Computational Prediction and Structural Analysis of α-Hairpinins, a Ubiquitous Family of Antimicrobial Peptides, Using the Cysmotif Searcher Pipeline.

Background: α-Hairpinins are a family of antimicrobial peptides, promising antimicrobial agents, which includes only 12 currently revealed members with proven activity, although their real number is supposed to be much higher. α-Hairpinins are short peptides containing four cysteine residues arranged in a specific Cys-motif. These antimicrobial peptides (AMPs) have a characteristic helix-loop-helix structure with two disulfide bonds.

Complex of Defense Polypeptides of Wheatgrass () Associated with Plant Immunity to Biotic and Abiotic Stress Factors.

Plant defense polypeptides play a crucial role in providing plants with constitutive immunity against various biotic and abiotic stressors. In this study, we explored a complex of proteins from wheatgrass () spikelets to estimate their role in the plant's tolerance to various environmental factors. The current research shows that in vitro protein extracts from spikelets possess antifungal activity against certain species, which are specific cereal pathogens, at concentrations of 1-2 mg/mL.

New l-Rhamnose-Binding Lectin from the Bivalve : Purification, Partial Structural Characterization and Antibacterial Activity.

In this study, a new l-rhamnose-binding lectin (GYL-R) from the hemolymph of bivalve was purified using affinity and ion-exchange chromatography and functionally characterized. Lectin antimicrobial activity was examined in different ways. The lectin was inhibited by saccharides possessing the same configuration of hydroxyl groups at C-2 and C-4, such as l-rhamnose, d-galactose, lactose, l-arabinose and raffinose.

Recombinant Fusion Protein Containing Plant Nigellothionin Regulates the Growth of Food-Spoiling Fungus ().

This study aimed to obtain a recombinant chimeric protein named trx-NsW2 via theheterologous expression of the multifunctional antimicrobial peptide nigellothionin from black cumin ( L.) seeds in the system. The protein was purified using a combination of Ni-NTA affinity chromatography and reversed-phase HPLC.

Diversity of Cationic Antimicrobial Peptides in Black Cumin ( L.) Seeds.

Black cumin ( L.) is known to possess a wide variety of antimicrobial peptides belonging to different structural families. Three novel antimicrobial peptides have been isolated from black cumin seeds.

Molecular Cloning and Characteristics of a Lectin from the Bivalve .

C-type lectins (CTLs) are a family of carbohydrate-binding proteins that mediate multiple biological events, including adhesion between cells, the turnover of serum glycoproteins, and innate immune system reactions to prospective invaders. Here, we describe the cDNA cloning of lectin from the bivalve (GYL), which encodes 161 amino acids and the C-type carbohydrate recognition domain (CRD) with EPN and WND motifs. The deduced amino acid sequence showed similarity to other CTLs.

First Anti-Inflammatory Peptide AnmTX Sco 9a-1 from the Swimming Sea Anemone .

A novel peptide AnmTX Sco 9a-1 with the β-hairpin fold was isolated from the swimming sea anemone (Actinostolidae family). The peptide consists of 28 amino acid residues, including modified hydroxyproline residue, and its measured molecular mass is 2960 Da. The peptide was not toxic on mice; however, it stimulated their exploratory motivation and active search behavior, and demonstrated an anti-anxiety effect.

C Fullerene Clusters Stabilize the Biologically Inactive Form of Topotecan.

There is a range of experimental proofs that biologically relevant compounds change their activity in the presence of C fullerene clusters in aqueous solution, which most frequently act as a nanoplatform for drug delivery. Inspired by this evidence, we made an effort to investigate the interaction of fullerene clusters with the antibiotic topotecan (TPT). This study proceeded in three steps, namely, UV/vis titration to confirm complexation and in vitro assays on proliferating and nonproliferating cells to elucidate the role of C fullerene in the putative change in TPT activity.

Oak bark (Quercus sp. cortex) protects plants through the inhibition of quorum sensing mediated virulence of Pectobacterium carotovorum.

Bacterial intercellular communication mediated by small diffusible molecules, known as quorum sensing (QS), is a common mechanism for regulating bacterial colonisation strategies and survival. Influence on QS by plant-derived molecules is proposed as a strategy for combating phytopathogens by modulating their virulence. This work builds upon other studies that have revealed plant-derived QS inhibitors extracted from oak bark (Quercus sp.

Isolation and Characterization of a Novel Hydrophobin, Sa-HFB1, with Antifungal Activity from an Alkaliphilic Fungus, .

The adaptations that alkaliphilic microorganisms have developed due to their extreme habitats promote the production of active natural compounds with the potential to control microorganisms, causing infections associated with healthcare. The primary purpose of this study was to isolate and identify a hydrophobin, Sa-HFB1, from an alkaliphilic fungus, . A potential antifungal effect against pathogenic and opportunistic fungi strains was determined.

Rational Design of Plant Hairpin-like Peptide EcAMP1: Structural-Functional Correlations to Reveal Antibacterial and Antifungal Activity.

Plant antimicrobial peptides from the α-hairpinins family (hairpin-like peptides) are known to possess a wide range of biological activities. However, less is known about the structural determinants of their antimicrobial activity. Here, we suggest that spatial structure as well as surface charge and hydrophobicity level contribute to the antimicrobial properties of α-hairpinin EcAMP1 from barnyard grass () seeds.

Exploring Peptaibol's Profile, Antifungal, and Antitumor Activity of Emericellipsin A of Species from Soda and Saline Soils.

Features of the biochemical adaptations of alkaliphilic fungi to exist in extreme environments could promote the production of active antibiotic compounds with the potential to control microorganisms, causing infections associated with health care. Thirty-eight alkaliphilic and alkalitolerant Emericellopsis strains (E. alkalina, E.

High Resistance of Potato to Early Blight Is Achieved by Expression of the Gene for Hevein-Like Antimicrobial Peptides from Common Chickweed ().

In the common chickweed , two antimicrobial peptides (AMPs), SmAMP1.1a and SmAMP1.2a, have been shown to be proteolytically released as products of the expression of a single gene, .

Gausemycins A,B: Cyclic Lipoglycopeptides from Streptomyces sp.*.

We report a novel family of natural lipoglycopeptides produced by Streptomyces sp. INA-Ac-5812. Two major components of the mixture, named gausemycins A and B, were isolated, and their structures were elucidated.

The Emericellipsins A-E from an Alkalophilic Fungus Show Potent Activity against Multidrug-Resistant Pathogenic Fungi.

Novel antimicrobial peptides with antifungal and cytotoxic activity were derived from the alkalophilic fungus VKPM F1428. We previously reported that this strain produced emericellipsin A (EmiA), which has strong antifungal and cytotoxic properties. Further analyses of the metabolites obtained under a special alkaline medium resulted in the isolation of four new homologous (Emi B-E).

Nigellothionins from Black Cumin ( L.) Seeds Demonstrate Strong Antifungal and Cytotoxic Activity.

High-cationic biologically active peptides of the thionins family were isolated from black cumin ( L.) seeds. According to their physicochemical characteristics, they were classified as representatives of the class I thionin subfamily.

Seasonal changes in kinetic parameters of trypsin in gastric and agastric fish.

The objective of the present study was to assess if trypsin, a key enzyme involved in protein digestion, presents some kind of functional adaptations to seasonal changes in water temperature in freshwater fish. In order to test this hypothesis, individuals of two fish species Carassius gibelio (agastric) and Perca fluviatilis (gastric) were sampled in the basin of Chany Lake (Siberia, Russia) at two different seasons (spring and summer). Apparent kinetic parameters (K and V) were determined for both species and seasons at the actual pH values in fish guts, and at actual temperatures.

Isolation of antimicrobial peptides from different plant sources: Does a general extraction method exist?

Plants are good sources of biologically active compounds with antimicrobial activity, including polypeptides. Antimicrobial peptides (AMPs) represent one of the main barriers of plant innate immunity to environmental stress factors and are attracting much research interest. There are some extraction methods for isolation of AMPs from plant organs based on the type of extractant and initial fractionation stages.

Peptide Extracts from Seven Medicinal Plants Discovered to Inhibit Oomycete a Causative Agent of Potato Late Blight Disease.

We report the inhibitory effect of peptide extracts obtained from seven medicinal plants against a causative agent of late blight disease We find that all the extracts possess inhibitory activity toward the zoospores output, zoosporangium germination, and the development of on potato disc tubers at different quantitative levels. Based on the biological effects detected, an extract of common horsetail () biomass is recognized as the most effective and is selected for further structural analysis. We perform a combination of amino acid analysis and MALDI-TOF mass spectrometry, which reveal the presence of Asn/Asp- and Gln/Glu-rich short peptides with molecular masses in the range of 500-900 Da and not exceeding 1500 Da as the maximum.

Antimicrobial Activity of Microorganisms Isolated from Ant Nests of .

In this study, the microbial communities of two nests of black garden ants ) in the hollows of stem branches of old apple trees were found to have similar species compositions: each community contained representatives of three species from the Bacillaceae family and one species of actinomycetes from the genus . In total, four types of bacilli and two actinomycetes were isolated. Actinomycetes were identified as -like and sp.

Defense Peptides From the α-Hairpinin Family Are Components of Plant Innate Immunity.

Plant immunity represents a sophisticated system, including both basal and inducible mechanisms, to prevent pathogen infection. Antimicrobial peptides (AMPs) are among the innate immunity components playing a key role in effective and rapid response against various pathogens. This review is devoted to a small family of defense peptides called α-hairpinins.

Isolation and partial structural characterization of new Kunitz-type trypsin inhibitors from the pike cestode Triaenophorus nodulosus.

The inhibitors produced by the parasitic worms successfully protect them from the host's proteases and are supposed to underlie the host-parasite specificity. Our previous study has shown that the extracts from the pike tapeworm Triaenophorus nodulosus inhibit host proteinases and commercial trypsin. We aimed to isolate and identify the components responsible for trypsin inactivation.

Sub-inhibitory Effects of Antimicrobial Peptides.

Antimicrobials, and particularly antimicrobial peptides (AMPs), have been thoroughly studied due to their therapeutic potential. The research on their exact mode of action on bacterial cells, especially at under sublethal concentrations, has resulted in a better understanding of the unpredictable nature of bacterial behavior under stress conditions. In this review, we were aiming to gather the wide yet still under-investigated knowledge about various AMPs and their subinhibition effects on cellular and molecular levels.