Peptide name : Lasioglossin LL-III

Source/Organism : The Eusocial Bee, Broad-faced Furrow Bee

Linear/Cyclic : Linear

Chirality : Not found

Peptide length: 15

C-terminal modification: Linear

N-terminal modification : Amidation and esterification

Non-natural peptide information: None

Assay type : Not specified

Assay time : Not found

Activity : LC50 : > 200 µM

Cell line : Not found

Cancer type : Not specified

Other activity : Anti-microbial activity

Amino acid composition bar chart :

Molecular mass : 1766.264 Dalton

Aliphatic index : 1.62

Instability index : -14.96

Hydrophobicity (GRAVY) : 0.3733

Isoelectric point : 10.602

Charge (pH 7) : 4.729

Aromaticity : 0.066

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

Hydrophobic/hydrophilic ratio : 1.5

hydrophobic moment : -1.424

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

Most occurring amino acid : K

Most occurring amino acid frequency : 5

Least occurring amino acid : N

Least occurring amino acid frequency : 1

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

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@H](CC(N)=O)NC(=O)[C@@H](N)C(C)C)C(=O)N[C@@H](CC(C)C)C(=O)NCC(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](CCCCN)C(=O)O)C(C)C)C(C)C)[C@@H](C)CC)[C@@H](C)CC

1 : Cerovský V, et al. Lasioglossins: three novel antimicrobial peptides from the venom of the eusocial bee Lasioglossum laticeps (Hymenoptera: Halictidae). Chembiochem. 2009; 10:2089-99. doi: 10.1002/cbic.200900133

Paper title : Lasioglossins: three novel antimicrobial peptides from the venom of the eusocial bee Lasioglossum laticeps (Hymenoptera: Halictidae).

Doi : https://doi.org/10.1002/cbic.200900133

Abstract : Three novel structurally related pentadecapeptides, named lasioglossins, were isolated from the venom of the eusocial bee Lasioglossum laticeps. Their primary sequences were established as H-Val-Asn-Trp-Lys-Lys-Val-Leu-Gly-Lys-Ile-Ile-Lys-Val-Ala-Lys-NH(2) (LL-I), H-Val-Asn-Trp-Lys-Lys-Ile-Leu-Gly-Lys-Ile-Ile-Lys-Val-Ala-Lys-NH(2) (LL-II) and H-Val-Asn-Trp-Lys-Lys-Ile-Leu-Gly-Lys-Ile-Ile-Lys-Val-Val-Lys-NH(2) (LL-III). These lasioglossins exhibited potent antimicrobial activity against both Gram-positive and Gram-negative bacteria, low haemolytic and mast cell degranulation activity, and a potency to kill various cancer cells in vitro. The lasioglossin CD spectra were measured in the presence of trifluoroethanol and sodium dodecyl sulfate solution and indicated a high degree of alpha-helical conformation. NMR spectroscopy, which was carried out in trifluoroethanol/water confirmed a curved alpha-helical conformation with a concave hydrophobic and convex hydrophilic side. To understand the role of this bend on biological activity, we studied lasioglossin analogues in which the Gly in the centre of the molecule was replaced by other amino acid residues (Ala, Lys, Pro). The importance of the N-terminal part of the molecule to the antimicrobial activity was revealed through truncation of five residues from both the N and C termini of the LL-III peptide. C-terminal deamidation of LL-III resulted in a drop in antimicrobial activity, but esterification of the C terminus had no effect. Molecular modelling of LL-III and the observed NOE contacts indicated the possible formation of a bifurcated H-bond between hydrogen from the Lys15 CONH peptide bond and one H of the C-terminal CONH(2) to the Ile11 oxygen atom. Such interactions cannot form with C-terminal esterification.