0000000000117125
AUTHOR
Jose F. Marcos
Tryptophan-Containing Dual Neuroprotective Peptides: Prolyl Endopeptidase Inhibition and Caenorhabditis elegans Protection from β-Amyloid Peptide Toxicity
Neuroprotective peptides represent an attractive pharmacological strategy for the prevention or treatment of age-related diseases, for which there are currently few effective therapies. Lactoferrin (LF)-derived peptides (PKHs) and a set of six rationally-designed tryptophan (W)-containing heptapeptides (PACEIs) were characterized as prolyl endopeptidase (PEP) inhibitors, and their effect on β-amyloid peptide (Aβ) toxicity in a Caenorhabditis elegans model of Alzheimer’s disease (AD) was evaluated. Two LF-derived sequences, PKH8 and PKH11, sharing a W at the C-terminal end, and the six PACEI heptapeptides (PACEI48L to PACEI53L) exhibited significant in vitro PEP inhibition. The inhibitory pe…
Stabilisation of mixed peptide/lipid complexes in selective antifungal hexapeptides
AbstractThe design of antimicrobial peptides could have benefited from structural studies of known peptides having specific activity against targetmicrobes, but not toward other microorganisms. We have previously reported the identification of a series of peptides (PAF-series) activeagainst certain postharvest fungal phytopathogens, and devoid of toxicity towards E. coli and S. cerevisiae [Lo´pez-Garci´a et al. Appl.Environ. Microbiol. 68 (2002) 2453]. The peptides inhibited the conidia germination and hyphal growth. Here, we present a comparativestructural characterisation of selected PAF peptides obtained by single-amino-acid replacement, which differ in biological activity. Thepeptides w…
Comparison of the activity of antifungal hexapeptides and the fungicides thiabendazole and imazalil against postharvest fungal pathogens
8 pages, 2 figures, 3 tables.-- PMID: 14623382 [PubMed].-- Printed version published Dec 31, 2003.
Novel antihypertensive hexa- and heptapeptides with ACE-inhibiting properties: From the in vitro ACE assay to the spontaneously hypertensive rat
Bioactive ACE inhibiting peptides are gaining interest in hypertension treatment. We have designed and screened six synthetic heptapeptides (PACEI48 to PACEI53) based on two hexapeptide leads (PACEI32 and PACEI34) to improve ACE inhibitory properties and assess their antihypertensive effects. ACE activity was assayed in vitro and ex vivo. Selected peptides were administered to spontaneously hypertensive rats (SHRs) and normotensive Wistar-Kyoto (WKY) rats. In vitro cytotoxicity was assessed with the MTT reduction test. The six heptapeptides at low micromolar concentration produced different degrees of in vitro inhibition of ACE activity using the synthetic substrate HHL or the natural subst…
Bovine lactoferrin pepsin hydrolysate exerts inhibitory effect on angiotensin I-converting enzyme-dependent vasoconstriction
Abstract The inhibitory effect of a pepsin hydrolysate of bovine lactoferrin (LFH) on angiotensin I-converting enzyme (ACE) has been examined using in vitro and ex vivo functional assays. In vitro assays showed a LFH inhibitory effect on ACE activity with an IC 50 value of 0.95±0.06 mg mL −1 . Ex vivo functional assays using rabbit carotid artery segments showed a LFH inhibitory effect on ACE-dependent angiotensin I-induced contraction, but not on angiotensin II-induced contraction, suggesting that the effect of LFH is not due to antagonism of receptors for angiotensin II. LFH was shown to possess ACE inhibitory effect with potential to modulate hypertension, although the possible inhibitor…
Transient structural ordering of the RNA-binding domain of carnation mottle virus p7 movement protein modulates nucleic acid binding.
Plant viral movement proteins bind to RNA and participate in the intra- and intercellular movement of the RNAs from plant viruses. However, the role and magnitude of the conformational changes associated with the formation of RNA-protein complexes are not yet defined. Here we describe studies on the relevance of a preexisting nascent alpha-helix at the C terminus of the RNA-binding domain of p7, a movement protein from carnation mottle virus, to RNA binding. Synthetic peptide analogues and single amino acid mutation at the RNA-binding domain of recombinant p7 protein were used to correlate the transient structural order in aqueous solution with RNA-binding potential.
Antihypertensive properties of lactoferricin B-derived peptides.
A set of eight lactoferricin B (LfcinB)-derived peptides was examined for inhibitory effects on angiotensin I-converting enzyme (ACE) activity and ACE-dependent vasoconstriction, and their hypotensive effect in spontaneously hypertensive rats (SHR). Peptides were derived from different elongations both at the C-terminal and N-terminal ends of the representative peptide LfcinB(20-25), which is known as the LfcinB antimicrobial core. All of the eight LfcinB-derived peptides showed in vitro inhibitory effects on ACE activity with different IC(50) values. Moreover, seven of them showed ex vivo inhibitory effects on ACE-dependent vasoconstriction. No clear correlation between in vitro and ex viv…
Antihypertensive effect of a bovine lactoferrin pepsin hydrolysate: Identification of novel active peptides
et al.
Potential of Antifungal Proteins (AFPs) to Control Penicillium Postharvest Fruit Decay
Penicillium phytopathogenic species provoke severe postharvest disease and economic losses. Penicillium expansum is the main pome fruit phytopathogen while Penicillium digitatum and Penicillium italicum cause citrus green and blue mold, respectively. Control strategies rely on the use of synthetic fungicides, but the appearance of resistant strains and safety concerns have led to the search for new antifungals. Here, the potential application of different antifungal proteins (AFPs) including the three Penicillium chrysogenum proteins (PAF, PAFB and PAFC), as well as the Neosartorya fischeri NFAP2 protein to control Penicillium decay, has been evaluated. PAFB was the most potent AFP against …
Structural Properties of Carnation Mottle Virus p7 Movement Protein and Its RNA-binding Domain
Plant viral movement proteins (MPs) participate actively in the intra- and intercellular movement of RNA plant viruses to such an extent that MP dysfunction impairs viral infection. However, the molecular mechanism(s) of their interaction with cognate nucleic acids are not well understood, partly due to the lack of structural information. In this work, a protein dissection approach was used to gain information on the structural and RNA-binding properties of this class of proteins, as exemplified by the 61-amino acid residue p7 MP from carnation mottle virus (CarMV). Circular dichroism spectroscopy showed that CarMV p7 is an alpha/beta RNA-binding soluble protein. Using synthetic peptides de…
Identification of Novel Hexapeptides Bioactive against Phytopathogenic Fungi through Screening of a Synthetic Peptide Combinatorial Library
The purpose of the present study was to improve the antifungal activity against selected phytopathogenic fungi of the previously identified hexapeptide PAF19. We describe some properties of a set of novel synthetic hexapeptides whose D-amino acid sequences were obtained through screening of a synthetic peptide combinatorial library in a positional scanning format. As a result of the screening, 12 putative bioactive peptides were identified, synthesized, and assayed. The peptides PAF26 (Ac-rkkwfw-NH(2)), PAF32 (Ac-rkwhfw-NH(2)), and PAF34 (Ac-rkwlfw-NH(2)) showed stronger activity than PAF19 against isolates of Penicillium digitatum, Penicillium italicum, and Botrytis cinerea. PAF26 and PAF3…
Vasoactive properties of antihypertensive lactoferrin-derived peptides in resistance vessels: Effects in small mesenteric arteries from SHR rats
Aims: Bovine lactoferrin (LF) hydrolysates and peptides identified thereof have shown antihypertensive effects in rat models, mainly but not exclusively by angiotensin-converting enzyme inhibition. In this study we aimed to assess the vasoactive effects and mechanisms of an ultrafiltered (< 3 kDa) pepsin LF hydrolysate (LFH) and a heptapeptide identified in a LF hydrolysate produced by yeast proteolysis (DPYKLRP) in peripheral resistance arteries from spontaneously hypertensive rats (SHRs). Main methods: We used a myograph system for isometric tension recording in isolated small mesenteric arteries from SHRs. Direct vasoactive effects of LFH (30–100 μg/mL) and DPYKLRP (30–100 μM) were asses…
In vivo detection, RNA-binding properties and characterization of the RNA-binding domain of the p7 putative movement protein from carnation mottle carmovirus (CarMV).
Biochemical and structural characterization studies on the p7 putative movement protein from a Spanish isolate of carnation mottle carmovirus (CarMV) have been conducted. The CarMV p7 gene was fused to a sequence coding for a six-histidine tag and expressed in bacteria, allowing the purification of CarMV p7 and the production of a specific antiserum. This antiserum led to the immunological identification of CarMV p7 in infected leaf tissue from the experimental host Chenopodium quinoa. Putative nucleic acid-binding properties of the CarMV p7 have been explored and demonstrated with both electrophoretic mobility shift and RNA-protein blot in vitro assays using digoxigenin-labeled riboprobes.…
Differential susceptibility of mycotoxin-producing fungi to distinct antifungal proteins (AFPs).
Abstract The global challenge to prevent fungal spoilage and mycotoxin contamination on foods and feeds require the development of new antifungal strategies. Filamentous fungi encode diverse antifungal proteins (AFPs), which offer a great potential for the control of contaminant fungi. In this study, four AFPs from Penicillium digitatum (PdAfpB) and Penicillium expansum (PeAfpA, PeAfpB and PeAfpC) belonging to classes A, B and C, were tested against a representative panel of mycotoxin-producing fungi. They included a total of 38 strains representing 32 different species belonging to the genera Alternaria, Aspergillus, Byssochlamys, Fusarium and Penicillium. PeAfpA exhibited a potent antifun…
Insertion and Topology of a Plant Viral Movement Protein in the Endoplasmic Reticulum Membrane
Virus-encoded movement proteins (MPs) mediate cell-to-cell spread of viral RNA through plant membranous intercellular connections, the plasmodesmata. The molecular pathway by which MPs interact with viral genomes and target plasmodesmata channels is largely unknown. The 9-kDa MP from carnation mottle carmovirus (CarMV) contains two potential transmembrane domains. To explore the possibility that this protein is in fact an intrinsic membrane protein, we have investigated its insertion into the endoplasmic reticulum membrane. By using in vitro translation in the presence of dog pancreas microsomes, we demonstrate that CarMV p9 inserts into the endoplasmic reticulum without the aid of any addi…
Development of a FungalBraid Penicillium expansum-based expression system for the production of antifungal proteins in fungal biofactories
Fungal antifungal proteins (AFPs) have attracted attention as novel biofungicides. Their exploitation requires safe and cost-effective producing biofactories. Previously, Penicillium chrysogenum and Penicillium digitatum produced recombinant AFPs with the use of a P. chrysogenum-based expression system that consisted of the paf gene promoter, signal peptide (SP)-pro sequence and terminator. Here, the regulatory elements of the afpA gene encoding the highly produced PeAfpA from Penicillium expansum were developed as an expression system for AFP production through the FungalBraid platform. The afpA cassette was tested to produce PeAfpA and P. digitatum PdAfpB in P. chrysogenum and P. digitatu…