scholarly journals Worms’ Antimicrobial Peptides

Marine Drugs ◽  
2019 ◽  
Vol 17 (9) ◽  
pp. 512 ◽  
Author(s):  
Bruno ◽  
Maresca ◽  
Canaan ◽  
Cavalier ◽  
Mabrouk ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Structural Characteristics ◽  
Parallel Evolution ◽  
Microbial Pathogens ◽  
Core Motif ◽  
Life Styles ◽  
Unique System ◽  
The Face ◽  
Living Organisms ◽  
Net Positive Charge

Antimicrobial peptides (AMPs) are natural antibiotics produced by all living organisms. In metazoans, they act as host defense factors by eliminating microbial pathogens. But they also help to select the colonizing bacterial symbionts while coping with specific environmental challenges. Although many AMPs share common structural characteristics, for example having an overall size between 10–100 amino acids, a net positive charge, a γ-core motif, or a high content of cysteines, they greatly differ in coding sequences as a consequence of multiple parallel evolution in the face of pathogens. The majority of AMPs is specific of certain taxa or even typifying species. This is especially the case of annelids (ringed worms). Even in regions with extreme environmental conditions (polar, hydrothermal, abyssal, polluted, etc.), worms have colonized all habitats on Earth and dominated in biomass most of them while co-occurring with a large number and variety of bacteria. This review surveys the different structures and functions of AMPs that have been so far encountered in annelids and nematodes. It highlights the wide diversity of AMP primary structures and their originality that presumably mimics the highly diverse life styles and ecology of worms. From the unique system that represents marine annelids, we have studied the effect of abiotic pressures on the selection of AMPs and demonstrated the promising sources of antibiotics that they could constitute.

scholarly journals Attacins: A Promising Class of Insect Antimicrobial Peptides

Antibiotics ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 212
Author(s):  
Francesco Buonocore ◽  
Anna Maria Fausto ◽  
Giulia Della Pelle ◽  
Tomislav Roncevic ◽  
Marco Gerdol ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Effect ◽  
Short Review ◽  
Microbial Pathogens ◽  
Special Focus ◽  
Gram Negative Bacteria ◽  
Physiological Importance ◽  
Related Proteins ◽  
Large Repertoire

Insects produce a large repertoire of antimicrobial peptides (AMPs) as the first line of defense against bacteria, viruses, fungi or parasites. These peptides are produced from a large precursor that contains a signal domain, which is cleaved in vivo to produce the mature protein with antimicrobial activity. At present, AMPs from insects include several families which can be classified as cecropins, ponericins, defensins, lebocins, drosocin, Metchnikowin, gloverins, diptericins and attacins according to their structure and/or function. This short review is focused on attacins, a class of glycine-rich peptides/proteins that have been first discovered in the cecropia moth (Hyalophora cecropia). They are a rather heterogeneous group of immunity-related proteins that exhibit an antimicrobial effect mainly against Gram-negative bacteria. Here, we discuss different attacin and attacin-like AMPs that have been discovered so far and analyze their structure and phylogeny. Special focus is given to the physiological importance and mechanism of action of attacins against microbial pathogens together with their potential pharmacological applications, emphasizing their roles as antimicrobials.

scholarly journals Proteomic response of Escherichia coli to a membrane lytic and iron chelating truncated Amaranthus tricolor defensin

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Tessa B. Moyer ◽  
Ashleigh L. Purvis ◽  
Andrew J. Wommack ◽  
Leslie M. Hicks
Keyword(s):  
Escherichia Coli ◽  
Antibacterial Activity ◽  
Antimicrobial Peptides ◽  
Mechanism Of Action ◽  
Gram Negative Bacteria ◽  
Amaranthus Tricolor ◽  
Core Motif ◽  
Gram Negative ◽  
E Coli ◽  
Membrane Lysis

Abstract Background Plant defensins are a broadly distributed family of antimicrobial peptides which have been primarily studied for agriculturally relevant antifungal activity. Recent studies have probed defensins against Gram-negative bacteria revealing evidence for multiple mechanisms of action including membrane lysis and ribosomal inhibition. Herein, a truncated synthetic analog containing the γ-core motif of Amaranthus tricolor DEF2 (Atr-DEF2) reveals Gram-negative antibacterial activity and its mechanism of action is probed via proteomics, outer membrane permeability studies, and iron reduction/chelation assays. Results Atr-DEF2(G39-C54) demonstrated activity against two Gram-negative human bacterial pathogens, Escherichia coli and Klebsiella pneumoniae. Quantitative proteomics revealed changes in the E. coli proteome in response to treatment of sub-lethal concentrations of the truncated defensin, including bacterial outer membrane (OM) and iron acquisition/processing related proteins. Modification of OM charge is a common response of Gram-negative bacteria to membrane lytic antimicrobial peptides (AMPs) to reduce electrostatic interactions, and this mechanism of action was confirmed for Atr-DEF2(G39-C54) via an N-phenylnaphthalen-1-amine uptake assay. Additionally, in vitro assays confirmed the capacity of Atr-DEF2(G39-C54) to reduce Fe3+ and chelate Fe2+ at cell culture relevant concentrations, thus limiting the availability of essential enzymatic cofactors. Conclusions This study highlights the utility of plant defensin γ-core motif synthetic analogs for characterization of novel defensin activity. Proteomic changes in E. coli after treatment with Atr-DEF2(G39-C54) supported the hypothesis that membrane lysis is an important component of γ-core motif mediated antibacterial activity but also emphasized that other properties, such as metal sequestration, may contribute to a multifaceted mechanism of action.

scholarly journals Leaving the Dark Side? Insights Into the Evolution of Luciferases

2021 ◽  
Vol 8 ◽  
Author(s):  
Jérôme Delroisse ◽  
Laurent Duchatelet ◽  
Patrick Flammang ◽  
Jérôme Mallefet
Keyword(s):  
Literature Review ◽  
Light Emission ◽  
Parallel Evolution ◽  
Dark Side ◽  
Molecular Tools ◽  
Evolutionary Origins ◽  
New Genes ◽  
Luciferase Enzyme ◽  
Living Organisms ◽  
False Idea

Bioluminescence—i.e., the emission of visible light by living organisms—is defined as a biochemical reaction involving, at least, a luciferin substrate, an oxygen derivative, and a specialised luciferase enzyme. In some cases, the enzyme and the substrate are durably associated and form a photoprotein. While this terminology is educatively useful to explain bioluminescence, it gives a false idea that all luminous organisms are using identical or homologous molecular tools to achieve light emission. As usually observed in biology, reality is more complex. To date, at least 11 different luciferins have indeed been discovered, and several non-homologous luciferases lato sensu have been identified which, all together, confirms that bioluminescence emerged independently multiple times during the evolution of living organisms. While some phylogenetically related organisms may use non-homologous luciferases (e.g., at least four convergent luciferases are found in Pancrustacea), it has also been observed that phylogenetically distant organisms may use homologous luciferases (e.g., parallel evolution observed in some cnidarians, tunicates and echinoderms that are sharing a homologous luciferase-based system). The evolution of luciferases then appears puzzling. The present review takes stock of the diversity of known “bioluminescent proteins,” their evolution and potential evolutionary origins. A total of 134 luciferase and photoprotein sequences have been investigated (from 75 species and 11 phyla), and our analyses identified 12 distinct types—defined as a group of homologous bioluminescent proteins. The literature review indicated that genes coding for luciferases and photoproteins have potentially emerged as new genes or have been co-opted from ancestral non-luciferase/photoprotein genes. In this latter case, the homologous gene’s co-options may occur independently in phylogenetically distant organisms.

scholarly journals Micro-nano structured functional coatings deposited by liquid plasma spraying

2020 ◽  
Vol 9 (5) ◽  
pp. 517-534
Author(s):  
Yuchun Huan ◽  
Kaidi Wu ◽  
Changjiu Li ◽  
Hanlin Liao ◽  
Marc Debliquy ◽  
...  
Keyword(s):  
Plasma Spraying ◽  
Structural Characteristics ◽  
Sol Gel ◽  
Chemical Vapor ◽  
Atmospheric Plasma Spraying ◽  
Atmospheric Plasma ◽  
Functional Coatings ◽  
Technical Improvement ◽  
Nano Structure ◽  
Living Organisms

Abstract Inspired by the micro-nano structure on the surface of biological materials or living organisms, micro-nano structure has been widely investigated in the field of functional coatings. Due to its large specific surface area, porosity, and dual-scale structure, it has recently attracted special attention. The typical fabrication processes of micro-nano structured coatings include sol-gel, hydrothermal synthesis, chemical vapor deposition, etc. This paper presents the main features of a recent deposition and synthesis technique, liquid plasma spraying (LPS). LPS is an important technical improvement of atmospheric plasma spraying. Compared with atmospheric plasma spraying, LPS is more suitable for preparing functional coatings with micro-nano structure. Micro-nano structured coatings are mainly classified into hierarchical-structure and binary-structure. The present study reviews the preparation technology, structural characteristics, functional properties, and potential applications of LPS coatings with a micro-nano structure. The micro-nano structured coatings obtained through tailoring the structure will present excellent performances.

A hypothesis: CRISPR-Cas as a minimal cognitive system

2018 ◽  
Vol 27 (3) ◽  
pp. 167-173 ◽  
Author(s):  
Hidetaka Yakura
Keyword(s):  
Nervous System ◽  
Immune System ◽  
Information Integration ◽  
Structural Characteristics ◽  
Explanatory Power ◽  
Cognitive System ◽  
Cognitive Mechanisms ◽  
Recent Developments ◽  
Living Organisms ◽  
Functional Components

Concerning what signifies the minimal requirements for a process to be designated cognitive, various criteria have been proposed, but the problem has not been settled. The important thing to consider in establishing the criteria is which criterion has stronger explanatory power. Recent developments in immunology demonstrate that the immune system is omnipresent in the realm of living beings, including bacteria and archaea. Although the structural characteristics of immune systems are significantly different among species, the fundamental functional components, namely, recognition, information integration, reaction, and memory, are well conserved. Interestingly, these adaptive features are superimposed on those of the central nervous system. Given that adaptive cognitive ability is a prerequisite for the existence and the survival of living organisms, these results may be compatible with the idea that in bacteria without an apparent nervous system, the immune system performs neural-like functions. The presence of the clustered regularly interspaced palindromic repeats (CRISPR)-CRISPR associated protein (Cas) systems as a cognitive system in the earliest living organisms suggests that one of the fundamental functions is conserved throughout evolution. Furthermore, this interpretation can evade the critiques against the current biological paradigm that demand that cognitive mechanisms be preceded by organisms in the earlier stages of evolution, thus providing better and stronger explanatory power. I thus propose that genetic and biochemical machinery represented by the bacterial immune system serves as a minimal cognitive system.

scholarly journals Heparan Sulfate Proteoglycan Signaling in Tumor Microenvironment

2020 ◽  
Vol 21 (18) ◽  
pp. 6588 ◽  
Author(s):  
Valeria De Pasquale ◽  
Luigi Michele Pavone
Keyword(s):  
Tumor Microenvironment ◽  
Heparan Sulfate ◽  
Cancer Progression ◽  
Structural Characteristics ◽  
Tumor Type ◽  
Wide Range ◽  
Functional Features ◽  
Complex Structural ◽  
Tumor Cell Behavior ◽  
Living Organisms

In the last few decades, heparan sulfate (HS) proteoglycans (HSPGs) have been an intriguing subject of study for their complex structural characteristics, their finely regulated biosynthetic machinery, and the wide range of functions they perform in living organisms from development to adulthood. From these studies, key roles of HSPGs in tumor initiation and progression have emerged, so that they are currently being explored as potential biomarkers and therapeutic targets for cancers. The multifaceted nature of HSPG structure/activity translates in their capacity to act either as inhibitors or promoters of tumor growth and invasion depending on the tumor type. Deregulation of HSPGs resulting in malignancy may be due to either their abnormal expression levels or changes in their structure and functions as a result of the altered activity of their biosynthetic or remodeling enzymes. Indeed, in the tumor microenvironment, HSPGs undergo structural alterations, through the shedding of proteoglycan ectodomain from the cell surface or the fragmentation and/or desulfation of HS chains, affecting HSPG function with significant impact on the molecular interactions between cancer cells and their microenvironment, and tumor cell behavior. Here, we overview the structural and functional features of HSPGs and their signaling in the tumor environment which contributes to tumorigenesis and cancer progression.

The rich but confusing terminology of biological nomenclature: a first step towards a comprehensive glossary

Bionomina ◽  
2011 ◽  
Vol 3 (1) ◽  
pp. 63-70
Author(s):  
Alain DUBOIS
Keyword(s):  
Scientific Discipline ◽  
Human Needs ◽  
Higher Taxa ◽  
Unique System ◽  
Basic Need ◽  
The Rich ◽  
Living Organisms ◽  
Protect Study

Biology deals with billions of living organisms, which display a great diversity but also share many characters, being the result of an evolution. Designating these organisms in a universal and unambiguous way is a basic need for communication, not only among taxonomists or even biologists, but with society as a whole. It is indispensable to have a unique system for distinguishing and naming the organisms that may be used for alimentary, agronomical, veterinary or medical purposes or for any other human needs, that may be responsible for diseases, pollutions, biotic invasions, that we may wish to protect, study or admire, etc. For all these purposes, we need a scientific discipline, taxonomy, dealing not only with the classification of living organisms into millions of classificatory units, the taxa, but also with the designation and indexation of these taxa (nomenclature). Biological nomenclature has to care for the scientific naming of millions of taxa (species and higher taxa like genera or families), the inventory of which is still very far from being finished.

scholarly journals What is comparable in comparative cognition?

2012 ◽  
Vol 367 (1603) ◽  
pp. 2677-2685 ◽  
Author(s):  
Lars Chittka ◽  
Stephen J. Rossiter ◽  
Peter Skorupski ◽  
Chrisantha Fernando
Keyword(s):  
Cognitive Functions ◽  
Cognitive Abilities ◽  
Comparative Cognition ◽  
Molecular Genetic ◽  
Parallel Evolution ◽  
Cognitive Capacity ◽  
Genetic Changes ◽  
Hereditary Variation ◽  
The Face ◽  
Cognitive Traits

To understand how complex, or ‘advanced’ various forms of cognition are, and to compare them between species for evolutionary studies, we need to understand the diversity of neural–computational mechanisms that may be involved, and to identify the genetic changes that are necessary to mediate changes in cognitive functions. The same overt cognitive capacity might be mediated by entirely different neural circuitries in different species, with a many-to-one mapping between behavioural routines, computations and their neural implementations. Comparative behavioural research needs to be complemented with a bottom-up approach in which neurobiological and molecular-genetic analyses allow pinpointing of underlying neural and genetic bases that constrain cognitive variation. Often, only very minor differences in circuitry might be needed to generate major shifts in cognitive functions and the possibility that cognitive traits arise by convergence or parallel evolution needs to be taken seriously. Hereditary variation in cognitive traits between individuals of a species might be extensive, and selection experiments on cognitive traits might be a useful avenue to explore how rapidly changes in cognitive abilities occur in the face of pertinent selection pressures.

scholarly journals Engineering of Marine-derived Antimicrobial Peptides (mAMPs) into Improved Anti-infective Drug Leads: A Mini-review

2021 ◽  
Vol 1192 (1) ◽  
pp. 012013
Author(s):  
L Sukmarini
Keyword(s):  
Antimicrobial Peptides ◽  
Chemical Diversity ◽  
Cytotoxic Activities ◽  
Small Molecular Weight ◽  
Resistance Development ◽  
Drug Candidates ◽  
Bacteria And Fungi ◽  
Drug Leads ◽  
Net Positive Charge

Abstract Marine-derived antimicrobial compounds possess chemical diversity varying from peptides, fatty acids to terpenes, alkaloids, and polyketides. These compounds, especially of peptide origin called antimicrobial peptides (AMPs), are present in the majority of marine organisms, including microbes (bacteria and fungi), invertebrates (molluscs, echinoderms, and sponges), vertebrates (fish and mammals), and plants (marine algae). They are defined by small molecular weight (less than 10 kDa), a net positive charge, and amphipathic structures. Moreover, due to their profound in vitro antimicrobial and cytotoxic activities and a low risk for resistance development, naturally occurring marine-derived AMPs (mAMPs) have been used as drug design templates for a large variety of semi-synthetic or synthetic AMPs, some of which have reached clinical trials. This mini-review aims to discuss AMPs from marine sources, mainly emphasizing the engineering of these peptides with improved pharmacological properties to develop drug candidates. Some selected recent examples of these engineered mAMPs as anti-infective drug leads are herein highlighted.

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