Iodinated derivatives of adrenocorticotropic hormone (ACTH) were prepared with the use of NaI and chloramine-T and isolated by isoelectric focusing. The monoiodinated derivative (p1 7.6) was resolved into [monoiodoTyr2]ACTH and [monoiodoTyrZ3]ACTH by chromatography on columns of carboxymethylcellulose. Both monoiodo-AC’IH species exhibited only 30% of the maximum hormonal activity when assayed ...

Sindbis virus was iodinated by using the enzyme lactoperoxidase, an iodination technique which labels only surface proteins. By this technique, the two viral glycoproteins are labeled, and the internal viral protein is not. The two glycoproteins are iodinated to strikingly different extents. This difference in susceptibility to iodination apparently is due to the position or conformation of the...

Brucella abortus releases two components (fractions 3b and 10) that inhibit the myeloperoxidase-H2O2-halide antibacterial system of bovine neutrophils by inhibiting degranulation. Fractions 3b and 10 were analyzed by high-performance liquid chromatography and thin-layer chromotography and compared with nucleotide and base standards. These investigations indicated that fraction 3b coeluted and c...

Surface-exposed proteins of vinblastine-sensitive human lymphoid cell line of leukemic origin (CCRF-CEM) were exam ined by the lactoperoxidase-catalyzed iodination and two-di mensional polyacrylamide gel electrophoresis methods. Spots which comigrate with bovine brain tubulin and rabbit muscle actin were prominently labeled in the whole membrane but not in the high-speed supernatant fraction of...

The contribution of hydrogen peroxide (H2O2) and one of its unstable intermediates, superoxide anion (O2), to the oxidative reactions that occur in phagocytizing leukocytes was explored by depleting these cells of O2. This was accomplished by allowing them to phagocytize latex particles coated with superoxide dismutase (SOD), which catalyzes the generation of H2O2 from O2. Although the rate and...

BACKGROUND Negatively-charged polyhedral boron clusters can be easily halogenated with highly stable boron-halogen bonds and are promising in radionuclide diagnostics and cancer therapy. MATERIALS AND METHODS The radio-iodination conditions for the closo-dodecaborate anion and for the conjugation of its labeled isothiocyanatobenzylammonio derivative to the monoclonal antibody (mAb) were optim...

Insulin receptors of Fao hepatoma cells were labelled with a 125I-labelled photoreactive insulin analogue or by surface iodination catalysed by lactoperoxidase. Cells were then incubated at 37 degrees C, and the cellular localization of the labelled receptors was assessed by limited exposure of intact cells to trypsin. The results show that: (1) photolabelled insulin-receptor complexes are inte...