Purification and Properties of Proline-Rich Antimicrobial Peptides from Sheep and Goat Leukocytes (original) (raw)
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ChBac3.4: A Novel Proline-Rich Antimicrobial Peptide from Goat Leukocytes
Int J Pept Res Ther, 2009
We isolated a new proline-rich peptide, ChBac3.4, from leukocytes of the goat (Capra hirca) and determined its amino acid sequence by Edman degradation and mass spectrometry. ChBac3.4 (RFRLPFRRPPIRIHP PPFYPPFRRFL-NH2) had over 50% sequence identity to the Bac5 peptides found in the leukocytes of goats, sheep and cattle.
Infection and drug resistance, 2018
A peptide of 2,733 Da named SP-E, previously isolated from pig saliva and already described for its antifungal activity and absence of toxicity against mammalian cells, is characterized by a high content of proline residues (70% of entire sequence), that confer structural features probably related to peptide activity. The aim of this study was to evaluate the activity of SP-E against Gram-negative bacteria, including drug-resistant clinical isolates. SP-E and shorter fragments of the same peptide were tested in vitro against the selected bacteria by colony forming unit assays. Scanning electron microscopy and confocal microscopy were also applied. SP-E potential therapeutic activity was evaluated in vivo in a model of bacterial infection. SP-E proved to be active against the tested bacteria with EC values in the micro-molar range. Though maintaining antibacterial properties, the shorter peptides showed lower activity in respect to the parental molecule. Kinetics of killing action an...
ChemMedChem, 2019
Proline-rich antimicrobial peptides (PrAMPs) are promising agents to combat multi-drug resistant pathogens due to a high antimicrobial activity, yet low cytotoxicity. A library of derivatives of the PrAMP Bac5(1-17) was synthesized and screened to identify which residues are relevant for its activity. In this way, we discovered that two central motifs-PIRXP-cannot be modified, while residues at N-and C-termini tolerated some variations. We found five Bac5(1-17) derivatives bearing 1-5 substitutions, with an increased number of arginine and/or tryptophan residues, exhibiting improved antimicrobial activity and broader spectrum of activity while retaining low cytotoxicity toward eukaryotic cells. Transcription/translation and bacterial membrane permeabilization assays showed that these new derivatives still retained the ability to strongly inhibit bacterial protein synthesis, but also acquired permeabilizing activity to different degrees. These new Bac5(1-17) derivatives therefore show a dual mode of action which could hinder the selection of bacterial resistance against these molecules.
Proline-rich antimicrobial peptides: converging to a non-lytic mechanism of action
Cellular and Molecular Life Sciences, 2011
Proline-rich antimicrobial peptides are a group of cationic host defense peptides of vertebrates and invertebrates characterized by a high content of proline residues, often associated with arginine residues in repeated motifs. Those isolated from some mammalian and insect species, although not evolutionarily related, use a similar mechanism to selectively kill Gram-negative bacteria, with a low toxicity to animals. Unlike other types of antimicrobial peptides, their mode of action does not involve the lysis of bacterial membranes but entails penetration into susceptible cells, where they then act intracellularly. Some aspects of the transport system and cytoplasmic targets have been elucidated. These features make them attractive both as anti-infective lead compounds and as a new class of potential cell-penetrating peptides capable of internalising membrane-impermeant drugs into both bacterial and eukaryotic cells
ChemMedChem, 2019
Proline-rich antimicrobial peptides (PrAMPs) are promising agents to combat multi-drug resistant pathogens due to a high antimicrobial activity, yet low cytotoxicity. A library of derivatives of the PrAMP Bac5(1-17) was synthesized and screened to identify which residues are relevant for its activity. In this way, we discovered that two central motifs-PIRXP-cannot be modified, while residues at N-and C-termini tolerated some variations. We found five Bac5(1-17) derivatives bearing 1-5 substitutions, with an increased number of arginine and/or tryptophan residues, exhibiting improved antimicrobial activity and broader spectrum of activity while retaining low cytotoxicity toward eukaryotic cells. Transcription/translation and bacterial membrane permeabilization assays showed that these new derivatives still retained the ability to strongly inhibit bacterial protein synthesis, but also acquired permeabilizing activity to different degrees. These new Bac5(1-17) derivatives therefore show a dual mode of action which could hinder the selection of bacterial resistance against these molecules.
The Antibacterial Effect of a Proline-Rich Antibacterial Peptide A3-APO
Current Medicinal Chemistry, 2009
Antimicrobial resistance is an emerging worldwide concern in light of the widespread antimicrobial drug use in humans, livestock and companion animals. The treatment of life-threatening infections is especially problematic because clinical strains rapidly acquire multiple-drug resistance. Antimicrobial peptides have long been considered to be viable alternatives to small molecule antibiotics. However, the peptides' parenteral use is frequently hampered by inadequate safety margins and rapid renal clearance leaving them suitable only for topical applications. The proline-rich peptide A3-APO represents a family of a new class of synthetic dimers that kill bacteria by a dual mode of action and carry domains for interaction with both the bacterial membrane and an intracellular target. From a series of designer antibacterial peptides, A3-APO emerged as a viable preclinical candidate by virtue of its superior ability to disintegrate the bacterial membrane, inhibit the 70-kDa heat shock protein DnaK alone or in synergy with small molecule antibiotics, lack of eukaryotic toxicity and withstand proteolytic degradation in body fluids. As many other proline-rich peptides, A3-APO binds to the C-terminal helical lid of bacterial DnaK and inhibits chaperone-assisted protein folding in bacteria but not in mammalian Hsp70. In this review, the structure, pharmacokinetic properties, antimicrobial spectrum of peptide A3-APO and its in vivo metabolite are summarized and the in vitro and in vivo antimicrobial effects (antimicrobial susceptibilities, postantibiotic effects, resistance induction) are discussed in detail.
Alternative stabilities of a proline-rich antibacterial peptide in vitro and in vivo
Protein Science, 2008
The proline-rich designer antibacterial peptide dimer A3-APO is currently under preclinical development for the treatment of systemic infections caused by antibiotic-resistant Gram-negative bacteria. The peptide showed remarkable stability in 25% mouse serum in vitro, exhibiting a half-life of ;100 min as documented by reversed-phase chromatography. Indeed, after a 30-min incubation period in undiluted mouse serum ex vivo, mass spectrometry failed to identify any degradation product. The peptide was still a major peak in full blood ex vivo, however, with degradation products present corresponding to aminoterminal cleavage. When injected into mice intravenously, very little, if any unmodified peptide could be detected after 30 min. Nevertheless, the major early metabolite, a full single-chain fragment, was detectable until 90 min, and this fragment exhibited equal or slightly better activity in the broth microdilution antimicrobial assay against a panel of resistant Enterobactericeae strains. The Chex1-Arg20 metabolite, when administered three times at 20 mg/kg to mice infected with a sublethal dose (over LD 50 ) of an extended spectrum b-lactamase-producing Escherichia coli strain, completely sterilized the mouse blood, similar to imipenem added at a higher dose. The longer and presumably more immunogenic prodrug A3-APO, injected subcutaneously twice over a 3-wk period, did not induce any antibody production, indicating the suitability of this peptide or its active metabolite for clinical development.
Prophenin-1, an exceptionally proline-rich antimicrobial peptide from porcine leukocytes
FEBS Letters, 1995
We purified and characterized an unusual antimicrobial peptide, prophenin-1 (PF-I), from porcine leukocytes. The peptide had a mass of 8,683 and contained 79 residues, including 42 (53.2%) prolines and 15 (19.0%) phenylalanines. Its N-terminal 60 residues consisted of three perfect and three nearly perfect repeats of a decamer, FPPPNFPGPR. Prophenin-I was encoded on a cathelin-containing precursor and showed substantially more activity against E. coli, a Gram-negative bacterium, than against Listeria monocytogenes, a Gram-positive organism, in vitro. .
Isolation and characterisation of antimicrobial peptides from deer neutrophils
International Journal of Antimicrobial Agents, 2005
The New Zealand deer industry is the largest and most advanced in the world. Antimicrobial peptides have been isolated from a wide range of organisms, but as yet there have been no reports on any from deer. This work investigates the antimicrobial activity and characterisation of peptides isolated from Cervus elaphus blood. It was found that deer blood contains proline/arginine-rich cathelicidins, similar to Bac5 peptides isolated from cattle, sheep and goats. A -defensin was also isolated that had a conserved amino acid sequence and mass similar to bovine neutrophil -defensins. The cathelicidin displayed strong activity against Gram-negative bacteria, but lesser activity against Gram-positive bacteria and yeast, whilst the -defensin showed good activity against all three test organisms.