Renin-like and cathepsin D activities in bovine pineal glands.
Pineal extract is shown to contain both renin-like and cathepsin D activities. Evidence of renin-like activity in the bovine pineal gland was brought by incubation with natural and synthetic renin substrates and by inhibition by pepstatin. Cathepsin D activity was demonstrated by incubation with hemoglobin and synthetic fluorogenic peptide. The separation of both activities was performed by affinity chromatography on a caseinyl-Sepharose gel. The elution of the extract on affinity chromatography allowed to separate the renin-like activity, which is not retained by the gel at acid pH, from cathepsin D activity, which binds to the column at acid pH and is eluted at alkaline pH. The isolated pineal renin-like activity was found higher on tetradecapeptide renin substrate than on angiotensinogen at pH 5.5. The pH dependence of pineal renin-like activity showed two peaks of activity. One broad peak between pH 6 and 8 and one sharp peak at pH 3.5-4. These results demonstrate the existence of renin-like and cathepsin D activities in bovine pineal gland. They suggest moreover that the renin-like activity measured might represent a mixture of at least two different enzymatic activities.
D000808:Angiotensinogen / Q000378:metabolism; D000818:Animals; D002402:Cathepsin D; D002403:Cathepsins / Q000302:isolation & purification / Q000378:metabolism*; D002417:Cattle; D002846:Chromatography, Affinity; D006454:Hemoglobins / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D010870:Pineal Gland / Q000201:enzymology*; D012083:Renin / Q000302:isolation & purification / Q000378:metabolism*; D013154:Spleen / Q000201:enzymology; D013379:Substrate Specificity
D006454:Hemoglobins; D000808:Angiotensinogen; D002403:Cathepsins; D012083:Renin; D002402:Cathepsin D