Degradation of C3a anaphylatoxins by rat mast cells

Journal Article · Thu May 01 04:00:00 EDT 1986 · Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States)

OSTI ID:7188949

Fukuoka, Y; Hugli, T E

Incubation of /sup 125/I-human C3a with rat peritoneal mast cells (RMC) causes extensive degradation of the ligand. Both cell-bound and free /sup 125/I-C3a (hu) was degraded by RMC, even at 0/sup 0/C, based on SDS-PAGE analysis. The authors examined several protease inhibitors for their ability to prevent degradation of /sup 125/I-C3a (hu). Degradation of /sup 125/I-C3a (hu) by RMC was not inhibited by leupeptin, antipain, elastatinal, pepstatin, ..cap alpha../sub 1/-antitrypsin or EDTA. TPCK and TLCK were only partially effective. PMSF, chymostatin and SBTI were most effective in preventing /sup 125/I-C3a (hu) degradation. These latter compounds are effective inhibitors of the chymotrypsin-like enzyme chymase extracted from RMC, as is TPCK, based on hydrolysis of the substrate BTEE. Degradation of cell-bound ligand is totally prevented only by PMSF (or DFP). Therefore, /sup 125/I-C3a (hu) bound to the RMC appears to be degraded predominantly by chymase; however the cell-bound ligand is attacked by other surface proteases. Degradation of rat C3a by RMC was examined. After incubation with RMC, cell-bound and free /sup 125/I-C3a (rat) showed no evidence of degradation with or without inhibitors present. From these results, the authors conclude that chymase may not play a significant role in regulating anaphylatoxin activity. Furthermore, the authors propose that rat C3a is a preferred ligand for identifying receptors on mast cells because of its resistance to proteolysis.

• Research Organization: Scripps Clinic and Research Foundation, La Jolla, CA
• OSTI ID: 7188949
• Report Number(s): CONF-8606151-
• Journal Information: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States), Journal Name: Fed. Proc., Fed. Am. Soc. Exp. Biol.; (United States) Vol. 45:6; ISSN FEPRA
• Country of Publication: United States
• Language: English

Related Subjects

550501* -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ANIMAL CELLS
ANIMALS
ANTIGENS
BETA DECAY RADIOISOTOPES
COMPLEMENT
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
LIGANDS
MAMMALS
MAST CELLS
MATERIALS
MEMBRANE PROTEINS
METABOLISM
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
PROTEINS
RADIOISOTOPES
RATS
RECEPTORS
RESPONSE MODIFYING FACTORS
RODENTS
SOMATIC CELLS
TOXIC MATERIALS
TOXINS
TRACER TECHNIQUES
VERTEBRATES