title: [Secondary structure of nuclear precursors of the informational RNA (pre-mRNA)].
abstract: The secondary structure of pre-mRNA species from mouse Ehrlich ascites carcinoma cells extracted with phenol at the temperatures either 55-65 degrees C or 65-85 degrees C was investigated. A fraction of the double helical regions of pre-mRNA was estimated by two methods: a) by recording of melting curves; b) by measuring fluorescence lifetimes of acridine orange dye adsorbed on the nucleic acid. This fraction was about 64-68%. Further lowering of ionic strength down to 0.024 results in 10-15% decrease in the fraction of double regions. Both lowering of ionic strength and increase of the temperature up to 50-55 degrees C results in despiralisation of pre-mRNA regions which contain more than 70% of AU-nucleotide pairs. Only regions containing mainly GC-nucleotide pairs remain double-stranded under heating to temperatures above 50 degrees C. These facts were established on the basis of studies of acriflavin dye complexes with pre-mRNA.
mesh_terms: D000818:Animals; D002286:Carcinoma, Ehrlich Tumor / Q000032:analysis*; D007700:Kinetics; D051379:Mice; D009690:Nucleic Acid Conformation; D009691:Nucleic Acid Denaturation; D012333:RNA, Messenger / Q000096:biosynthesis; D013050:Spectrometry, Fluorescence; D013696:Temperature
chemical_list: D012333:RNA, Messenger
vernacular_title: Izuchenie vtorichnoĭ struktury iadernykh predshestvennikov informatsionnoĭ RNK (pro-mRNK).