Determination of sulfated peptides by differential iodination.
A sequential approach was developed to label tyrosine sulfate and peptides containing tyrosine sulfate selectively. Amino acids and peptides containing tyrosine and tyrosine sulfate were first iodinated using chloramine-T-method. Reaction products were determined by RP-HPLC. Mono- and biiodination of tyrosine and several model peptides was achieved within 120 s incubation time. Iodination of free tyrosine sulfate and sulfated cholecystokinin26-33 was less than 5%. After desulfation of the reaction products with 1 N HCl successful radioiodination of desulfated tyrosine was carried out whereas tyrosine did incorporate radioactive iodine only 10%. As shown by RP-HPLC specific labeling of tyrosine sulfate containing peptides with 125iodine was achieved.
Niedersächsisches Institut für Peptid-Forschung GmbH, Hannover, Germany.
A G
AG
Schepky
A M
AM
Schmidt
T
T
Schmidt
P
P
Schulz-Knappe
W G
WG
Forssmann
D000595:Amino Acid Sequence; D002700:Chloramines; D002851:Chromatography, High Pressure Liquid; D007202:Indicators and Reagents; D007455:Iodine / Q000737:chemistry*; D007457:Iodine Radioisotopes; D007700:Kinetics; D008969:Molecular Sequence Data; D010455:Peptides / Q000032:analysis*; D012844:Sincalide / Q000031:analogs & derivatives / Q000032:analysis; D013431:Sulfates / Q000032:analysis*; D013462:Sulfur Radioisotopes; D014105:Tosyl Compounds; D014443:Tyrosine / Q000737:chemistry
D002700:Chloramines; D007202:Indicators and Reagents; D007457:Iodine Radioisotopes; D010455:Peptides; D013431:Sulfates; D013462:Sulfur Radioisotopes; D014105:Tosyl Compounds; C016300:chloramine-T; D014443:Tyrosine; C044201:cholecystokinin (26-33); D007455:Iodine; D012844:Sincalide