The Engineering of Recombinant Active Human Prerenin and its Expression in Mammalian and Insect Cells

Abstract

Human renin, an aspartic proteinase, plays an important role in the regulation of the renin angiotensin cascade that regulates blood pressure and electrolyte balance. The cDNA encoding human renin has been cloned and sequenced¹ and is known to encode a 406 amino acid preprorenin protein that is processed by signal peptidase during secretion to release prorenin as a 386 amino acid zymogen. The 46 amino acid “pro” domain can then be removed by a renin processing enzyme to produce enzymatically active renin by cleavage at an Arg-Leu bond. Many investigators have mimicked the effects of the renin processing enzyme by trypsin activation in vitro where high concentrations of trypsin are incubated with prorenin for brief periods of time followed by excess trypsin inhibitor to stop secondary proteolytic processing by trypsin.² We have constructed prerenin by deleting the “pro” segment of the preprorenin cDNA and expressed this construct transiently and stably in mammalian cells and in the baculovirus insect cell expression system.