No abstract

The problem of resistance to antibiotics requires the development of new classes of broad-spectrum antimicrobial drugs. The concept of pro-drugs allows researchers to look for new approaches to obtain effective drugs with improved pharmacokinetic and pharmacodynamic properties. Thiosulfinates, formed enzymatically from amino acid sulfoxides upon crushing cells of genus Allium plants, are known as antimicrobial compounds. The instability and high reactivity of thiosulfinates complicate their use as individual antimicrobial compounds. We propose a pharmacologically complementary pair: an amino acid sulfoxide pro-drug and vitamin B6 – dependent methionine γ-lyase, which metabolizes it in the patient’s body. The enzyme catalyzes the γ- and β-elimination reactions of sulfoxides, analogues of L-methionine and L-cysteine, which leads to the formation of thiosulfinates. In the present work, we cloned the enzyme gene from Clostridium sporogenes. Ionic and tautomeric forms of the internal aldimine were determined by lognormal deconvolution of the holoenzyme spectrum and the catalytic parameters of the recombinant enzyme in the γ- and β-elimination reactions of amino acids, and some sulfoxides of amino acids were obtained. For the first time, the possibility of usage of the enzyme for effective conversion of sulfoxides was established and the antimicrobial activity of thiosulfinates against Gram-negative and Gram-positive bacteria in situ was shown.

The multiresistance of A. ruhlandii 155B, B. cenocepacia 122, and P. aeruginosa 48B strains isolated from patients with cystic fibrosis was established. The antibacterial effect of allicin, dimethyl thiosulfinate, and dipropyl thiosulfinate on multidrug-resistant strains was shown. Thiosulfinates can have both bacteriostatic and bactericidal effects depending on the microorganism and the concentration. The studied thiosulfinates may be candidates for the development of alternative antibiotic drugs to treat infections caused by multidrug-resistant pathogens.

No abstract

No abstract