Iodogen-catalysed iodination of human calcitonin and Tyr(0)-katacalcin and purification of their mono- and di-iodinated derivatives by chromatofocussing.
Synthetic calcitonin (CT) and Tyr(0)-katacalcin (tKT) were radioiodinated with Iodogen to high specific activity and with high yields. The products of the iodination procedure were chromatographed on Sephadex G-25 to remove unreacted iodide and then separated by chromatofocussing on PBE 94 (pH 9.6-6.0 for CT and pH 7.4-4.0 for tKT). Clear separation between uniodinated peptides and their mono- and di-iodinated derivatives was achieved with specific activities of 1900 and 3800 Ci/mmol for the respective mono- and di-iodinated peptides. Yields were up to 36 and 24% of mono- and di-iodinated CT and 41 and 29% for mono- and di-iodinated tKT. Our results show that Iodogen provides an effective and gentle way to iodinate peptides with high efficiency. Chromatofocussing is a simple, inexpensive and instrumentally undemanding method that can be performed without specialized chromatographic equipment and that should be applicable to a variety of different tracer preparations.
D002116:Calcitonin / Q000138:chemical synthesis / Q000378:metabolism*; D002700:Chloramines; D002850:Chromatography, Gel; D007455:Iodine / Q000138:chemical synthesis*; D007466:Iodophors / Q000138:chemical synthesis*; D007784:Lactoperoxidase; D010446:Peptide Fragments / Q000378:metabolism; D010455:Peptides / Q000302:isolation & purification; D014105:Tosyl Compounds; D014508:Urea / Q000031:analogs & derivatives* / Q000378:metabolism
D002700:Chloramines; D007466:Iodophors; D010446:Peptide Fragments; D010455:Peptides; D014105:Tosyl Compounds; C016300:chloramine-T; C012385:1,3,4,6-tetrachloro-3 alpha,6 alpha-diphenylglycoluril; C037553:katacalcin; D014508:Urea; D002116:Calcitonin; D007455:Iodine; D007784:Lactoperoxidase