HBD-2 interactions with erythrocyte membranes in vitro

• Main Authors: M. V. Makarenko, D. O. Semeniuk, I. O. Starenka, A. P. Pogribna, I. V. Sokol, L. I. Martinova, D. O. Govsieiev
• Format: Article
• Language: English
• Published: National Academy of Sciences of Ukraine and Palladin Institute of Biochemistry of the National Academy of Sciences of Ukraine. 2019-02-01
• Series: Ukrainian Biochemical Journal
• Subjects: hemolytic activity; human beta-defensin 2; membrane permeabilization
• Online Access: http://ukrbiochemjournal.org/wp-content/uploads/2019/01/Makarenko_1_19.pdf
• ISSN: 2409-4943; 2413-5003

HBD-2 – a member of β-defensin family of antimicrobial peptides – is known to permeabilize cell membranes of susceptible cells, but the mechanism of such interactions is poorly understood. In our study, we have used a hemolytic model to explore the kinetic properties of HBD-2 interactions with membranes of human erythrocytes. We ran hemolytic assays with a wide range of both HBD-2 and erythrocyte concentrations, as well as varying pH values, incubation times, and osmotic strengths; each in the presence or the absence of inhibitory substances such as proteins and salts. The results show that HBD-2 cell membrane permeabilization is both dose- and time-dependent (with plateau effect observed in each case), and inversely dependent on erythrocyte concentration. HBD-2 interactions with cell membranes highly depend on pH value and the presen­ce of inhibitors but are not affected by tested osmotic strength range. Our findings suggest that interactions of HBD-2 with cell membranes are mainly electrostatic in nature and are limited by released cell content. We have developed a speculative model of such interaction based on our results.