Activation of kidney prorenin by kidney cathepsin B isozymes

Kidney protein was converted to a form of active renin by kidney cathepsin B isozymes. The three isozymes showed similar catalytic behavior for prorenin. The optimal pH for the activation was in the range of 4.0-5.0 and the reaction was completely inhibited by leupeptin. The molecular weight and the isoelectric point of the activated prorenin were 40,000 and pH 4.9. As a minor product, an activated prorenin having an isoelectric point of 5.2 was also produced.