Key Points
- To isolate the inactive renin precursor from hog kidney tissue and evaluate its molecular properties and proteolytic activation mechanisms.
- Purified inactive renin from hog kidney extract via affinity chromatography on pepstatin-aminohexyl-Sepharose and Affi-Gel Blue columns.
- Determined molecular weights and binding capacity before and after proteolytic digestion using Ultrogel AcA 44 gel filtration and renin-binding protein assays.
- Inactive renin had a molecular weight of 43,000 ± 1500 Da, which decreased to 41,000 ± 1400 Da following activation with trypsin.
- Trypsin-activated renin bound renin-binding protein to form high-molecular-weight renin, whereas the inactive precursor lacked binding capability.
- Activation by trypsin and chymotrypsin altered the enzyme's net charge, shifting isoelectric points from pH 5.3 in the native precursor to pH 5.1 and pH 4.8, respectively.
Structured PICO
PPopulationHog kidney extract (inactive renin precursor)
IInterventionActivation with proteolytic enzymes (trypsin or chymotrypsin)
CComparatorNative inactive renin
OOutcomeMolecular weight and binding ability of reninsurrogate
This study characterizes the biochemical properties and activation mechanism of a renin precursor isolated from hog kidney.