I. Studies on pyridine dinucleotide transhydrogenase in rat liver mitochondria. II. Identification of the tissue and cellular sites of catabolism of IgM in the rat
The orientation of the transmembrane enzyme, pyridine dinucleotide transhydrogenase, in the inner mitochondrial membrane of rat liver has been determined by evaluating effects of proteases on the integrity of the enzyme in mitoplasts and submitochondrial particles. Following treatment of these membranes with the non-specific protease, proteinase K, antigenic proteolytic products were detected by immunoblot analysis using polyclonal antibody prepared against purified bovine heart enzyme. Information from these proteolysis studies was used to construct a model of the orientation of transhydrogenase in the inner mitochondrial membrane. In this work, I have used the residualizing label, dilactitol-{sup 125}I-tyramine ({asterisk}I-DLT) to identify the tissue and cellular sites of catabolism of the immunoglobulin, IgM. Purified IgM was labeled conventionally with {sup 125}I or with the residualizing label, {asterisk}I-DLT. The circulating half-life of the protein, 2.7 {plus minus} 0.3 days, was the same when measured using either label, indicating that the residualizing label does not affect the kinetics of the protein's catabolism in vivo. At 2.4 or 5.1 days post injection, the liver contained the major fraction of catabolized protein compared to all the other organs in the body. Additionally, following collagenase digestion of the liver, the hepatocytes were shown to be 77% responsible for the catabolism of IgM by the liver. Autoradiography of the liver revealed that the remaining 23% of IgM catabolized by the liver was due to the Kupffer cells.
- Research Organization:
- South Carolina Univ., Columbia, SC (USA)
- OSTI ID:
- 5516526
- Country of Publication:
- United States
- Language:
- English
Similar Records
Synthesis and evaluation of radioactive and fluorescent residualizing labels for identifying sites of plasma protein catabolism
Sites of catabolism of murine monomeric IgA
Related Subjects
550501 -- Metabolism-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINES
ANIMALS
ANTIBODIES
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BETA DECAY RADIOISOTOPES
BIOLOGICAL HALF-LIFE
BIOLOGICAL LOCALIZATION
BODY
CATABOLISM
CELL CONSTITUENTS
CELL MEMBRANES
CHEMICAL REACTIONS
DAYS LIVING RADIOISOTOPES
DECOMPOSITION
DIGESTIVE SYSTEM
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
ENZYMES
GLANDS
GLOBULINS
HYDROXY COMPOUNDS
IMMUNOGLOBULINS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPES
LIVER
MAMMALS
MATHEMATICAL MODELS
MEMBRANES
METABOLISM
MITOCHONDRIA
NUCLEI
ODD-EVEN NUCLEI
ORGANIC COMPOUNDS
ORGANOIDS
ORGANS
OXIDOREDUCTASES
PHENOLS
PROTEINS
PROTEOLYSIS
RADIOISOTOPES
RATS
RODENTS
SYMPATHOMIMETICS
TYRAMINE
VERTEBRATES