Alkylhydroxybenzenes modify immune complex size

Abstract

Alkylhydroxybenzenes (AHBs) are a large group ofbiologically active substances of microbial and plantorigin that are capable of nonspecific interaction withdifferent biopolymers [1–7]. AHB homologues differin the length of the alkyl radical, which determines thedegree of hydrophobicity of the molecules and theirreactivity [1, 2]. The functioning of AHBs as “chemical chaperones” [3, 4] determines the development ofeffects in different systems. For example, changes inthe presence of micromolar concentrations of AHBswere shown for the catalytic activity of some enzymes[3, 4], the physicochemical properties of DNA [5],and the antigenbinding ability and functional activityof antibodies [6, 7]. It was also shown that the molecular weight and sizes of proteins modified with AHBsaltered [3]. However, information about the effect ofAHB on the dimensional characteristics of immunecomplexes is missing.MATERIALS AND METHODSSuspensions of model immune complexes wereformed from purified tetanus toxoid (400 EU/mL) andhuman antitetanus γglobulin containing not less than95% IgG of the total concentration (10%) of protein inthe sample. The study was performed at antigen/antibody ratios of 1 : 32/1 : 8, 1 : 16/1 : 2, 1 : 32/1 : 2, and1 : 64/1 : 2. We used chemical analogues of microbialAHBs (99.9% purity) differing by the length of thealkyl radical: C