The effect of elongation of a peptide substituent with ArgSer motif on the antimicrobial properties of hemin derivatives

The natural metalloporphrin hemin possesses a number of properties that determine its attractiveness as a basis for creating potential medicines. The development of research in this area is restrained by hemin's pronounced toxicity, mainly in relation to normal red blood cells, and also by its water insolubility. We previously synthesized amino acid and peptide hemin derivatives with sufficient water solubility and in some cases high antimicrobial (antibacterial and antifungal) potency [1, 2]. In order to establish the relationship between structure and function, this paper studies the peptide substituent in hemin derivatives (HD) elongated by multiplying the -ArgSer- motif and its effect on the biological and physicochemical properties of their aqueous solutions. A nonlinear nonmonotonic dependence of their physicochemical properties and biological potency on the HD concentration and the length of peptide substituent was revealed based on calculations of hydrophilic properties of substituents in HD and a study by electron and laser correlation spectroscopy of their properties in aqueous solutions.