Synthesis and high-performance liquid chromatographic purification of tritiated thyrotrophin-releasing hormone-like peptides.
A simple method is presented for the synthesis and RP-HPLC purification of tritium-labelled thyrotrophin-releasing hormone (TRH)-like tripeptides. These peptides differ from TRH (pGlu-His-Pro-amide) in that they possess a neutral or acidic residue in place of the histidine of TRH. The method involves the preparation of the appropriate dipeptide by a solid-phase peptide synthesis procedure using 9-fluorenylmethoxycarbonyl (Fmoc) protection. Very small amounts of tritiated glutamine are then converted into tritiated pyroglutamic acid, and coupling to the dipeptide is effected using a mixed anhydride derived from Fmoc-phenylalanine and the tritiated pyroglutamic acid. The required labelled product is then separated from unlabelled material by reversed-phase HPLC, as the hydrophobicity of the phenylalanine-containing product ensures that it is strongly retained. The availability of a series of tritium-labelled markers prepared by this method has permitted the unequivocal identification of certain naturally occurring TRH-like peptides.
Institute of Endocrinology, Prague, Czech Republic.
R
R
Bílek
A F
AF
Bradbury
D G
DG
Smyth
D000595:Amino Acid Sequence; D000812:Anhydrides / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D002851:Chromatography, High Pressure Liquid; D002852:Chromatography, Ion Exchange; D005973:Glutamine / Q000737:chemistry; D006801:Humans; D007553:Isotope Labeling; D008297:Male; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000138:chemical synthesis* / Q000302:isolation & purification*; D010649:Phenylalanine / Q000737:chemistry; D011467:Prostate / Q000737:chemistry; D011761:Pyrrolidonecarboxylic Acid / Q000737:chemistry; D011863:Radioimmunoassay; D013973:Thyrotropin-Releasing Hormone / Q000138:chemical synthesis* / Q000302:isolation & purification*
D000812:Anhydrides; D010446:Peptide Fragments; D005973:Glutamine; D010649:Phenylalanine; D013973:Thyrotropin-Releasing Hormone; D011761:Pyrrolidonecarboxylic Acid