[Proteolytic activity of IgG-antibodies of mice, immunized by calf thymus histones].

The main goal of the study was to determine the ability of histones to induce production of the proteolytically active IgG-antibodies in BALB/c mice. In order to perform this study 8 mice were immunized with the fraction of total calf thymus histones. IgGs were isolated from the serum of the immunized and not immunized animals by means of precipitation with 33% ammonium sulfate, followed by affinity chromatography on protein G-Sepharose column.

[Proteolytic activity of blood serum IgG in patients with systemic lupus erythematosis].

Proteolytic activity of blood serum IgGs of 10 patients with systemic lupus erythematosis (SLE) was studied in comparison with such activity in 10 clinically healthy donors. Antibodies were precipitated from blood serum by saturation with 50% (NH4)2SO4 and IgG was isolated by the affinity chromatography on protein G-sepharose column. Histone H1 and core histones from the calf thymus, bovine myelin basic protein (MBP), lysozyme of chicken egg and bovine serum albumin (BSA) were used as substrates for proteolytic action.