Structure-activity relationships of atrial natriuretic factor (ANF). III. Correlation of receptor affinity with relative potency on aldosterone production in zona glomerulosa cells.

The activity of various fragments of ANF as inhibitors of aldosterone secretion and as competitors of [125I] ANF (Arg101-Tyr126) binding to specific receptors was studied in bovine zona glomerulosa. Shortening or lengthening the N-terminal segment of ANF does not alter its biological activity while minimally altering affinity for its receptor. Removal of the C-terminal to Cys121 or expansion up to Arg128 leads to 1000-fold decrease in receptor affinity and activity. The results indicate the importance of the C-terminal segment of ANF in determining its active conformation.