[Radiolabeling (125I) with high specific activity of the 1-34 N-terminal derivative of bovine parathormone without loss of biological activity].

Radiolabelling of 1-34 N terminal synthetic biological active fragment of bovine parathormone (1-34 bPTH) with high specific activity and without loss of biological activity was studied. Chloramine T and lactoperoxydase methods were used. To assess biological activity of 125I 1-34 bPTH labelled fragment, we use their ability to activate renal cortical adenylate cyclase. Our results show that enzymatic labelling method preserved the biological activity. With the chloramine T method it is possible to keep the biological activity by using DMSO.