The modification of nucleosides and nucleotides: IV. The reaction of semicarbazide with nucleic acids

摘要: Abstract 1. Cytidine residues of yeast RNA have been specifically converted into semicarbazide derivatives without altering any other bases. In this reaction the C-4 amino groups cytidine were a semicarbazido group. 2. tRNA modified with was completely hydrolysed to nucleoside 5′-phosphate snake venom phosphodiesterase (orthophosphoric diester phosphohydrolase, EC 3.1.4.1). The base composition estimated after separation nucleotides by ion-exchange column chromatography. A quantitative estimation in achieved method. 3. results sedimentation analysis and gel filtration indicated that no splitting internucleotide bonds occurred during reaction. 4. temperature-absorbance relationship plotted for secondary structure decreased increasing extent modification. 5. rate modification is low when cytosine are highly hydrogen bonded (double-stranded DNA). 6. simple method estimating nucleic acids proposed. procedure specific light absorption 4-deamino-4-semicarbazidocytidine residue range 300–340 mμ at pH 13 followed.