Iodination of the isolated thyroglobulin (Tg) by peroxidase was compared with various Tg preparations obtained from patients with thyroid diseases. For the purpose, the iodination process was observed in the incubation medium containing Tg, iodide, H2O2-generating system, and thyroid peroxidase (TPO) or lactoperoxidase (LPO). During the incubation, iodination of Tg preparations increased gradua...

Model 3'-azido-3'-deoxynucleosides with thiol or vicinal dithiol substituents at C2' or C5' were synthesized to study reactions postulated to occur during inhibition of ribonucleotide reductases by 2'-azido-2'-deoxynucleotides. Esterification of 5'-(tert-butyldiphenylsilyl)-3'-azido-3'-deoxyadenosine and 3'-azido-3'-deoxythymidine (AZT) with 2,3-S-isopropylidene-2,3-dimercaptopropanoic acid or ...

The synthesis of the title compound is described. Deprotection of Cis(N-Trityl-3-azido-4-Styryl)-2-azetidinone to Cis-(3-azido-4-styryl)-2-azetidinone was found to be accelerated by the special salt effect under acidic condition

1. Crystalline chloroperoxidase is effective in catalyzing the iodination of tyrosine or thyroglobulin when supplemented with HzOz, or with the H20z-generating system, glucoseglucose oxidase. The iodination reaction is very rapid at low concentrations of iodide (5 X 10-5 M), and at low concentrations of tyrosine (1 X 10V4 M) or thyroglobulin (0.33 mg per ml). 2. Iodide is rapidly bound as 3-iod...

Oxidative iodination of human lactoferrin (Lf) as commonly performed by using the chloramine-T, the Iodogen or the lactoperoxidase method produces an unreliable tracer protein because of excessive and heterogeneous polymer formation. Before iodination a minor tetramer fraction may be demonstrable in iron-saturated Lf only. Iodination-induced polymerization of iron-poor as well as iron-saturated...

8-Azidoadenosine 3',5'-cyclic monophosphate (8-azido cAMP) was directly detected in living cells, by applying Cu-free azide-alkyne cycloaddition to probe cAMP derivatives by fluorescence light-up. Fluorescence emission was generated by two non-fluorescent molecules, 8-azido cAMP as a model target and difluorinated cyclooctyne (DIFO) reagent as a probe. The azide-alkyne cycloaddition reaction be...

The human platelet receptors for normal, nonimmune IgG and its F(ab')2 and Fc fragments were studied by the use of a cleavable, bifunctional, photoactivable, 125I-labeled cross-linking agent. Derivatization of the ligands with N-[4-(p-azido-m-[125I]iodophenylazo) benzoyl]-3-aminopropyl-N'-oxysuccinimide ester (Denny-Jaffe reagent) reduced their binding to platelets by greater than or equal to 2...

Viable leucocytes obtained fresh from normal human subjects were shown to be able to catalyse the in vitro iodination of bovine serum albumin (BSA) in a H2O2-generating system. The rate and degree of iodination were greatly improved by sonication of the cells. A balanced salt solution was a more favourable medium than phosphate buffer for the myeloperoxidase (MPO)-catalysed iodination of whole ...

High purity human Lu-thrombin was labeled with “‘Iby lactoperoxidase-catalyzed iodination and was conjugated with the photoreactive reagent N-(4-azido-2nitrophenyl)-2-diaminoethane (NAPEDE) by carbodiimide coupling. Cultured mouse embryo fibroblasts, which respond mitogenically to cu-thrombin, bound the conjugated and unconjugated enzyme similarly, indicating that the NAPEDE group did not signi...