Measurement of the rate of copper(II) exchange for Cu-64 complexes of bifunctional chelators

作者：Maheshwari Vidhi; Dearling Jason L J; Treves S Ted; Packard Alan B^*

来源：Inorganica Chimica Acta, 2012, 393: 318-323.

DOI：10.1016/j.ica.2012.07.012

• Bifunctional chelators
• Copper-64
• Stability studies

Measurement of the rate of loss of Cu-64 from the chelators used in the preparation of Cu-64-labeled proteins is critical to the development of effective Cu-64-labeled radiopharmaceuticals. Typically, however, this assessment has been made indirectly, by comparison of the relative uptake of the labeled proteins in the liver, or under non-physiological conditions such as hot 5 M HCl. In the present study, we measured the rate of loss of Cu-64 from a series of chelators (DOTA, TETA, and NOTA) that are commonly used to label proteins as a function of [Cu2+] (1, 2, and 5 mu M) and pH (7.5, 6.0. and 5.0). We found that Cu-64-NOTA is somewhat more kinetically stable than Cu-64-TETA and that both Cu-64-NOTA and Cu-64-TETA are much more kinetically stable than Cu-64-DOTA. Furthermore, the rate of loss of Cu-64 from Cu-DOTA increased with higher [Cu2+] and pH while the rate of loss of Cu-64 from Cu-TETA and Cu-NOTA was minimally dependent on [Cu2+] and pH. These results suggest that NOTA is preferable to TETA and DOTA for the preparation of Cu-64-labeled proteins.

• 出版日期2012-12-1