Biomaterial Database

Radioiodination and identification of externally disposed membrane components of Leishmania tropica. 1983

P R Gardiner, and D M Dwyer

Two methods, one involving a lactoperoxidase-glucose oxidase coupled reaction and the other employing the insoluble catalyst 1,3,4,6-tetrachloro-3 alpha, 6-alpha-diphenyl-glycoluril (Iodo-Gen), were used to label the surface membrane of promastigotes of Leishmania tropica major. Both methods labelled approximately 20 proteins or glycoproteins (apparent size range 10 to 110 kDa) in a qualitatively similar manner, however the lactoperoxidase method labelled one additional constituent (260 kDa). By omission of both enzymes, or of Iodo-Gen; by comparison of radioactivity incorporated by particulate and soluble cell fractions; and through the action of proteases on live, labelled promastigotes, the surface-labelling specificity of both procedures was confirmed. Immunoprecipitation of Triton X-100 extracts of labelled cells with rabbit antisera revealed a minimum of twelve (seven major) protein antigens in the homologous system and different but cross-reactive protein species from two other isolates of L. tropica. Lectin precipitation of radiolabelled surface components was possible with concanavalin A (but not with other lectins tested) identifying a minimum of 12 glycoproteins. Two of these glycoproteins (210 and 88 kDa) were not recognized by rabbit antiserum.

UI	MeSH Term	Description	Entries
D007120	Immunochemistry	Field of chemistry that pertains to immunological phenomena and the study of chemical reactions related to antigen stimulation of tissues. It includes physicochemical interactions between antigens and antibodies.
D007457	Iodine Radioisotopes	Unstable isotopes of iodine that decay or disintegrate emitting radiation. I atoms with atomic weights 117-139, except I 127, are radioactive iodine isotopes.	Radioisotopes, Iodine
D007784	Lactoperoxidase	An enzyme derived from cow's milk. It catalyzes the radioiodination of tyrosine and its derivatives and of peptides containing tyrosine.
D007891	Leishmania	A genus of flagellate protozoa comprising several species that are pathogenic for humans. Organisms of this genus have an amastigote and a promastigote stage in their life cycles. As a result of enzymatic studies this single genus has been divided into two subgenera: Leishmania leishmania and Leishmania viannia. Species within the Leishmania leishmania subgenus include: L. aethiopica, L. arabica, L. donovani, L. enrietti, L. gerbilli, L. hertigi, L. infantum, L. major, L. mexicana, and L. tropica. The following species are those that compose the Leishmania viannia subgenus: L. braziliensis, L. guyanensis, L. lainsoni, L. naiffi, and L. shawi.	Leishmania (Leishmania),Leishmania (Viannia),Leishmania leishmania,Leishmania viannia,Leishmania leishmanias,Leishmania viannias,Leishmanias,Leishmanias (Leishmania),Leishmanias (Viannia),leishmanias, Leishmania,viannias, Leishmania
D010447	Peptide Hydrolases	Hydrolases that specifically cleave the peptide bonds found in PROTEINS and PEPTIDES. Examples of sub-subclasses for this group include EXOPEPTIDASES and ENDOPEPTIDASES.	Peptidase,Peptidases,Peptide Hydrolase,Protease,Proteases,Proteinase,Proteinases,Proteolytic Enzyme,Proteolytic Enzymes,Esteroproteases,Enzyme, Proteolytic,Hydrolase, Peptide
D011232	Chemical Precipitation	The formation of a solid in a solution as a result of a chemical reaction or the aggregation of soluble substances into complexes large enough to fall out of solution.	Precipitation, Chemical
D002462	Cell Membrane	The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.	Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia
D001345	Autoradiography	The making of a radiograph of an object or tissue by recording on a photographic plate the radiation emitted by radioactive material within the object. (Dorland, 27th ed)	Radioautography
D037102	Lectins	Proteins that share the common characteristic of binding to carbohydrates. Some ANTIBODIES and carbohydrate-metabolizing proteins (ENZYMES) also bind to carbohydrates, however they are not considered lectins. PLANT LECTINS are carbohydrate-binding proteins that have been primarily identified by their hemagglutinating activity (HEMAGGLUTININS). However, a variety of lectins occur in animal species where they serve diverse array of functions through specific carbohydrate recognition.	Animal Lectin,Animal Lectins,Isolectins,Lectin,Isolectin,Lectin, Animal,Lectins, Animal