Analysis of inactive renin by renin profragment monoclonal antibodies

Abstract Two peptides were synthesized, corresponding to the sequences (−19 to −7) and (−26 to −17) of the prorenin prosegment. Monoclonal antibodies were raised to these sequences and used to characterize human plasma inactive renin. Only anti (−19 to −7) reacted with inactive renin, as measured by direct assay or affinity chromatography. The data were used to evaluate two possible inactive renin stuctures: (i) plasma inactive renin is a truncated prorenin lacking the prosegment N-terminal portion; (ii) its spatial conformation masks the N-terminal extremity, preventing interaction of this region with specific antibodies.