2Institute of Chemical Biology and Fundamental Medicine, Siberian Division of the Russian Academy of Sciences, pr. Akademika Lavrent'eva 8, 630090 Novosibirsk, Russia
* To whom correspondence should be addressed.
Received October 1, 2007; Revision received February 1, 2008
Immunoglobulins IgG and sIgA actively hydrolyzing histone H1 have been detected on analyzing proteolytic activity of antibodies isolated by chromatography on Protein A-agarose from blood serum of patients with multiple sclerosis and from colostrum of healthy mothers. These antibodies hydrolyze other histones less actively and virtually failed to cleave lysozyme of chicken egg. By gel filtration at acidic pH and subsequent analysis of protease activity of chromatographic fractions, it was shown that IgG and sIgA molecules were responsible for hydrolysis of histone H1. Anti-histone H1 antibodies of IgG and sIgA classes were purified by affinity chromatography on histone H1-Sepharose from catalytically active antibody preparations. The protease activity of anti-histone H1 IgG antibodies was inhibited by serine proteinase inhibitors, whereas anti-histone H1 sIgA antibodies were insensitive to inhibitors of serine, asparagine, and cysteine proteases.
KEY WORDS: antibodies, protabzymes, multiple sclerosis, blood serum, colostrum, proteolytic activity