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A biphasic nature of the bleomycin‐mediated degradation of DNA
Author(s) -
Strekowski Lucjan,
Mokrosz Jerzy L.,
Wilson W.David
Publication year - 1988
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(88)81023-8
Subject(s) - dithiothreitol , bleomycin , cationic polymerization , ionic strength , chemistry , dna , ferrous , ionic bonding , degradation (telecommunications) , reaction rate constant , biophysics , ion , photochemistry , inorganic chemistry , biochemistry , kinetics , polymer chemistry , enzyme , organic chemistry , biology , genetics , aqueous solution , telecommunications , physics , chemotherapy , quantum mechanics , computer science
The bleomycin‐mediated digestion of DNA in the presence of ferrous ion, molecular oxygen, and dithiothreitol is characterized by a fast initial reaction, which is followed by a much slower process. The fast degradation is due to the fast activation of the bleomycin‐Fe(II) complex and the subsequent fast reaction of the activated complex with DNA. The rate determining step for the slow process is reactivation of the bleomycin‐Fe(III) complex. The apparent rate constants for both reactions increase with increasing ionic strength. The latter, unusual results are interpreted in terms of inhibition of bleomycin turnover by binding of cationic species with DNA at low ionic strength.