Studies on the compounds of ATP and iron, isolated from human erythrocytes

Factors affecting the adenosine triphosphate induced release of iron from transferrin

“…However, under the weak acidic conditions employed in our study it is possible that ATP formed ATP-iron complexes. The presence of ATP-iron and GTP-iron chelates in red blood cells lends credence to this idea (Bartlett, 1976a,b;Konopka and Szotor, 1972;Konopka et al, 1969). ATP chelates are stable up to pH 8 and have a strong formation constant, i.e.…”

“…Recent studies have concentrated on the effects of small molecular weight chelators and reducing agents directly on transferrin (Carver and Frieden, 1977). Of particular interest are the nucleotides which are present as iron ligands (i.e., adenosine and guanosine triphosphates) in reticulocytes and mature red blood cells (Bartlett, 1976a,b;Goucher and Taylor, 1961;Konopka et al, 1969;Konopka and Szotor, 1972). The chemical properties of the ATP-Fe(III) complex have been investigated (Goucher and Taylor, 1965;Neuberg and Mandl, 1949).…”

Determination of Iron in the Acid-Soluble Fraction of Human Erythrocytes

“…The data of table I seem to indicate that about 50°/o of iron present in the extracts exist in the form of com plexes with ATP. If, as it was suggested by Konopka et al [4], com plexes of ATP with Fe correspond to the formula Fe(ATP)2, then about 20% of total erythrocyte ATP should exist in that form. This value would increase to 30% or more if the proper formula were Fe(ATP)3.…”

“…The results indicate that about 50% of Fe present in the extracts formed complexes with ATP, and the remaining iron was eluted together with AMP, NADP and ADP. Small amounts of Fe added during the preparation of ex tracts were found in fractions of eluate containing AMP, NADP and ADP and slightly influenced the content of iron in the complex with ATP.In a previous paper [4] we found that 20-40°/o of ATP present both in erythrocyte hemolysates and in the whole blood exist in the form of an iron complex. The estimation of Fe in the ATP fraction obtained by the method of Mills and Summers [6] using constant gradient elution with formic acid -ammonium formate system -demonstrated the pres ence of Fe in the descending part of the ATP peak.…”