Rudenko Natalia, Nagel Alexey, Zamyatina Anna, Karatovskaya Anna, Salyamov Vadim, Andreeva-Kovalevskaya Zhanna, Siunov Alexander, Kolesnikov Alexander, Shepelyakovskaya Anna, Boziev Khanafiy, Melnik Bogdan, Brovko Fedor, Solonin Alexander
Pushchino Branch, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 6 Prospekt Nauki, 142290 Pushchino, Moscow Region, Russia.
FSBIS FRC Pushchino Scientific Centre of Biological Research, G.K. Skryabin Institute of Biochemistry and Physiology of Microorganisms, Russian Academy of Sciences, 5 Prospekt Nauki, 142290 Pushchino, Moscow Region, Russia.
Toxins (Basel). 2020 Dec 19;12(12):806. doi: 10.3390/toxins12120806.
is the fourth most common cause of foodborne illnesses that produces a variety of pore-forming proteins as the main pathogenic factors. hemolysin II (HlyII), belonging to pore-forming β-barrel toxins, has a C-terminal extension of 94 amino acid residues designated as HlyIICTD. An analysis of a panel of monoclonal antibodies to the recombinant HlyIICTD protein revealed the ability of the antibody HlyIIC-20 to inhibit HlyII hemolysis. A conformational epitope recognized by HlyIIC-20 was found. by the method of peptide phage display and found that it is localized in the N-terminal part of HlyIICTD. The HlyIIC-20 interacted with a monomeric form of HlyII, thus suppressing maturation of the HlyII toxin. Protection efficiencies of various strains against HlyII were different and depended on the epitope amino acid composition, as well as, insignificantly, on downstream amino acids. Substitution of L324P and P324L in the hemolysins ATCC14579 and B771, respectively, determined the role of leucine localized to the epitope in suppressing the hemolysis by the antibody. Pre-incubation of HlyIIC-20 with HlyII prevented the death of mice up to an equimolar ratio. A strategy of detecting and neutralizing the toxic activity of HlyII could provide a tool for monitoring and reducing pathogenicity.
是食源性疾病的第四大常见病因，产生多种成孔蛋白作为主要致病因素。溶血素II（HlyII）属于成孔β-桶状毒素，有一个94个氨基酸残基的C末端延伸，称为HlyIICTD。对一组针对重组HlyIICTD蛋白的单克隆抗体的分析显示，抗体HlyIIC-20具有抑制HlyII溶血的能力。通过肽噬菌体展示方法发现了HlyIIC-20识别的一个构象表位，并且发现它位于HlyIICTD的N末端部分。HlyIIC-20与HlyII的单体形式相互作用，从而抑制HlyII毒素的成熟。各种菌株对HlyII的保护效率不同，这取决于表位氨基酸组成，以及对下游氨基酸的影响不显著。分别在溶血素ATCC14579和B771中用L324P和P324L进行替换，确定了位于表位的亮氨酸在抑制抗体溶血方面的作用。HlyIIC-20与HlyII预孵育直至等摩尔比可防止小鼠死亡。检测和中和HlyII毒性活性的策略可为监测和降低致病性提供一种工具。
