RPEP-00063 · 1987Two closely related 23-amino-acid peptides called magainins were isolated from the skin of the African clawed frog (Xenopus laevis). These peptides kill numerous species of bacteria and fungi at low concentrations, lyse protozoa through osmotic disruption, and are water-soluble and nonhemolytic — meaning they destroy microbes without damaging red blood cells.
Both peptides derive from a common precursor protein, as confirmed by partial cDNA sequencing. They differ by only two amino acid substitutions and are potentially amphiphilic (having both water-loving and fat-loving regions), which likely explains how they interact with microbial membranes.
Zasloff, M · Laboratory Study
RPEP-00105 · 1989The cecropin A(1-13)-melittin(1-13) hybrid was 100-fold more active against S. aureus and 10-fold more antimalarial than parent peptides, with no toxicity to red blood cells.
Boman, H G; Wade, D; Boman, I A; Wåhlin, B; Merrifield, R B · In Vitro
RPEP-00121 · 1989Cytolytic peptides from diverse species converge on a common structural motif: a cationic site flanked by a hydrophobic surface. This motif is necessary and sufficient for membrane-disrupting activity.
Kini, R M; Evans, H J · Review
RPEP-00176 · 1990D-enantiomers of cecropin A, magainin 2, and melittin retained equivalent antibacterial and channel-forming activity, confirming a non-receptor-mediated membrane disruption mechanism.
Wade, D; Boman, A; Wåhlin, B; Drain, C M; Andreu, D; Boman, H G; Merrifield, R B · In Vitro
RPEP-00233 · 1992Salmonella genes required for antimicrobial peptide resistance were also required for macrophage survival and mouse virulence. Mutants were sensitive to both insect and mammalian peptides.
Groisman, E A; Parra-Lopez, C; Salcedo, M; Lipps, C J; Heffron, F · Animal Study
RPEP-00252 · 1992Lactoferricin inhibited Listeria monocytogenes (4 serotypes) at 0.3-9 micrograms/ml. Bactericidal concentrations were slightly higher. Effectiveness comparable to clinical antibiotics.
Wakabayashi, Hiroyuki; Bellamy, Wayne; Takase, Mitsunori; Tomita, Mamoru · In Vitro
RPEP-00294 · 1994Cecropins, magainin, and melittin disrupted mitochondrial coupling, protein import, and respiration, while PR-39 was nearly inert toward mitochondria.
Hugosson, M; Andreu, D; Boman, H G; Glaser, E · In Vitro
RPEP-00297 · 1994Lactoferricin B showed broad-spectrum bactericidal activity at low concentrations, with enhanced effectiveness at lower pH and against actively growing bacteria.
Jones, E M; Smart, A; Bloomberg, G; Burgess, L; Millar, M R · In Vitro
RPEP-00330 · 1995Brucella species showed broad resistance to 14 antimicrobial peptides, with their outer membranes remaining intact and binding less antimicrobial peptide than susceptible bacteria.
Martínez de Tejada, G; Pizarro-Cerdá, J; Moreno, E; Moriyón, I · In Vitro
RPEP-00360 · 1996Cecropin B was the most potent antimicrobial peptide against B. pertussis, with cecropins generally outperforming magainins, defensins, and protamine.
Fernandez, R C; Weiss, A A · In Vitro
RPEP-00363 · 1996Antimicrobial peptide effectiveness against Brucella abortus depended significantly on bacterial surface structure, with rough mutants showing different susceptibility patterns than smooth strains.
Halling, S M · In Vitro
RPEP-00376 · 1996Pardaxin possesses high antibacterial activity, and engineered variants achieved potent bacterial killing while reducing harmful effects on mammalian cells.
Oren, Z; Shai, Y · In Vitro
RPEP-00399 · 1997Antimicrobial peptide effectiveness against mollicutes varied dramatically by species, with animal defense peptides being less potent than venom and bacterial peptides. Multiple cellular effects preceded killing.
Béven, L; Wróblewski, H · In Vitro
RPEP-00405 · 1997Three cationic antibacterial peptides purified from lactoferrin's N-terminus showed activity against enterotoxigenic E. coli, with one being particularly potent.
Dionysius, D A; Milne, J M · In Vitro
RPEP-00411 · 1997Recombinant chymosin digestion of lactoferrin yielded multiple antimicrobial peptides including lactoferricin B and novel variants with antibacterial activity.
Hoek, K S; Milne, J M; Grieve, P A; Dionysius, D A; Smith, R · In Vitro
RPEP-00427 · 1997Hybrid peptides from cecropin A-magainin 2 and cecropin A-melittin showed antitumor activity, with structure-activity relationships enabling separation of cancer-killing from hemolytic effects.
Shin, S Y; Lee, M K; Kim, K L; Hahm, K S · In Vitro
RPEP-00441 · 1997Lactoferricin B at concentrations up to 50 μg/ml induced dose- and time-dependent apoptosis in THP-1 human monocytic leukemia cells, with reactive oxygen species playing a key mechanistic role.
Yoo, Y C; Watanabe, R; Koike, Y; Mitobe, M; Shimazaki, K; Watanabe, S; Azuma, I · In Vitro
RPEP-00451 · 1998Specific amino acid and peptide preparations enhanced immune responses, increased phagocytic activity, and protected splenocytes from benzene and aflatoxin B1 toxicity.
Belokrylov, G A; Derevnina, O Y; Molchanova, I V; Sorochinskaya, E I · Animal Study
RPEP-00468 · 1998The cecropin A-magainin 2 hybrid peptide disrupts membranes via a two-step mechanism, and leucine substitution analogs showed enhanced membrane disruption and antitumor activity with preserved low hemolytic toxicity.
Kang, J H; Shin, S Y; Jang, S Y; Lee, M K; Hahm, K S · In Vitro
RPEP-00472 · 1998Lactoferricin was detected and quantified in human serum for the first time using SELDI affinity mass spectrometry, establishing its natural occurrence in the bloodstream.
Kuwata, H; Yip, T T; Yip, C L; Tomita, M; Hutchens, T W · In Vitro
RPEP-00473 · 1998Affinity mass spectrometry enabled direct detection and quantification of lactoferricin and multiple lactoferrin-derived peptide fragments in human gastric contents, revealing the peptide generation process in detail.
Kuwata, H; Yip, T T; Yip, C L; Tomita, M; Hutchens, T W · In Vitro
RPEP-00474 · 1998Direct detection of lactoferricin generation in the human stomach after oral lactoferrin ingestion, providing the first in-vivo evidence of this bioactive peptide's natural formation during digestion.
Kuwata, H; Yip, T T; Tomita, M; Hutchens, T W · Clinical Trial
RPEP-00510 · 1999Solid-state NMR studies showed antimicrobial peptides adopt amphipathic helical structures oriented parallel to bacterial membrane surfaces, providing a structural basis for their selective membrane disruption mechanism.
Bechinger, B · Review
RPEP-00518 · 1999Sixteen novel cyclotides were identified from three plant species, all sharing the cyclic cystine knot motif that confers exceptional thermal, chemical, and enzymatic stability, with diverse bioactivities including antimicrobial and anti-HIV effects.
Craik, D J; Daly, N L; Bond, T; Waine, C · In Vitro
RPEP-00520 · 1999Antimicrobial peptide selectivity follows a balance: moderate hydrophobicity and amphipathicity maximize bacterial killing with minimal human cell toxicity, while excessive hydrophobicity increases toxicity without improving antibacterial activity.
Dathe, M; Wieprecht, T · Review
RPEP-00521 · 1999Periodontal pathogens P. gingivalis and Prevotella spp. produce extracellular proteases that degrade and inactivate antimicrobial peptides, representing a bacterial evasion mechanism against innate immune defenses in the oral cavity.
Devine, D A; Marsh, P D; Percival, R S; Rangarajan, M; Curtis, M A · In Vitro
RPEP-00548 · 1999Structural comparison revealed the cecropin-magainin hybrid has a bent helix with different hydrophobic surface distribution than the cecropin-melittin hybrid, explaining its superior bacterial selectivity and lower human cell toxicity.
Oh, D; Shin, S Y; Kang, J H; Hahm, K S; Kim, K L; Kim, Y · In Vitro
RPEP-00557 · 1999Structure-activity analysis identified the amphipathic helix hydrophobic face as essential for antibacterial activity, tryptophan as important for antitumor activity, and specific substitutions that separate antimicrobial potency from hemolytic toxicity.
Shin, S Y; Kang, J H; Hahm, K S · In Vitro
RPEP-00567 · 1999Macrocyclic cystine-knot peptides showed antimicrobial activity requiring both the intact circular backbone and disulfide knot; disrupting either eliminated structure and biological activity.
Tam, J P; Lu, Y A; Yang, J L; Chiu, K W · In Vitro
RPEP-00586 · 2000Alpha-MSH and its C-terminal tripeptide fragment KPV demonstrated direct antimicrobial activity against S. aureus, C. albicans, and E. coli, establishing a dual anti-inflammatory/antimicrobial function for this neuropeptide.
Catania, A; Cutuli, M; Garofalo, L; Carlin, A; Airaghi, L; Barcellini, W; Lipton, J M · In Vitro
RPEP-00588 · 2000Alpha-MSH and KPV demonstrated broad-spectrum antimicrobial activity including against MRSA and drug-resistant organisms, with an anti-Candida mechanism resembling amphotericin B membrane disruption.
Cutuli, M; Cristiani, S; Lipton, J M; Catania, A · In Vitro
RPEP-00636 · 2000Multiple host-defense peptides including lactoferricin and magainin-related peptides directly inactivated HSV-1 and HSV-2 in a validated microplate screening assay, expanding their known antimicrobial spectrum to include antiviral activity.
Yasin, B; Pang, M; Turner, J S; Cho, Y; Dinh, N N; Waring, A J; Lehrer, R I; Wagar, E A · In Vitro
RPEP-00713 · 2002Native bovine lactoferrin and derived peptides (lactoferricin) inhibited HIV entry into cells, with positively charged proteins/peptides showing the strongest activity, supporting milk-derived compounds as natural antivirals.
Berkhout, Ben; van Wamel, Jeroen L B; Beljaars, Leonie; Meijer, Dirk K F; Visser, Servaas; Floris, René · In Vitro
RPEP-00725 · 2002Bovine lactoferricin inhibited tumor growth in immunodeficient mice, proving a direct cytotoxic antitumor mechanism independent of immune system activation, likely through cancer cell membrane disruption.
Eliassen, Liv Tone; Berge, Gerd; Sveinbjørnsson, Baldur; Svendsen, John S; Vorland, Lars H; Rekdal, Øystein · Animal Study
RPEP-00763 · 2002Bovine lactoferricin induced apoptosis in human HL-60 leukemia cells more potently than intact lactoferrin, with activity dependent on native protein structure, demonstrating structure-specific anti-leukemic killing.
Roy, M K; Kuwabara, Y; Hara, K; Watanabe, Y; Tamai, Y · In Vitro
RPEP-00768 · 2002Macrocyclic hairpin mimetics of protegrin I demonstrated broad-spectrum antibacterial activity including against resistant strains, with improved stability over linear peptide antibiotics and activity maintained in challenging conditions.
Shankaramma, Sasalu C; Athanassiou, Zafiria; Zerbe, Oliver; Moehle, Kerstin; Mouton, Carole; Bernardini, Francesca; Vrijbloed, Jan W; Obrecht, Daniel; Robinson, John A · In Vitro
RPEP-00783 · 2002Lactoferricin B synergized with sub-inhibitory minocycline and monoacylglycerol for enhanced killing of S. aureus including MRSA, achieving bactericidal activity at concentrations ineffective individually.
Wakabayashi, Hiroyuki; Teraguchi, Susumu; Tamura, Yoshitaka · In Vitro
RPEP-00796 · 2003Macrocyclic peptides designed to bind Holliday DNA junctions showed antibacterial activity, validating a completely novel antibiotic mechanism targeting bacterial DNA repair/recombination.
Bolla, Megan L; Azevedo, Enrique V; Smith, Jason M; Taylor, Rachel E; Ranjit, Dev K; Segall, Anca M; McAlpine, Shelli R · In Vitro
RPEP-00805 · 2003Five synthetic 5-amino-acid peptides designed from lactoferricin's principles of lipophilic bulk and cationic charge showed potent broad-spectrum antibacterial activity, demonstrating ultra-short peptide antibiotics are viable.
Chen, Po-Wen; Shyu, Ching-Ling; Mao, Frank C · In Vitro
RPEP-00811 · 2003Lactoferrin's anti-adenovirus activity was mediated through its heparin-interacting domains, which compete with viral attachment to cell surface heparan sulfate — a mechanism explaining its broad antiviral spectrum against heparan sulfate-binding viruses.
Di Biase, Assunta Maria; Pietrantoni, Agostina; Tinari, Antonella; Siciliano, Rosa; Valenti, Piera; Antonini, Giovanni; Seganti, Lucilla; Superti, Fabiana · In Vitro
RPEP-00814 · 2003Bulky aromatic amino acid substitutions and lipophilic modifications enhanced bovine lactoferricin antitumor activity in a 15-residue fragment, with tryptophan residues identified as essential for cancer cell killing through membrane-disrupting mechanisms.
Eliassen, Liv Tone; Haug, Bengt Erik; Berge, Gerd; Rekdal, Oystein · In Vitro
RPEP-00830 · 2003A structure-based macrocyclic peptide deformylase inhibitor showed potent enzyme inhibition with a novel antibiotic mechanism targeting an essential bacterial enzyme absent in humans.
Hu, Xubo; Nguyen, Kiet T; Verlinde, Christophe L M J; Hol, Wim G J; Pei, Dehua · In Vitro
RPEP-00847 · 2003High hydrostatic pressure sensitized Salmonella typhimurium and Pseudomonas aeruginosa outer-membrane mutants to lactoferrin, lactoferricin, and other antimicrobial peptides through outer membrane disruption.
Masschalck, Barbara; Deckers, Daphne; Michiels, Chris W · In Vitro
RPEP-00869 · 2003Lactoferricin demonstrates antibacterial, antifungal, antiviral, antiparasitic, antitumor, and immunomodulatory activities — establishing it as a remarkably multi-functional peptide derived from the common milk protein lactoferrin.
Wakabayashi, H; Takase, M; Tomita, M · Review
RPEP-00879 · 2004Cecropin A, melittin, magainin, and indolicidin demonstrated antiviral activity against both Junin virus (arenavirus) and HSV-1, expanding the antimicrobial peptide antiviral spectrum to include hemorrhagic fever viruses.
Albiol Matanic, Vanesa C; Castilla, Viviana · In Vitro
RPEP-00902 · 2004Bovine lactoferricin dose-dependently reduced Yersinia adhesion to and invasion of HEp-2 cells even at sub-bactericidal concentrations, demonstrating anti-virulence activity complementing its bactericidal effects.
Di Biase, Assunta Maria; Tinari, Antonella; Pietrantoni, Agostina; Antonini, Giovanni; Valenti, Piera; Conte, Maria Pia; Superti, Fabiana · In Vitro
RPEP-00912 · 2004Lactoferricin-derived peptides bound bacterial LPS and showed antimicrobial activity against E. coli including LPS mutant strains, with activity correlating with LPS binding — confirming membrane interaction as the killing mechanism.
Farnaud, Sebastien; Spiller, Claire; Moriarty, Laura C; Patel, Alpesh; Gant, Vanya; Odell, Edward W; Evans, Robert W · In Vitro
RPEP-00913 · 2004Bovine lactoferricin's superior antimicrobial activity versus human lactoferricin was explained by more complete amphipathic beta-sheet formation and denser cationic surface charge distribution, identified through 3D structural modeling.
Farnaud, Sebastien; Patel, Alpesh; Odell, Edward W; Evans, Robert W · In Vitro
RPEP-00938 · 2004Novel pentadecapeptides designed by computational prediction from lactoferricin's activity features demonstrated real antibacterial activity against test organisms, validating in-silico antimicrobial peptide design approaches.
Lejon, Tore; Stiberg, Trine; Strøm, Morten B; Svendsen, John S · In Vitro
RPEP-00943 · 2004Lactoferricin inhibited Listeria monocytogenes adhesion to and internalization by THP-1 human macrophages, reducing early infection events beyond direct bacterial killing — demonstrating anti-virulence protection.
Longhi, Catia; Conte, Maria P; Penta, Michela; Cossu, Alessia; Antonini, Giovanni; Superti, Fabiana; Seganti, Lucilla · In Vitro