Tag Archives: proteolytic activity

Proteolytic activity of IgGs from blood serum of wistar rats at experimental rheumatoid arthritis

Yu. Ya. Kit1, S. L. Myronovsky3, I. I. Kril’2,
A. M. Havrylyuk2, V. V. Chop’yak2, R. S. Stoika1

1Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv;
2Danylo Halytsky Lviv National Medical University, Ukraine;
3Ivan Franko National University of Lviv, Ukraine;
e-mail: kit@cellbiol.lviv.ua

The aim of this work was to study the proteolytic activity of IgGs purified from blood serum of Wistar rats at experimental rheumatoid arthritis (ERA) induced by an injection of bovine collagen of type II. Twenty rats were immunized with a preparation of bovine collagen II (Sigma-Aldrich, USA) in the presence of complete Freund’s adjuvant. ERA development was determined by inflammation in limbs of treated animals. IgG preparations were isolated from blood serum of immunized and non-immunized animals by precipitation of antibodies with 33% ammonium sulfate followed by chromatography on the Protein G-Sepharose column. Human histone H1, bovine collagen II, calf thymus histones, myelin basic protein (MBP), bovine serum albumin (BSA), and bovine casein were used as substrates of the proteolytic activity of IgGs. It was found that IgG preparations from blood serum of rats with ERA were capable of cleaving histone H1 and MBP, however, they were catalytically inactive towards collagen II, casein, BSA, and core histones. IgGs from blood serum of non-immunized rats were proteolytically inactive towards all used protein substrates. Thus, we demonstrated that immunization of rats with bovine collagen II induced IgG-antibodies possessing the proteolytic activity towards histone H1 and MBP. This activity might be associated with the development of inflammatory processes in the immunized rats.

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

Yu. Kit1, N. Korniy1,3, I. Kril’2, I. Magorivska1, V. Tkachenko1, R. Bilyy1,2, R. Stoika1

1Institute of Cell Biology, National Academy of Sciences of Ukraine, Lviv;
e-mail: kit@cellbiol.lviv.ua;
2Danylo Galytsky Lviv National Medical University, Ukraine;
3Ivan Franko L’viv National University, Ukraine

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. Histones, myelin basic protein (MBP), lysozyme, BSA, ovalbumin, macroglobulin, casein and cytochrome c served as substrates for determining the proteolytic activity. It was found that IgGs from the blood serum of immunized mice are capable of hydrolyzing histone H1, core histone and MBP. On the contrary, the proteolytic activity of IgGs from the blood serum of not immunized mice was not detected. The absence of proteolytical enzymes in the fraction of IgGs was proven by HPLC chromatography. High levels of proteolytic activity toward histones have been also detected in affinity purified IgGs from blood serum of patients with rheumatoid arthritis, but not in healthy donors. These data indicate that eukaryotic histones may induce production of protabzymes in mammals. The possible origin of these protabzymes and their potential biological role in mammalians is discussed.