Evidence for the production of trioxygen species during antibody-catalyzed chemical modification of antigens

Abstract

Recent work in our laboratory showed that products formed by the antibody-catalyzed water-oxidation pathway can kill bacteria. Dihydrogen peroxide, the end product of this pathway, was found to be necessary, but not sufficient, for the observed efficiency of bacterial killing. The search for further bactericidal agents that might be formed along the pathway led to the recognition of an oxidant that, in its interaction with chemical probes, showed the chemical signature of ozone. Here we report that the antibodycatalyzed water-oxidation process is capable of regioselectively converting antibody-bound benzoic acid into para-hydroxy benzoic acid as well as regioselectively hydroxylating the 4-position of the phenyl ring of a single tryptophan residue located in the antibody molecule. We view the occurrence of these highly selective chemical reactions as evidence for the formation of a shortlived hydroxylating radical species within the antibody molecule. In line with our previously presented hypothesis according to which the singlet-oxygen ( 1 O* 2) induced antibody-catalyzed wateroxidation pathways proceeds via the formation of dihydrogen trioxide (H 2O3), we now consider the possibility that the hydroxylating species might be the hydrotrioxy radical HO 3• , and we point to the remarkable potential of this either H 2O3-or O3-derivable species to act as a masked hydroxyl radical (HO • ) in a biological environment.

Antibody-Dependent Cell-Mediated Cytotoxicity- and Complement-Dependent Cytotoxicity-Independent Bactericidal Activity of an IgG against Pseudomonas aeruginosa O6ad

“…Some cytotoxic Abs to microorganisms or mammalian cells trigger target cell death by DNA or protein hydrolysis (53)(54)(55)(56)(57)(58)(59) or by production of toxic oxidative molecules (i.e., H 2 O 2 , O 3 , and hydroxide radials) via catalyzing water oxidation reactions (13)(14)(15). Our data exclude the possibility that the anti-O6ad Abs exert their bactericidal action through DNase (Supplemental Fig.…”

“…Certain chemical reactions catalyzed by abzymes result in production of toxic byproducts, thereby leading to complement-and immune cellindependent killing of target organisms (12,14,16). For example, Abs with peroxidase activity catalyze the reaction between singlet oxygen (1O 2 *) and water, resulting in the production of oxidative molecules, such as H 2 O 3 , H 2 O 2 , and O 3 (13)(14)(15)(16)(17)(18). These bioreactive oxidants are highly cytotoxic and can destroy target cells or damage tissues (12, 14-16, 19, 20).…”

“…Because the first independent reports on catalytic Abs, also called abzymes (6,7), a number of Abs have been discovered or designed to catalyze many distinct classes of chemical reactions (8)(9)(10)(11)(12)(13)(14)(15). Certain chemical reactions catalyzed by abzymes result in production of toxic byproducts, thereby leading to complement-and immune cellindependent killing of target organisms (12,14,16).…”

Study of Trace Elements in Bioarena System and in in Vivo Conditions

“…Figure 3b summarizes the reaction series supposedly taking into account the earlier and more recent determining observations. [19][20][21][22][23] This complex figure includes two fundamental, related biochemical pathways which can be studied in BioArena system.…”

“…[19,20] 1 O 2 can oxidize water molecules and -among others-ozone can be formed which is an important component of the adaptive immune system ( Figure 3B). [21][22][23] According to preliminary experiments and observations trace elements as carriers transport HCHO molecules in a dose-dependent manner to different points of a given biological unit.…”