Introduction-Interactions of three copper(II) bis(thiosemicarbazone) PET radiopharmaceuticals with human serum albumin, and the serum albumins of four additional mammalian species, were evaluated.

The Cu-PTSM (pyruvaldehyde bis(N 4 -methylthiosemicarbazonato)copper(II)) and Cu-ATSM (diacetyl bis(N 4 -methylthiosemicarbazonato)copper(II)) radiopharmaceuticals exhibit strong, species-dependent binding to human serum albumin (HSA), while Cu-ETS (ethylglyoxal bis(thiosemicarbazonato)copper(II)) appears to only exhibit non-specific binding to human and animal serum albumins. This study examines the structural basis for HSA binding of Cu-PTSM and Cu-ATSM via competition with drugs having known albumin binding sites. Warfarin, furosemide, ibuprofen, phenylbutazone, benzylpenicillin, and cephmandole were added to HSA solutions at drug:HSA mole ratios from 0 to 8:

Introduction-The Cu-PTSM (pyruvaldehyde bis(N 4 -methylthiosemicarbazonato)copper(II)) and Cu-ATSM (diacetyl bis(N 4 -methylthiosemicarbazonato)copper(II)) radiopharmaceuticals exhibit strong, species-dependent binding to the IIA site of human serum albumin (HSA), while the related Cu-ETS (ethylglyoxal bis(thiosemicarbazonato)copper(II)) radiopharmaceutical appears to only exhibit non-specific binding to human and animal serum albumins.