Biopolymers and cell. 2003; 19 (2): 185 - 189

Phosphotransferase activity of IgG preparations from blood serum of humans with lupus erythromatosis pathology

Yu. Ya. Kit, V. A. Kovaleva, V. A. Richter

This article evidences that phosphotransferase activity is associated with IgG fraction from blood serum of humans with lupus erythromatosis pathology. Polyclonal IgG (f. 1) was purified by sequential chromatography on protein-A-sepharose and DEAE-Fractogel. The IgG fraction (f. 2) possessing affinity to ATP was obtained by chromatography of f. 1 on ATP-sepharose. Phosphorylation of f. 1 and f. 2 in the presence of [γ-³²P]ATP caused the formation of ³²P-labeled low-molecular-weight non-protein products detected by SDS-electrophoresis. These products contained ³²P-labeled phospholipids which formed 6 fractions upon separation by the two-dimensional TLC. The IgG polypeptides phosphorylation was not observed. After removal of the lipids by gel-filtration in the buffer containing 5 % dioxan, the phosphorylation of H- and L-chains of IgG has been detected. Addition of 1 μM ATP to the reaction medium containing 0,018 μM [γ-³²P] ATP, increased inclusion of ³²P in the H-chain of IgG. We assume, that IgG-abzymes having phosphotranspherase activity may be present in blood of humans with lupus erythromatosis patology.