Peptide name : Crotalicidin

Source/Organism : South American rattlesnake

Linear/Cyclic : Not found

Chirality : Not found

Peptide length: 194

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 : Not found

Amino acid composition bar chart :

Molecular mass : 22005.7409 Dalton

Aliphatic index : 0.717

Instability index : 56.1387

Hydrophobicity (GRAVY) : -0.554

Isoelectric point : 4.853

Charge (pH 7) : -11.3897

Aromaticity : 0.097

Molar extinction coefficient (cysteine, cystine): (23950, 24200)

Hydrophobic/hydrophilic ratio : 0.95959596

hydrophobic moment : 0.3821

Missing amino acid : None

Most occurring amino acid : E

Most occurring amino acid frequency : 33

Least occurring amino acid : H

Least occurring amino acid frequency : 1

Secondary structure fraction (Helix, Turn, Sheet): (0.4, 0.2, 0.3)

SMILES Notation: CC[C@H](C)[C@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@@H](NC(=O)[C@H](CO)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCCCN)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CCCCN)NC(=O)[C@@H](NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CCCCN)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(=O)O)NC(=O)CNC(=O)[C@H](CCCCN)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CC(N)=O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](C)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](C)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](NC(=O)CNC(=O)CNC(=O)[C@@H](NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](CS)NC(=O)[C@H](CO)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)[C@@H]1CCCN1C(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](CCC(=O)O)NC(=O)CNC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)CNC(=O)[C@@H](NC(=O)[C@H](CS)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@@H](NC(=O)CNC(=O)[C@H](CC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](Cc1ccccc1)NC(=O)CNC(=O)[C@H](CS)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H](NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CS)NC(=O)[C@H](C)NC(=O)[C@@H](NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CCCCN)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](CC(N)=O)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CCC(N)=O)NC(=O)[C@H](CO)NC(=O)CNC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CO)NC(=O)[C@H](CO)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CC(=O)O)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CCC(N)=O)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)[C@H](C)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@H](C)NC(=O)[C@H](CCC(=O)O)NC(=O)CNC(=O)[C@H](C)NC(=O)[C@H](CCCCN)NC(=O)CNC(=O)[C@H](CC(N)=O)NC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)[C@@H](NC(=O)[C@H](CO)NC(=O)[C@@H](NC(=O)[C@H](C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CCC(=O)O)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](C)NC(=O)[C@H](CCC(=O)O)NC(=O)CNC(=O)[C@H](Cc1ccc(O)cc1)NC(=O)[C@H](CO)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H]1CCCN1C(=O)[C@H](CCCNC(=N)N)NC(=O)[C@H](Cc1c[nH]cn1)NC(=O)[C@H](C)NC(=O)[C@H](CC(C)C)NC(=O)[C@H](CO)NC(=O)[C@H](C)NC(=O)[C@@H]1CCCN1C(=O)[C@@H](NC(=O)CNC(=O)[C@H](CS)NC(=O)[C@@H](NC(=O)[C@H](C)NC(=O)[C@H](CC(C)C)NC(=O)[C@@H](NC(=O)[C@H](CC(C)C)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@@H](NC(=O)[C@H](CCCCN)NC(=O)[C@H](Cc1c[nH]c2ccccc12)NC(=O)[C@H](Cc1ccccc1)NC(=O)[C@H](Cc1ccccc1)NC(=O)CNC(=O)[C@H](CCC(N)=O)NC(=O)[C@@H](N)CCSC)[C@@H](C)O)C(C)C)C(C)C)[C@@H](C)O)C(C)C)C(C)C)C(C)C)[C@@H](C)O)[C@@H](C)O)C(C)C)C(C)C)C(C)C)[C@@H](C)O)[C@@H](C)O)C(C)C)C(C)C)C(C)C)C(C)C)C(C)C)C(C)C)C(C)C)C(C)C)C(C)C)C(C)C)C(=O)N[C@@H](Cc1ccccc1)C(=O)N[C@@H](CCCCN)C(=O)N[C@@H](CCCCN)C(=O)N1CCC[C@H]1C(=O)N[C@@H](CCSC)C(=O)N[C@H](C(=O)N[C@H](C(=O)NCC(=O)N[C@H](C(=O)N[C@H](C(=O)N[C@H](C(=O)N1CCC[C@H]1C(=O)N[C@@H](Cc1ccccc1)C(=O)O)[C@@H](C)CC)[C@@H](C)O)C(C)C)[C@@H](C)CC)C(C)C

1 : Cavalcante CS, et al. Anti-fungal activity of Ctn[15-34], the C-terminal peptide fragment of crotalicidin, a rattlesnake venom gland cathelicidin. J Antibiot (Tokyo). 2017; 70:231-237. doi: 10.1038/ja.2016.135

2 : Bandeira ICJ, et al. Antichagasic effect of crotalicidin, a cathelicidin-like vipericidin, found in Crotalus durissus terrificus rattlesnake's venom gland. Parasitology. 2018; 145:1059-1064. doi: 10.1017/S0031182017001846

3 : Falcao CB, et al. Vipericidins: a novel family of cathelicidin-related peptides from the venom gland of South American pit vipers. Amino Acids. 2014; 46:2561-71. doi: 10.1007/s00726-014-1801-4

4 : Falcao CB, et al. Structural Dissection of Crotalicidin, a Rattlesnake Venom Cathelicidin, Retrieves a Fragment with Antimicrobial and Antitumor Activity. J Med Chem. 2015; 58:8553-63. doi: 10.1021/acs.jmedchem.5b01142

Paper title : Anti-fungal activity of Ctn[15-34], the C-terminal peptide fragment of crotalicidin, a rattlesnake venom gland cathelicidin.

Doi : https://doi.org/10.1038/ja.2016.135

Abstract : Crotalicidin (Ctn), a 34-residue cathelicidin from a South American rattlesnake, and its fragment (Ctn[15-34]) have shown anti-infective and cytotoxic activities against Gram-negative bacteria and certain tumor lines, respectively. The extent of such effects has been related to physicochemical characteristics such as helicity and hydrophobicity. We now report the anti-fungal activity of Ctn and its fragments (Ctn[1-14]) and (Ctn[15-34]). MIC determination and luminescent cell viability assays were used to evaluate the anti-infective activity of Ctn and its fragments (Ctn[1-14]) and (Ctn[15-34]) as anti-fungal agents against opportunistic yeast and dermatophytes. Cytotoxicity towards healthy eukaryotic cells was assessed in vitro with healthy human kidney-2 (HK-2) cells and erythrocytes. The checkerboard technique was performed to estimate the effects of combining either one of the peptides with amphotericin B. Ctn was the most active peptide against dermatophytes and also the most toxic to healthy eukaryotic cells. Fragments Ctn[1-14] and Ctn[15-35] lost activity against dermatophytes, but became more active against pathogenic yeasts, including several Candida species, both clinical isolates and standard strains, with MICs as low as 5 μm. Interestingly, the two peptide fragments were less cytotoxic to healthy HK-2 cells and less hemolytic to human erythrocytes than the standard-of-care amphotericin B. Also noteworthy was the synergy between Ctn peptides and amphotericin B, with consequent reduction in MICs of both drug and peptides. Altogether, Ctn and its fragments, particularly Ctn[15-34], are promising leads, either alone or in combined regimen with amphotericin B, for the treatment of fungal diseases.

Paper title : Antichagasic effect of crotalicidin, a cathelicidin-like vipericidin, found in Crotalus durissus terrificus rattlesnake's venom gland.

Doi : https://doi.org/10.1017/S0031182017001846

Abstract : Cathelicidins are antimicrobial peptides produced by humans and animals in response to various pathogenic microbes. Crotalicidin (Ctn), a cathelicidin-related vipericidin from the South American Crotalus durissus terrificus rattlesnake's venom gland, and its fragments have demonstrated antimicrobial and antifungal activity, similarly to human cathelicidin LL-37. In order to provide templates for the development of modern trypanocidal agents, the present study evaluated the antichagasic effect of these four peptides (Ctn, Ctn[1-14], Ctn[15-34] and LL-37). Herein, Ctn and short derived peptides were tested against the epimastigote, trypomastigote and amastigote forms of Trypanosoma cruzi Y strain (benznidazole-resistant strain) and cytotoxicity in mammalian cells was evaluated against LLC-MK2 lineage cells. Ctn inhibited all T. cruzi developmental forms, including amastigotes, which is implicated in the burden of infection in the chronic phase of Chagas disease. Moreover, Ctn showed a high selective index against trypomastigote forms (>200). Ctn induced cell death in T. cruzi through necrosis, as determined by flow cytometry analyses with specific molecular probes and morphological alterations, such as loss of membrane integrity and cell shrinkage, as observed through scanning electron microscopy. Overall, Ctn seems to be a promising template for the development of antichagasic agents.

Paper title : Vipericidins: a novel family of cathelicidin-related peptides from the venom gland of South American pit vipers.

Doi : https://doi.org/10.1007/s00726-014-1801-4

Abstract : Cathelicidins are phylogenetically ancient, pleiotropic host defense peptides-also called antimicrobial peptides (AMPs)-expressed in numerous life forms for innate immunity. Since even the jawless hagfish expresses cathelicidins, these genetically encoded host defense peptides are at least 400 million years old. More recently, cathelicidins with varying antipathogenic activities and cytotoxicities were discovered in the venoms of poisonous snakes; for these creatures, cathelicidins may also serve as weapons against prey and predators, as well as for innate immunity. We report herein the expression of orthologous cathelicidin genes in the venoms of four different South American pit vipers (Bothrops atrox, Bothrops lutzi, Crotalus durissus terrificus, and Lachesis muta rhombeata)-distant relatives of Asian cobras and kraits, previously shown to express cathelicidins-and an elapid, Pseudonaja textilis. We identified six novel, genetically encoded peptides: four from pit vipers, collectively named vipericidins, and two from the elapid. These new venom-derived cathelicidins exhibited potent killing activity against a number of bacterial strains (S. pyogenes, A. baumannii, E. faecalis, S. aureus, E. coli, K. pneumoniae, and P. aeruginosa), mostly with relatively less potent hemolysis, indicating their possible usefulness as lead structures for the development of new anti-infective agents. It is worth noting that these South American snake venom peptides are comparable in cytotoxicity (e.g., hemolysis) to human cathelicidin LL-37, and much lower than other membrane-active peptides such as mastoparan 7 and melittin from bee venom. Overall, the excellent bactericidal profile of vipericidins suggests they are a promising template for the development of broad-spectrum peptide antibiotics.

Paper title : Structural Dissection of Crotalicidin, a Rattlesnake Venom Cathelicidin, Retrieves a Fragment with Antimicrobial and Antitumor Activity.

Doi : https://doi.org/10.1021/acs.jmedchem.5b01142

Abstract : In silico dissection of crotalicidin (Ctn), a cathelicidin from a South American pit viper, yielded fragments Ctn[1-14] and Ctn[15-34], which were tested to ascertain to what extent they reproduced the structure and activity of the parent peptide. NMR data showing Ctn to be α-helical at the N-terminus and unstructured at the C-terminus were matched by similar data from the fragments. The peptides were tested against Gram-positive and -negative bacteria and for toxicity against both tumor and healthy cells. Despite its amphipathic α-helical structure, Ctn[1-14] was totally inert toward bacteria or eukaryotic cells. In contrast, unstructured Ctn[15-34] replicated the activity of parent Ctn against Gram-negative bacteria and tumor cells while being significantly less toxic toward eukaryotic cells. This selectivity for bacteria and tumor cells, plus a stability to serum well above that of Ctn, portrays Ctn[15-34] as an appealing candidate for further development as an anti-infective or antitumor lead.