Study of Novel Peptides for Antimicrobial Protection in Solution and on Cotton Fabric

Abstract

Some new N- and C-modified biomolecular peptide analogues of both VV-hemorphin-5 and VV-hemorphin-7 with varied amino acids (Cys, Glu, His), 1-adamantanecarboxylic acid, and niacin (nicotinic acid) were synthesized by solid-phase peptide synthesis—Fmoc (9-fluorenylmethoxy-carbonyl) chemistry and were characterized in water solutions with different pH using spectroscopic and electrochemical techniques. Basic physicochemical properties related to the elucidation of the peptide structure at physiological pH have been also studied. The results showed that the interaction of peptide compounds with light and electricity preserves the structural and conformational integrity of the compounds in the solutions. Moreover, textile cotton fibers were modified with the new compounds and the binding of the peptides to the surface of the material was proved by FTIR and SEM analysis. Washing the material with an alkaline soap solution did not show a violation of the modified structure of the cotton. Antiviral activity against the human respiratory syncytial virus (HRSV-S2) and human adenovirus serotype 5 (HAdV-5), the antimicrobial activity against B. cereus and P. aeruginosa used as model bacterial strains and cytotoxic effect of the peptide derivatives and modified cotton textile material has been evaluated. Antimicrobial tests showed promising activity of the newly synthesized compounds against the used Gram-positive and Gram-negative bacteria. The compounds C-V, H-V, AC-V, and AH-V were found slightly more active than NH7C and NCH7. The activity has been retained after the deposition of the compounds on cotton fibers.

Metal–Peptide Complexes with Antimicrobial Potential for Cotton Fiber Protection

“…The following paragraph of this manuscript discusses the bioassays conducted on solutions of the investigated metallopeptides on certain pathogens. The peptide compounds used as complexing ligands are, as previously noted, various modifications of natural VV-hemorphin-5 and VV-hemorphin-7 [ 23 ]. Unlike AC-V, the H-V analog contains a heterocyclic basic amino acid His with a donor nitrogen atom from an imidazole moiety, favorable for complexation [ 23 ].…”

“…The peptide compounds used as complexing ligands are, as previously noted, various modifications of natural VV-hemorphin-5 and VV-hemorphin-7 [ 23 ]. Unlike AC-V, the H-V analog contains a heterocyclic basic amino acid His with a donor nitrogen atom from an imidazole moiety, favorable for complexation [ 23 ]. The rest of the peptide compounds differ among themselves by the variety of amino acid residues with free functional groups: -COOH, -SH, guanidine, and pyridyl and their different polarity, charge, hydrophobicity, etc., which they attach to the final peptide molecule.…”

“…The synthesis of the starting compounds used as ligands is described in detail in [ 23 ]. The solid-phase peptide synthesis by Fmoc chemistry was used to obtain the compounds.…”

“…Hemorphin components VV-hemorphin-5 and VV-hemorphin-7 serve as the structural pillars of the examined ligands [ 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. In our previous work, the hemorphin peptides were modified at the N and C terminals with different residues: Cys, Glu, His, 1-adamantanecarboxylic acid, and Niacin (Nicotinic acid) (see Figure 1 ) [ 23 ]. A similar modification leads to the optimization of the physicochemical properties of the hemorphin peptides and can increase their antimicrobial potency [ 23 ].…”

“…In our previous work, the hemorphin peptides were modified at the N and C terminals with different residues: Cys, Glu, His, 1-adamantanecarboxylic acid, and Niacin (Nicotinic acid) (see Figure 1 ) [ 23 ]. A similar modification leads to the optimization of the physicochemical properties of the hemorphin peptides and can increase their antimicrobial potency [ 23 ]. Copper ions are also known to have an affinity to coordinate with the nitrogen of the peptide bond to form cyan-violet complex compounds [ 24 , 25 ].…”