d-Amino acids in antimicrobial peptides: a potential approach to treat and combat antimicrobial resistance

Abstract

Antimicrobial resistance is one of the leading challenges in the human healthcare segment. Advances in antimicrobial resistance has trigger to explore naturally occurring alternatives to stabilize its seriousness. Antimicrobial peptides are small positively charged oligopeptides and are equally potent as that of commercially available antibiotics against broad class of organisms such as Gram-positive bacteria, Gram-negative bacteria, viruses and fungal strains. Along with this, they possess anticancerous activity, activates immune response and regulates inflammation. Peptides have discrete mode of action and fall into various categories due to their amino acid composition. Although Antimicrobial peptides specifically target bacterial cytoplasmic membrane but they can also target their nucleus and protein synthesis as well. Due to increasing demand of novel treatment therapy against brooding antimicrobial resistance, naturally synthesized peptides are a beneficial concept of development. Antimicrobial peptides are pervasive and can be easily modified using de-novo synthesis technology. Antimicrobial peptides can be isolated from natural resources such as humans, plants, bacteria and fungi. This review gives a brief over antimicrobial peptides and its diastereomeric composition. Further current trends and future scope associated with antimicrobial peptides and role of D-amino acids is also discussed with specific emphasis on the design and development of new drugs.

Vibrational circular dichroism of d‐amino acid‐containing peptide NdWFamide in the crystal form

“…The obtained mirror-image pattern revealed the high reliability of VCD peaks. Consequently, seven VCD signals (1)(2)(3)(4)(5)(6)(7) and (1 0 -7 0 ) of 1p and 1e were readily identified. The three couplet bands (1-3) of 1p appeared at 1680, 1671, and 1631 cm À1 with À, +, and À signs, respectively, whereas the corresponding mirror-image bands (1 0 -3 0 ) of 1e exhibited the opposite signs (i.e., +, À, and +).…”

“…1,2 Ribosomally synthesized proteins containing only L-amino acids are used to generate DAACPs, and bioactive peptides can be created by various, subsequent, enzymatic post-translational modifications. 3,4 One example of these post-translational modifications is peptide isomerization, which facilitates the enzymatic conversion of specific residues in the N-terminal region of peptides from L-amino acids to D-amino acids. 3,4 To date, more than 50 types of DAACPs have been reported, where those possessing D-amino acids at the second position from the N-terminal exhibit specific bioactivity.…”

“…3,4 To date, more than 50 types of DAACPs have been reported, where those possessing D-amino acids at the second position from the N-terminal exhibit specific bioactivity. 3,4 In fact, several neuropeptides, such as acatin, fulicin, fulyal, GdYFD, and allatotropin-related peptide (ATRP), are DAACPs that include D-amino acid residues at the second position. [5][6][7][8] Moreover, dermorphin (Tyr-D-Ala-Phe-Gly-Tyr-Pro-Ser-NH 2 ), which is isolated from the skin secretions of Phyllomedusa sauvagei, is the first DAACP derived from frogs.…”

“…d ‐Amino acid‐containing peptides (DAACPs) exhibiting biological activities have been found in various species 1,2 . Ribosomally synthesized proteins containing only l ‐amino acids are used to generate DAACPs, and bioactive peptides can be created by various, subsequent, enzymatic post‐translational modifications 3,4 . One example of these post‐translational modifications is peptide isomerization, which facilitates the enzymatic conversion of specific residues in the N‐terminal region of peptides from l ‐amino acids to d ‐amino acids 3,4 .…”

“…One example of these post‐translational modifications is peptide isomerization, which facilitates the enzymatic conversion of specific residues in the N‐terminal region of peptides from l ‐amino acids to d ‐amino acids 3,4 . To date, more than 50 types of DAACPs have been reported, where those possessing d ‐amino acids at the second position from the N‐terminal exhibit specific bioactivity 3,4 . In fact, several neuropeptides, such as acatin, fulicin, fulyal, GdYFD, and allatotropin‐related peptide (ATRP), are DAACPs that include d ‐amino acid residues at the second position 5–8 .…”