Degradation of human anaphylatoxin C3a by rat peritoneal mast cells: a role for the secretory granule enzyme chymase and heparin proteoglycan

Thesis/Dissertation · Wed Jan 01 04:00:00 EST 1986

OSTI ID:6548516

Gervasoni, Jr, J E

Purified human C3a was iodinated (/sup 125/I-C3a) and used to study the interaction of labeled peptide with rat peritoneal mast cells (RMC). Cellular binding of /sup 125/I-C3a occurred within 30 sec, followed by a rapid dissociation from the cell. Both the binding of /sup 125/I-C3a and the rate of dissociation from the cell were temperature dependent. At 0/sup 0/C, the binding of /sup 125/I-C3a was increased and the rate of dissociation reduced, as compared to 37/sup 0/C. Once /sup 125/I-C3a was exposed to RMC, it lost the ability to rebind to a second batch of RMC. Analysis of the supernatants by trichloroacetic acid (TCA) precipitation and electrophoresis in sodium dodecyl sulfate polyacrylamide gels (SDS PAGE) revealed a decrease in the fraction of /sup 125/I precipitable by TCA and the appearance of /sup 125/I-C3a cleavage fragments. Pretreatment of RMC with enzyme inhibitors specific for chymotrypsin, but not trypsin, abrogated the degradation of /sup 125/I-C3a. Treatment of RMC bearing /sup 125/I-C3a with Bis (sulfosuccinimidyl) suberate (BS/sup 3/) covalently crosslinked the /sup 125/I-Ca to chymase, the predominant enzyme found in the secretory granules. Indirect immunofluorescence of RMC using the IgG fraction of goat anti-rat chymase showed that chymase is present on the surface of unstimulated cells. The results indicate that /sup 125/I-C3a binds to RMC and is promptly degraded by chymase in the presence of heparin proteoglycan. In addition, this proteolysis of /sup 125/I-C3a by chymase must be blocked in order to detect plasma membrane C3a binding components on RMC.

• Research Organization: Virginia Commonwealth Univ., Richmond (USA)
• OSTI ID: 6548516
• Country of Publication: United States
• Language: English

Related Subjects

550601* -- Medicine-- Unsealed Radionuclides in Diagnostics
62 RADIOLOGY AND NUCLEAR MEDICINE
AMINES
ANIMAL CELLS
ANIMALS
ANTICOAGULANTS
ANTIGENS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BIODEGRADATION
CARBOHYDRATES
CHEMICAL REACTIONS
CONFIGURATION INTERACTION
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ELECTROPHORESIS
ENZYMES
GLUCOPROTEINS
HALOGENATION
HEMATOLOGIC AGENTS
HEPARIN
HYDROLASES
INTERMEDIATE MASS NUCLEI
IODINATION
IODINE 125
IODINE ISOTOPES
ISOTOPES
LABELLED COMPOUNDS
MAMMALS
MAST CELLS
MATERIALS
MEMBRANES
MUCOPOLYSACCHARIDES
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANIC SULFUR COMPOUNDS
PEPTIDE HYDROLASES
PERITONEUM
POLYSACCHARIDES
PROTEINS
RADIOISOTOPES
RATS
RODENTS
SACCHARIDES
SECRETION
SEROUS MEMBRANES
SOMATIC CELLS
TOXIC MATERIALS
TOXINS
VERTEBRATES