Peptide name : Ss-arasin

Source/Organism : The Indian mud crab

Linear/Cyclic : Linear

Chirality : Not found

Peptide length: 22

C-terminal modification: Linear

N-terminal modification : Free

Non-natural peptide information: None

Assay type : MTT assay

Assay time : 24h

Activity : IC 50 : 2.90 μM

Cell line : HT-29

Cancer type : Colon carcinoma

Other activity : Anti-microbial activity

Amino acid composition bar chart :

Molecular mass : 2432.037 Dalton

Aliphatic index : 1.95

Instability index : 1.8273

Hydrophobicity (GRAVY) : 1.9727

Isoelectric point : 4.5296

Charge (pH 7) : -1.5039

Aromaticity : 0.045

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

Hydrophobic/hydrophilic ratio : 3.4

hydrophobic moment : 0.4217

Missing amino acid : W,H,Q,P,K,S,D,Y,N,G

Most occurring amino acid : L

Most occurring amino acid frequency : 7

Least occurring amino acid : M

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.5, 0, 0.6)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](N)CCSC)[C@@H](C)O)C(=O)N[C@H](C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@H](C(=O)N[C@@H](CS)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](CC(C)C)C(=O)N[C@@H](C)C(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@@H](C)C(=O)N[C@@H](CCC(=O)O)C(=O)N[C@@H](C)C(=O)O)[C@@H](C)O)C(C)C)C(C)C)C(C)C

1 : Anju A, et al. Molecular characterization, recombinant expression and bioactivity profile of an antimicrobial peptide, Ss-arasin from the Indian mud crab, Scylla serrata. Fish Shellfish Immunol. 2019; 88:352-358. doi: 10.1016/j.fsi.2019.03.007

Paper title : Molecular characterization, recombinant expression and bioactivity profile of an antimicrobial peptide, Ss-arasin from the Indian mud crab, Scylla serrata.

Doi : https://doi.org/10.1016/j.fsi.2019.03.007

Abstract : Antimicrobial peptides (AMP) are potential alternatives to conventional antibiotics with the prospect to treat infections caused by multidrug resistant bacteria. This is the report of the first arasin sequence from the mud crab, Scylla serrata, designated as Ss-arasin. The complete cDNA sequences of the open reading frame (ORF) is comprised of 198 bp encoding 65 amino acid with a predicted molecular weight of 7 kDa and a predicted isoelectric point of 10.68. The sequence of the N-terminal 24 amino acid residues is indicative of a signal sequence directing the newly synthesize protein toward the secretory pathway. The 41-residue mature peptide is composed of two domains, an N-terminal Gly/Arg-rich domain and a C-terminal cysteine-rich domain. Challenging the mud crab with lipopolysaccharide (LPS) increased expression of Ss-arasin mRNA in haemocytes, reaching the highest level at 6 h, before dropping to basal levels at 24 h. Recombinant rSs-arasin showed antimicrobial activity against three bacterial species Staphylococcus aureus (40 mM), Pseudomonas aeruginosa (40 mM) and Escherichia coli (40 mM) implying significant anti-bacterial action. In addition, recombinant rSs-arasin inhibited human cervical carcinoma (HeLa) and colon carcinoma (HT-29) cell growth. These initial findings are encouraging to further study the structure-activity relationships to optimize these biological functions for future drug development.