title: Superior immunoreactivity of 125I (Des-Tyr-betaAla)-secretin with rabbit anti-secretin sera compared to 125I-secretin and 125 I-6-Tyrosyl secretin.
abstract: A secretin analogue in which the normal amino acid sequence had been elongated by a (Des-Tyr-betaAla)-residue was studied as tracer for secretin radioimmunoassay. 125I-(DATA)-secretin exhibited superior immunoreactivity with several rabbit anti-secretin sera compared to 125I-6-Tyr-secretin and also to secretin iodinated at its N-terminal histidyl residue. This may be due, at least in part, to higher conformational integrity of the secretin moiety in the 125I-(DATA)-secretin molecule. Thus, at present, 125I-(DATA)-secretin appears to be most suitable as tracer for sensitive secretin radioimmunoassay.
mesh_terms: D000595:Amino Acid Sequence; D000937:Antigen-Antibody Reactions; D011863:Radioimmunoassay; D012633:Secretin / Q000031:analogs & derivatives* / Q000032:analysis / Q000276:immunology*; D013329:Structure-Activity Relationship
chemical_list: D012633:Secretin