Renal cathepsin G and angiotensin II generation.
BACKGROUND
Alternative pathways of angiotensin II biosynthesis play a significant role in the renin-angiotensin system. In this study porcine renal tissue was investigated for angiotensin II-generating enzymes.


RESULTS
Protein extracts from porcine renal tissue were fractionated by liquid chromatography and tested for their angiotensin II-generating activity by the mass-spectrometry-assisted enzyme screening system (MES) and the active fractions were purified to near homogeneity. In one of these active fractions, inhibitable by an angiotensin-converting enzyme specific inhibitor, purified by anion-exchange chromatography, followed by hydroxyapatite chromatography, lectin affinity chromatography, size-exclusion chromatography and two-dimensional electrophoresis, angiotensin-converting enzyme was identified by a tryptic peptide matrix-assisted-laser-desorption/ionization (MALDI) mass fingerprint analysis. In a second active fraction, which was inhibited by chymostatin and antipain, yielded by anion-exchange chromatography, followed by hydroxyapatite chromatography, lectin affinity chromatography, chymostatin-antipain chromatography and one-dimensional electrophoresis, cathepsin G was identified by electro-spray ionization (ESI)-ion-trap mass spectrometry. The angiotensin-generating activities of the fraction containing angiotensin-converting enzyme and the fraction containing cathepsin G were in the same order of magnitude, thus showing that the contribution of cathepsin G towards the production of angiotensin II is significant.


CONCLUSIONS
This is the first time that cathepsin G has been identified in mammalian renal tissue.
Rykl
Jana
J
Internal Medicine - Nephrology, Campus Benjamin Franklin, Berlin.
Thiemann
Joachim
J
Kurzawski
Sandra
S
Pohl
Thomas
T
Gobom
Johan
J
Zidek
Walter
W
Schlüter
Hartmut
H
D000804:Angiotensin II / Q000096:biosynthesis* / Q000302:isolation & purification; D000818:Animals; D000838:Anions; D056649:Cathepsin G; D002403:Cathepsins / Q000096:biosynthesis* / Q000302:isolation & purification; D002852:Chromatography, Ion Exchange; D002853:Chromatography, Liquid; D017886:Durapatite / Q000737:chemistry; D007668:Kidney / Q000201:enzymology*; D037102:Lectins / Q000737:chemistry; D013058:Mass Spectrometry / Q000379:methods; D009842:Oligopeptides / Q000737:chemistry; D012697:Serine Endopeptidases / Q000096:biosynthesis* / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; D013552:Swine
D000838:Anions; D037102:Lectins; D009842:Oligopeptides; D000804:Angiotensin II; C002101:chymostatin; D017886:Durapatite; D002403:Cathepsins; D012697:Serine Endopeptidases; D056649:Cathepsin G