Antimicrobial Peptides are GO! Defensins & Cathelicidins


Antimicrobial peptides (AMPs) are peptides that form part of the host's important innate immunity mechanism against pathogenic microorganisms such as Gram positive and negative bacteria, fungi and viruses.1-2 AMPs are short peptides (<60 amino acids), exhibit a broad-spectrum antimicrobial activity at physiological conditions and are predominantly cationic.2 Cathelicidins and defensins, the two extensively studied AMP families, are expressed in immune cells and at epithelial surfaces in humans.3-5

hCAP18, human cationic antimicrobial protein, with a MW of 18 kD, is the only cathelicidin gene found in humans.1 The N-terminus of this protein consists of a cathelin-like region (highly conserved among species) and a C-terminal termed LL-37.6-7 An amphipathic alpha-helical peptide, LL-37 plays an important role in the first line of defense against local infection and systemic invasion of pathogens at sites of inflammation and wounds. Cytotoxic to both bacterial and normal eukaryotic cells, LL-37 is significantly resistant to proteolytic degradation in solution.8-9 In addition to having antimicrobial activity, LL-37 has been shown to play a role in chemoattraction, dendritic cell differentiation, mast cell degranulation, cytokine secretion, angiogenesis stimulation, and wound healing.10 In other species, the C-terminal antimicrobial region varies in sizes, sequences and structures.10

The defensins are a large family of small, cationic, cysteine- and arginine-rich antimicrobial peptides. They are divided into five groups according to the spacing pattern of cysteines: plant, invertebrate, α-, β-, and θ-defensins. The latter three are mostly found in mammals. α-defensins are proteins found in neutrophils and intestinal epithelia. Human neutrophil peptides (HNP) 1-3 are microbicidal and cytotoxic defensins derived from a 94-amino acid prepro HNP1-94, co-translationally proteolyzed to proHNP20-94, then converted by removal of the anionic propiece to mature HNP65-94 (HNP-1 and -3) and HNP66-94 (HNP-2). HNP 1-4 comprise up to approximately 5% of the total cellular protein of neutrophils.11-13

New LL-37 Peptides

Table 1. Three recently released (July, 2013) LL-37 peptide fragments are listed below.

Product Size Catalog #

LL13-37 NEW

IGKEFKRIVQRIKDFLRNLVPRTES

1 mg

5 mg

65453-1

65453-5

LL-17-29 NEW

FKRIVQRIKDFLR

1 mg

5 mg

65454-1

65454-5

LL-17-32 NEW

FKRIVQRIKDFLRNLV

1 mg

5 mg

65452-1

65452-5

 

Table 2. A listing of LL-37 and other antimicrobial peptides.

Product Size Catalog #

LL - 37, Antimicrobial Peptide, human

LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES

1 mg

61302

LL-37, acetylated & amidated

Ac-LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES-NH2

1 mg

63710

LL-37 fragment (8-37), LL-8-37

KSKEKIGKEFKRIVQRIKDFLRNLVPRTES

1 mg

63711

LL-37 fragment (18-37), LL-18-37

KRIVQRIKDFLRNLVPRTES

1 mg

63712

5 - FAM - LC - LL - 37

5-FAM-LC-LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES

0.1 mg

63694

Biotin - LC - LL - 37

Biotin-LC-LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES

0.5 mg

63693

Cys - LC - LL - 37

C-LC-LLGDFFRKSKEKIGKEFKRIVQRIKDFLRNLVPRTES

1 mg

63692

LL - 37, reverse sequence

SETRPVLNRLFDKIRQVIRKFEKGIKEKSKRFFDGLL

0.5 mg

62208

LL-37, scrambled

GLKLRFEFSKIKGEFLKTPEVRFRDIKLKDNRISVQR

1 mg

63708

LL - 37 pentamide

LLGNFFRKSKQKIGKQFKRIVQRIKNFFRNLVPRTQS; more potent than LL-37

1 mg

61309

Dermcidin, DCD-1L

SSLLEKGLDGAKKAVGGLGKLGKDAVEDLESVGKGAVHDVKDVLDSVL

0.5 mg

63713

mCRAMP, mouse
GLLRKGGEKIGEKLKKIGQKIKNFFQKLVPQPEQ
; mouse cathelicidin-related antimicrobial peptide

1 mg

61305

rCRAMP
GLVRKGGEKFGEKLRKIGQKIKEFFQKLALEIEQ
; rat cathelicidin-related antimicrobial peptide

1 mg

61306

 



Table 3. A listing of defensin peptides.

Product Size Catalog #

hBD - 1, β - Defensin - 1, human
DHYNCVSSGGQCLYSACPIFTKIQGTCYRGKAKCCK (Disulfide bridge: 5 - 34, 12 - 27, 17 - 35)

0.1 mg

60740

hBD - 3, β - Defensin - 3, human
GIINTLQKYYCRVRGGRCAVLSCLPKEEQIGKCSTRGRKCCRRKK
(Disulfide bridge: 11 - 40, 18 - 33, 23 - 41)

0.1 mg

60741

hBD - 4, β - Defensin - 4, human
ELDRICGYGTARCRKKCRSQEYRIGRCPNTYACCLRK (Disulfide bridge: 6 - 33; 13 - 27; 17 - 34)

0.1 mg

60742

HNP - 1, Defensin Human Neutrophil Peptide - 1
ACYCRIPACIAGERRYGTCIYQGRLWAFCC (Disulfide bridge: 2 - 30, 4 - 19, 9 - 29)

0.1 mg

60743

HNP - 2, Defensin Human Neutrophil Peptide - 2
CYCRIPACIAGERRYGTCIYQGRLWAFCC (Disulfide bridge: 1 - 29, 3 - 18, 8 - 28)

0.1 mg

60744

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