Table 1 Landmark papers in identification and establishment of the CS-αβ superfamily

1985

Charybdotoxin from Leiurus quinquestriatus (deathstalker, Palestine/Israeli yellow scorpion), inhibits Ca²⁺-activated K⁺ channels

6

G+, G−, Y

[13, 17, 18]

1985

Defensins from human neutrophils, similar to peptides isolated from rabbit neutrophils

6

G+, G−, Y, V

[1]

1988

Sapecins from Sarcophaga peregrina (flesh fly), similarity to mammalian defensins noted, but the name “defensin” was not applied to these peptides

6

G+, G−

[5, 72, 99]

1989

Phormicins/Phormia defensins from Protophormia terraenovae (northern blow fly, blue-bottle fly), proposal of term “insect defensin”

6

G+, G−, F (Y)

[4, 46, 47]

1991

Establishment of CSH motif in arthropod neurotoxic peptides

4

[12]

1992

RsAFP1/RsAFP2–antifungal peptides from Raphanus sativus (radish), noted that based on structure, RsAFPs belonged to a superfamily of small, basic, cysteine-rich proteins with antibacterial activity (including plant thionins, and mammalian and insect defensins), but that RsAFPs were unique due to their specific activity against filamentous fungi; “plant defensin” term proposed in 1995

8

RsAFP1: F (G+, G−, Y, C, H) RsAFP2: F, G+ (G−, Y, C, H)

[8, 9, 61]

1993

Scorpion defensin from Leiurus quinquestriatus (deathstalker, Palestine/Israeli yellow scorpion), similarity to both insect defensins and scorpion toxins noted as well as the ability of the scorpion to produce both a toxin and a defensin

6

G+ (G−)

[28]

1994

Defensin from Drosophila melanogaster (fruit fly)

6

G+

[50]

1994

Drosomycin from Drosophila melanogaster (fruit fly), noted similarity to plant antifungal peptides

8

F, Y, P (G+, G−, H)

[10, 100]

1995

Establishment of CS-αβ fold by adding third disulphide bond to the CSH motif (study used Phormia defensin A)

[11]

1996

MGD-1–defensin 1 from Mytilus galloprovincialis (Mediterranean mussel), considered to be part of arthropod defensin group with two additional cysteines

8

G+, G−, F (C), some fragments active against Y and P

[34, 54, 55, 101, 102]

1996

Defensins and mytilins from Mytilus edulis (blue mussel), some sequences incomplete, mytilins proposed as a different group based on position of cysteines in primary structure

6–8

G+, G−

[57]

1996

ASABF–antibacterial factor from Ascaris suum (large roundworm of pigs), noted similarity to plant defensins and drosomycin

8

G+, G− (F)

[59]

1999

Myticins from Mytilus galloprovincialis (Mediterranean mussel), myticins proposed as a different group based on position of cysteines in primary structure

8

G+, G−, F (P)

[56]

2002

Ce-ABF2–antibacterial factor 2 from Caenorhabditis elegans

8

G+, G−, Y

[60]

2004

Theromacin from Theromyzon tessulatum (duck leech), cysteine array originally thought to not be similar to arrays of other C-rich peptides

10

G+ (G−, F)

[39]

2005

Plectasin–fungal defensin from Pseudoplectania nigrella (ebony cup)

6

G+ (G−)

[33]

2007

AdDLP–defensin-like peptide from Anaeromyxobacter dehalogenans (bacteria) hypothesized ancestor of group, has only the CSH motif

4

P (G+, G−, F, Y, H)

[19, 20]

2009

Hydramacin from Hydra magnipapillata, noted similarity to scorpion toxin superfamily

8

G+, G−

[40, 41]

2011

ASABF-related peptide from Suberites domuncula (sponge)

8

G+, G−, F, Y, H

[36]

2012

Neuromacin and theromacin from Hirudo medicinalis (medicinal leech)

8–10

G+, G−

[40]

2012

Micasin–defensin-like peptide from Arthroderma otae/Microsporum canis

6

G+, G− (F, Y, H)

[24]

2013

Mytimacin -AF from Achatina fulica (giant African snail)

10

G+, G−, Y (H)

[44]

2014

Cremycins–drosomycin-like antifungal peptides from Caenorhabditis remanei, cysteine number and spacing not consistent with drosomycin, not all have antifungal activity

6

Cremycin 5: F, Y (G+, G−, H) Cremycin-15: G+, G− (F, Y)

[21]