Peptide name : Halictine 2

Source/Organism : Venom, the eusocial bee

Linear/Cyclic : Not found

Chirality : L

Peptide length: 12

C-terminal modification: Not found

N-terminal modification : Free

Non-natural peptide information: None

Assay type : Not specified

Assay time : Not found

Activity : Not found

Cell line : Not found

Cancer type : Not found

Other activity : Anti-microbial activity; Hemolytic activity

Amino acid composition bar chart :

Molecular mass : 1453.8364 Dalton

Aliphatic index : 1.3

Instability index : 96.9583

Hydrophobicity (GRAVY) : 0.0667

Isoelectric point : 10.302

Charge (pH 7) : 2.8443

Aromaticity : 0.083

Molar extinction coefficient (cysteine, cystine): (5500, 5500)

Hydrophobic/hydrophilic ratio : 1.4

hydrophobic moment : -1.256

Missing amino acid : C,R,Q,T,P,E,F,D,Y,N,A,V

Most occurring amino acid : K

Most occurring amino acid frequency : 3

Least occurring amino acid : G

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.5, 0.1, 0.4)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@H](CCSC)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@H](CCCCN)NC(=O)CN)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CCCCN)C(=O)O

1 : Monincová L, et al. Novel antimicrobial peptides from the venom of the eusocial bee Halictus sexcinctus (Hymenoptera: Halictidae) and their analogs. Amino Acids. 2010; 39:763-75. doi: 10.1007/s00726-010-0519-1

Paper title : Novel antimicrobial peptides from the venom of the eusocial bee Halictus sexcinctus (Hymenoptera: Halictidae) and their analogs.

Doi : https://doi.org/10.1007/s00726-010-0519-1

Abstract : Two novel antimicrobial peptides, named halictines, were isolated from the venom of the eusocial bee Halictus sexcinctus. Their primary sequences were established by ESI-QTOF mass spectrometry, Edman degradation and enzymatic digestion as Gly-Met-Trp-Ser-Lys-Ile-Leu-Gly-His-Leu-Ile-Arg-NH2 (HAL-1), and Gly-Lys-Trp-Met-Ser-Leu-Leu-Lys-His-Ile-Leu-Lys-NH2 (HAL-2). Both peptides exhibited potent antimicrobial activity against Gram-positive and Gram-negative bacteria but also noticeable hemolytic activity. The CD spectra of HAL-1 and HAL-2 measured in the presence of trifluoroethanol or SDS showed ability to form an amphipathic alpha-helical secondary structure in an anisotropic environment such as bacterial cell membrane. NMR spectra of HAL-1 and HAL-2 measured in trifluoroethanol/water confirmed formation of helical conformation in both peptides with a slightly higher helical propensity in HAL-1. Altogether, we prepared 51 of HAL-1 and HAL-2 analogs to study the effect of such structural parameters as cationicity, hydrophobicity, alpha-helicity, amphipathicity, and truncation on antimicrobial and hemolytic activities. The potentially most promising analogs in both series are those with increased net positive charge, in which the suitable amino acid residues were replaced by Lys. This improvement basically relates to the increase of antimicrobial activity against pathogenic Pseudomonas aeruginosa and to the mitigation of hemolytic activity.