Specific tritiation onto C‐2 and C‐5 positions of histidine ‐ containing peptide. Application to thyroliberin

Several synthetic protected peptides have been catalytically exchangelabelled using tritium gas to a level between 0.1 and 12.5 Ci rnmol .High specific activities could be achieved for histidine-containing peptides, and the factors influencing this have been investigated as have the location and stability of the introduced label. L-Cysteinecontaining peptides gave rise to the corresponding peptides containing L-alanine heavily labelled with tritium. The substitution pattern within the alanine residue has been established.-1

Tritiated peptides. Part 14¹. Catalytic exchange labelling of various synthetic peptides

Brundish¹,

Combe²,

Wade³

1983

Enhanced incorporation of nonhydrolyzable tritium in GnRH and TRF by catalytic exchange labeling

Oehlke¹,

Mittag²,

Tóth

et al. 1987

An investigation into the catalytic deuteration and tritiation of dehydroproline⁹‐buserelin

Oehlke

Brankoff²,

Schmidt

et al. 1993

SummaryFor optimizing the catalytic tritiation of peptides, the catalytic deuteration of buserelin and DhPg-buserelin' in DMA and DnO was studied by FAB-MS. The deuteration degrees achieved after reaction of DhPg-buserelin were comparable in both solvents. The nonspecific incorporation of deuterium found after deuteration of buserelin was clearly lower after reaction in DMA. Tritiation of DhPg-buserelin in DMA using 05% tritium gas, with conditions optimized by the deuteration experiments, resulted in a specific radioactivity of 1.3 TBq/mmol. 72 and 13 percent of the incorporated radioactivity were found to be associated with proline and histidine, respectively, after acidic hydrolysis.