Stimulatory effect of phosphate, ATP and ADP on iron transfer from Fe(III)-bleomycin to apotransferrin.
1. The rate of ferric ion transfer from Fe(III)-bleomycin to apotransferrin was increased in the presence of orthophosphate, ATP and ADP, while AMP was without effect. 2. Ortho phosphate activation probably involves formation of a Fe(III)-bleomycin-phosphate complex. The optical absorption of Fe(III)-bleomycin at 450 nm is enhanced in the presence of phosphate. 3. ATP and ADP remove the ferric ion from the iron-drug complex; thus making the ferric ion readily available for uptake by apotransferrin. 4. Low concentrations of ATP, ADP and AMP, also enhance the 450 nm absorption of the iron-drug complex. Higher ATP and ADP concentrations reduce both the 450 and 384 nm absorption of Fe(III)-bleomycin.
Løvstad
R A
RA
Institute of Medical Biochemistry, University of Oslo, Norway.
D000244:Adenosine Diphosphate / Q000494:pharmacology*; D000249:Adenosine Monophosphate / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000494:pharmacology*; D001059:Apoproteins / Q000378:metabolism*; D001761:Bleomycin / Q000378:metabolism* / Q000031:analogs & derivatives; D007501:Iron / Q000378:metabolism*; D010710:Phosphates / Q000494:pharmacology*; D014168:Transferrin / Q000378:metabolism*
D001059:Apoproteins; D010710:Phosphates; D014168:Transferrin; C028284:apotransferrin; C023503:iron bleomycin; D001761:Bleomycin; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; D000255:Adenosine Triphosphate; D007501:Iron