snRNP and snRNA, have been determined. The secondary structure of U1 snRNA as the result of the conformational studies performed using S1 nuclease, A and T1 ribonuclease and Pb(II) ions, and reproducibility of the results obtained after 6-48 h exposure of the cells to actinomycin D at high concentration permit to accept the proposed method of standardization as satisfactory for investigation into snRNP and snRNA.
Subject(s)
HeLa Cells/cytology , RNA Splicing , RNA, Messenger/physiology , RNA, Small Nuclear/isolation & purification , Base Sequence , Cell Division/physiology , HeLa Cells/chemistry , HeLa Cells/metabolism , Humans , Molecular Sequence Data , Nucleic Acid Conformation , RNA, Small Nuclear/biosynthesis , RNA, Small Nuclear/physiologyABSTRACT
Cytotoxicity of 22 amino acid 4-N-substituted cytosine derivatives was studied on KB and HeLa human tissue cultures. A 4-N-(1H-2-oxo-4 pyrimidyl)-tryptamine with ED50 activity values of 0.145 x 10(-3) mole/l and ED0 = 0.4 x 10(-5) mole/l showed the highest cytotoxic activity and was qualified for further in vivo investigation. The secondary modification of tryptamine substituent seems to be a determining factor of the cytotoxic activity of 4-N-pyrimidinyl amino acids. The activity of the investigated compounds was inversely dependent on their solubility limited by the results of the solubility-activity relationship analysis.
