Determination of some nuclear deoxyribonucleases in X-irradiated rat thymocytes.
The spectrum of nuclear nucleases in control and irradiated (4 Gy) thymocytes has been investigated. Using the method of SDS electrophoresis of nuclear proteins in 3H-DNA-polyacrylamide gels a number of polypeptides of MW. 35, 32, 17.7, 17.2 and 16.4 kDa possessing nuclease activity were found. The 35 kDa enzyme is only active in the presence of Ca2+ and Mg2+ ions. In response to cycloheximide injection (3 mg/100 g body weight) and irradiation, we did not detect the 35 kDa nuclease activity. Nucleases of 32, 17.7, 17.2 and 16.4 kDa are active in the presence of Ca2+ ions. The activities of these nucleases increases 60 min after irradiation. These nucleases were also found in the fraction of polydeoxyribonucleotide (PDN).
Seiliev
A A
AA
Central Research Institute of Roentgenology and Radiology, Russian Ministry of Public Health, St. Petersburg.
Zvonareva
N B
NB
Zhivotovsky
B D
BD
Hanson
K P
KP
D000818:Animals; D002118:Calcium / Q000502:physiology; D002467:Cell Nucleus / Q000187:drug effects / Q000201:enzymology*; D002843:Chromatin / Q000528:radiation effects; D003513:Cycloheximide / Q000494:pharmacology; D003851:Deoxyribonucleases / Q000032:analysis* / Q000187:drug effects; D004591:Electrophoresis, Polyacrylamide Gel; D008274:Magnesium / Q000502:physiology; D008297:Male; D008970:Molecular Weight; D009687:Nuclear Proteins / Q000302:isolation & purification; D010779:Photofluorography; D051381:Rats; D013950:Thymus Gland / Q000166:cytology / Q000187:drug effects / Q000201:enzymology / Q000528:radiation effects*
D002843:Chromatin; D009687:Nuclear Proteins; D003513:Cycloheximide; D003851:Deoxyribonucleases; D008274:Magnesium; D002118:Calcium