Kallikrein and Renin in the Membrane Fractions of the Rat Kidney.
Abstract
Plasma membrane (PM) and endoplasmic reticulum (ER) enriched fractions were isolated from the homogenized rat kidney. Transmission electron micrographs of PM showed empty vesicles but no granules present in the fraction. Kallikrein activity was detected in the homogenate, in the microsomal and in the PM and ER fractions; it was most enriched in PM fraction. PM-kallikrein released a kinin, cleaved the peptide substrate, S-2266 and a radio-labeled arginine ester. The ester was also hydrolyzed by renal enzymes other than kallikrein. PM-kallikrein was activated by Triton X-100, phospholipase A(2) lysolecithin, and by a peptide, melittin. Melittin (2 microns) was most potent, it increased the activity to 750%. Solubilized PM and ER kallikrein were inhibited by antibody to rat urinary kallikrein, but membrane-bound kallikrein was more resistant to inhibition. The Km of S-2266 was higher with renal than with urinary kallikrein. PM and ER fractions also contained renin. Its activity was enhanced thirty-fold or more by activators of kallikrein, e.g. by phospholipase A(2), lysolecithin and melittin. Low sodium diet increased the activity of kallikrein in the homogenate and in the membrane fraction. This diet increased the activity of renin in the homogenate but not in the membrane fraction.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 23, 1980
- Accession Number
- ADA086135
Entities
People
- Ervin G. Erdos
- Kazutaka Nishimura
- Patrick E. Ward
Organizations
- University of Texas at Austin