FIG. 1.

HPLC chromatogram of purified ¹²⁵I-Ang-(1–12) and mAb specificity and cross-reactivity. The human Ang-(1–12) was radiolabeled with Iodine-125 and was purified on C18 column by HPLC. As shown in HPLC chromatogram, (A) the purified radiolabeled ¹²⁵I-Ang-(1–12) peptide fraction was highly pure (≥99% purity) and was used in internalization and metabolism studies. (B) The Protein L column purified mAb shows high specificity for Ang-(1–12) (filled black circle) and does not cross-react with closely related Ang peptides (1,000 and 5,000 fmol) and human angiotensinogen (5,000 and 10,000 fmol) as demonstrated by RIA. Ang, angiotensin; HPLC, high-performance liquid chromatography; mAb, monoclonal antibody.