Free thiol groups and labile disulfide bonds in the IgG fraction of human serum
| Autor: | S. Sorger, M. Reiter, Franz Dachs, E. Schauenstein |
|---|---|
| Rok vydání: | 1982 |
| Předmět: |
Male
chemistry.chemical_classification Time Factors Chromatography Chemical Phenomena DTNB Immunology Disulfide bond Dithionitrobenzoic Acid Fraction (chemistry) Chemical Fractionation Chemistry Column chromatography Blood serum chemistry Immunoglobulin G Mole Thiol Humans Immunology and Allergy Female Disulfides Sulfhydryl Compounds Incubation Serum Albumin |
| Zdroj: | Journal of Immunological Methods. 50:51-56 |
| ISSN: | 0022-1759 |
| Popis: | The IgG fraction was isolated from freshly taken blood serum of healthy persons (male and female) by column chromatography on QAE-Sephadex. After 30 min incubation with DTNB (5,5′-dithio-(2,2′-dinitro)-benzoate) the average photometrically determined quantity of thio-anions was 0.24 ± 0.02 SH/mole IgG. Since this result remained unchanged even after 24 h incubation with DTNB, interaction with masked thiol groups cannot be assumed. If, however, the serum was incubated with DTNB for 24 h and the IgG fraction then isolated and treated with thioglycolate, an average of 1.51 ± 0.39 moles of thio-anions were liberated per mole of IgG. This indicates that on 24 h interaction with IgG, DTNB not only reacts with free SH groups, but also opens S-S bonds by a disulfide exchange reaction. The amount of thio-anions resulting from such opened disulfide bonds was calculated as the difference between 1.51 and 0.24, i.e., 0.64 S-S/mole IgG. This would be accounted for if approximately 64% of the IgG fraction is composed of a subfraction containing 1 labile disulfide bond per mole. The average of 1.51 thio-anions per mole IgG resulted from 130 single values with an essentially normal statistical distribution and standard deviation well within the usual biological range. |
| Databáze: | OpenAIRE |
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