Peptide name : Nigrocin-M1

Source/Organism : Synthetic

Linear/Cyclic : Linear

Chirality : L

Peptide length: 21

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information:

Assay type : MTT assay

Assay time : 24-h

Activity : IC50 = 24.60 μM

Cell line : MCF-7

Cancer type : Breast Cancer

Other activity : Antimicrobial and Antitumor

Amino acid composition bar chart :

Molecular mass : 2006.518 Dalton

Aliphatic index : 1.809

Instability index : -1.519

Hydrophobicity (GRAVY) : 1.2571

Isoelectric point : 10.302

Charge (pH 7) : 2.7571

Aromaticity : 0

Molar extinction coefficient (cysteine, cystine): (0, 0)

Hydrophobic/hydrophilic ratio : 4.25

hydrophobic moment : -1.329

Missing amino acid : C,D,E,F,H,M,N,P,Q,R,T,W,Y

Most occurring amino acid : L

Most occurring amino acid frequency : 7

Least occurring amino acid : I

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (52., 33., 47.)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CCCCN)NC(=O)CNC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC(C)C)NC(=O)CN)C(=O)N[C@@H](CC(C)C)C(=O)NCC(=O)N[C@@H](C)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)NCC(=O)N[C@H](C(=O)N[C@@H](CO)C(=O)NCC(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)O)C(C)C)C(C)C

1 : Lu C, et al. A novel antimicrobial peptide found in Pelophylax nigromaculatus. J Genet Eng Biotechnol. 2022; 20:76. doi: 10.1186/s43141-022-00366-9

Paper title : A novel antimicrobial peptide found in Pelophylax nigromaculatus.

Doi : https://doi.org/10.1186/s43141-022-00366-9

Abstract : BACKGROUND: Many active peptides have been found in frog skin secretions. In this paper, our research focused on Pelophylax nigromaculatus and found a broad-spectrum antimicrobial peptide Nigrocin-PN based on the molecular cloning technique. Thereafter, the "Rana box" function was briefly studied by two mutated peptides (Nigrocin-M1 and Nigrocin-M2). Furthermore, in vitro and in vivo assays were used to characterize the peptide's biofunctions, and the peptide's function in treating multidrug-resistant pathogens was also studied. RESULTS: Nigrocin-PN not only displayed potent antimicrobial abilities in vitro but also significantly ameliorated pulmonary inflammation induced by Klebsiella pneumoniae in vivo. By comparing, leucine-substituted analogue Nigrocin-M1 only displayed bactericidal abilities towards gram-positive bacteria, while the shorter analogue Nigrocin-M2 lost this function. More strikingly, Nigrocin-PN exhibited synergistic effects with commonly used antibiotics; in vitro evolution experiments revealed that coadministration between Nigrocin-PN and ampicillin could delay Staphylococcus aureus antibiotic resistance acquisition. Kinetics and morphology studies indicate that antibacterial mechanisms involved membrane destruction. Furthermore, toxicities and anticancer abilities of these peptides were also studied; compared to two analogues, Nigrocin-PN showed mild haemolytic activity and indistinctive cytotoxicity towards normal cell lines HMEC-1 and HaCaT. CONCLUSIONS: A broad-spectrum antimicrobial peptide Nigrocin-PN was discovered from the skin secretion of Pelophylax nigromaculatus. Structurally, "Rana box" played a crucial role in reducing toxicities without compromising antibacterial abilities, and Nigrocin-PN could be a desired therapeutic candidate.