Buckley D I, Hagman J, Ramachandran J
Endocrinology. 1981 Jul;109(1):10-6. doi: 10.1210/endo-109-1-10.
The human corticotropin (ACTH) analog, Phe2,Nle4-ACTH-(1-38) was iodinated by the chloramine-T procedure and the product was purified by reverse phase high performance liquid chromatography. The specific radioactivity of [125I]Tyr23,Phe2,Nle4-ACTH-(1-38) was determined by comparing the antiserum binding curves of the iodinated peptide and [3H]ACTH of known specific activity. This method gave a value of 1800 +/- 75 Ci/mmol, which is close to the theoretical radioactivity expected for the introduction of a single 125I atom into the peptide. [125I]Tyr23,Phe2,Nle4-ACTH-(1-38) was as potent as ACTH in stimulating corticosterone production in isolated rat adrenocortical cells. The concentrations for half-maximal steroidogenesis were 36.5 +/- 6.1 pM for the 125I derivative and 37.6 +/- 6.7 pM for ACTH. By the use of this 125I-labeled ligand, a highly sensitive RIA capable of detecting 1 pg aCTH was developed.l The antiserum employed in this study appeared to be directed against residues 11-13 of ACTH.
人促肾上腺皮质激素（ACTH）类似物Phe2，Nle4-ACTH-（1-38）通过氯胺-T法进行碘化，产物通过反相高效液相色谱法纯化。通过比较碘化肽和已知比活性的[3H]ACTH的抗血清结合曲线，测定了[125I]Tyr23，Phe2，Nle4-ACTH-（1-38）的比放射性。该方法得到的值为1800±75 Ci/mmol，这接近于预期向肽中引入单个125I原子的理论放射性。[125I]Tyr23，Phe2，Nle4-ACTH-（1-38）在刺激分离的大鼠肾上腺皮质细胞中皮质酮生成方面与ACTH一样有效。125I衍生物的半数最大类固醇生成浓度为36.5±6.1 pM，ACTH为37.6±6.7 pM。通过使用这种125I标记的配体，开发了一种能够检测1 pg aCTH的高灵敏度放射免疫分析方法。本研究中使用的抗血清似乎针对ACTH的11-13位残基。
