cDNA cloning and functional characterisation of four antimicrobial peptides from Paa spinosa

2015 ◽  
Vol 70 (9-10) ◽  
pp. 251-256 ◽  
Author(s):  
Bao Juan Dong ◽  
Zhong Gen Zhan ◽  
Rong Quan Zheng ◽  
Wen Chen ◽  
Jin Jin Min
Keyword(s):  
Antimicrobial Peptides ◽  
Chemical Properties ◽  
Antimicrobial Activities ◽  
Innate Immune ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Small Peptides ◽  
Future Design ◽  
Functional Characterisation ◽  
Race Technique

Abstract Antimicrobial peptides (AMPs) are small peptides found in many organisms defending themselves against pathogens. AMPs form the first line of host defence against pathogenic infections and are key components of the innate immune system of amphibians. In the current study, cDNAs of precursors of four novel antimicrobial peptides in the skin of Paa spinosa were cloned and sequenced using the 3′-RACE technique. Mature peptides, named spinosan A–D, encoded by the cDNAs were chemically synthesized and their chemical properties were predicted. The antimicrobial, antioxidative, cyotoxic and haemolytic activities of these four AMPs were determined. While the synthesised spinosans A–C exhibited no activity towards any of the bacterial strains tested, spinosan-D exhibited weak but broad-spectrum antimicrobial activities against Gram-positive and Gram-negative bacteria. All peptides were weakly haemolytic towards rabbit erythrocytes, had a strong antioxidative activity, and a low cytotoxic activity against HeLa cells. These findings provide helpful insights that may be useful in the future design of anti-infective peptide agents.

scholarly journals STUDY ON ANTI-MICROBIAL PROPERTIES OF Enicosanthum membranifolium SINCLAIR AND Enicosanthum cupulare (KING) AIRY-SHAW

2015 ◽  
Vol 3 (1) ◽  
pp. 62
Author(s):  
Mai Efdi ◽  
Mamoru Koketsu ◽  
Kunitomo Watanabe ◽  
Nurainas
Keyword(s):  
Ethyl Acetate ◽  
Inhibitory Concentration ◽  
Ethyl Acetate Fraction ◽  
Antimicrobial Activities ◽  
Dilution Method ◽  
Agar Dilution Method ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Microbial Properties ◽  
Agar Dilution

 ABSTRACT n-Hexane and ethyl acetate fractions of methanol extracts of two species of Annonaceae, Enicosanthum membranifolium Sinclair and Enicosanthum cupulare (King) Airy-Shaw, were screened for antimicrobial activity against eighteen bacterial strains using agar dilution method. The ethyl acetate fraction of the two Annonaceae plants showed higher antimicrobial activities than the n-hexane fraction. The extracts of the plants tested were significantly more active against gram-positive with minimum inhibitory concentration (MICs) ranging from 0.0625 to 4 mg/mL than against gram negative bacteria (MICs >4 mg/mL). Keywords: Antibacterial activity; Enicosanthum membranifolium Sinclair; Enicosanthum cupulare (King) Airy-Shaw

scholarly journals Synthesis and antimicrobial activity of some new N-(aryl-oxo-alkyl)-5-arylidene-thiazolidine-2,4-diones

2014 ◽  
Vol 79 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Anca Stana ◽  
Brînduşa Tiperciuc ◽  
Mihaela Duma ◽  
Adrian Pîrnău ◽  
Philippe Verité ◽  
...  
Keyword(s):  
Antimicrobial Activities ◽  
Fungal Strain ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Reference Drug ◽  
Gram Negative ◽  
E Coli ◽  
Inhibitory Activities

A series of new 5-(2,6-dichlorobenzylidene)thiazolidine-2,4-dione and 5-(4-methoxy-benzylidene)thiazolidine-2,4-dione derivatives (3a-h and 5a-h) were synthesized starting from 5-arylidene-thiazolidine-2,4-dione and ?-halo-ketones. The structural elucidation of the newly synthesized compounds was based on elemental analysis and spectroscopic data (MS, 1H-NMR, 13C-NMR). The synthesized compounds were screened for their antimicrobial activities against several pathogenic strains of Gram-positive and Gram-negative bacteria and one fungal strain (Candida albicans), assessed in vitro as growth inhibition diameters. Some of them displayed better inhibitory activities than that of the reference drug against the Gram-positive S. aureus, B. cereus, L. monocytogenes bacterial strains, and showed good antifungal activity against C. albicans, while the antibacterial activity against Gram-negative E. coli and S. typhimurium bacterial strains was moderate.

Discovery of novel antimicrobial peptides: A transcriptomic study of the sea anemone Cnidopus japonicus

2018 ◽  
Vol 16 (02) ◽  
pp. 1840006 ◽  
Author(s):  
Ekaterina N. Grafskaia ◽  
Nadezhda F. Polina ◽  
Vladislav V. Babenko ◽  
Daria D. Kharlampieva ◽  
Pavel A. Bobrovsky ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Peptides ◽  
Search Algorithm ◽  
Sea Anemone ◽  
Amino Acid Sequences ◽  
Innate Immune ◽  
Bacterial Strains ◽  
Wide Range ◽  
Structural Peculiarities ◽  
Living Organisms

As essential conservative component of the innate immune systems of living organisms, antimicrobial peptides (AMPs) could complement pharmaceuticals that increasingly fail to combat various pathogens exhibiting increased resistance to microbial antibiotics. Among the properties of AMPs that suggest their potential as therapeutic agents, diverse peptides in the venoms of various predators demonstrate antimicrobial activity and kill a wide range of microorganisms. To identify potent AMPs, the study reported here involved a transcriptomic profiling of the tentacle secretion of the sea anemone Cnidopus japonicus. An in silico search algorithm designed to discover toxin-like proteins containing AMPs was developed based on the evaluation of the properties and structural peculiarities of amino acid sequences. The algorithm revealed new proteins of the anemone containing antimicrobial candidate sequences, and 10 AMPs verified using high-throughput proteomics were synthesized. The antimicrobial activity of the candidate molecules was experimentally estimated against Gram-positive and -negative bacteria. Ultimately, three peptides exhibited antimicrobial activity against bacterial strains, which suggests that the method can be applied to reveal new AMPs in the venoms of other predators as well.

Human Oral Defensins Antimicrobial Peptides: A Future Promising Antimicrobial Drug

2018 ◽  
Vol 24 (10) ◽  
pp. 1130-1137 ◽  
Author(s):  
Zohaib Khurshid ◽  
Muhammad S. Zafar ◽  
Mustafa Naseem ◽  
Rabia Sannam Khan ◽  
Shariq Najeeb
Keyword(s):  
Antimicrobial Peptides ◽  
English Language ◽  
Clinical Importance ◽  
Innate Immune ◽  
Gram Negative Bacteria ◽  
Disulphide Bridge ◽  
Research Papers ◽  
Gram Negative ◽  
Human Defensins ◽  
Unique Amino Acid

The nature and structural composition of antimicrobial peptides are derived from their innate immune response and they are active against various bacteria, fungi and other microorganisms. The aim of this paper was to pool up the literature on the features of human oral defensins antimicrobial peptides. The defensins showed antimicrobial activity against Gram-positive and Gram-negative bacteria and various fungi and viruses. As with their other properties like antiviral, antifungal and antibacterial, human defensins peptides are thought to have a unique amino acid-based structure with Disulphide Bridge which makes them synthesize chemically or naturally with the help of these bacteria. The data contributing in this study was gathered from the research papers published in English language in the last twenty-five years. This literature mainly elaborates the general and analytical characteristics of antimicrobial peptides in the human oral cavity; focusing on the types, biochemistry, and mechanism of action of defensins with its clinical importance.

scholarly journals Development of a novel antimicrobial peptide AWRK6

2016 ◽  
Vol 11 (2) ◽  
pp. 460 ◽  
Author(s):  
Dusik  Kim ◽  
Zheng  Wang ◽  
Lili  Jin ◽  
Hanpin  Li ◽  
Junwei  Hwang ◽  
...  
Keyword(s):  
Antimicrobial Peptide ◽  
Antimicrobial Activities ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Negative ◽  
Killing Rate ◽  
Physiological Conditions ◽  
Alkaline Environments ◽  
Improved Stability ◽  
Rana Dybowskii

<p class="Abstract">We have previously identified an antimicrobial peptide called dybowskin2-CDYa (Dy2) in the cutaneous secretion from the Chinese frog Rana dybowskii. In this study, we used Dy2 as a template to prepare some novel peptides with improved stability and hydrophobicity. The antimicrobial activities exerted by these peptides against Gram positive and Gram negative bacteria were evaluated by MIC and CFU assays under physiological conditions. One peptide, AWRK6, was 2-4 fold more potent than Dy2, and was toxic to most of the bacterial strains tested, exhibiting a faster killing rate.  AWRK6 was most potent in alkaline environments, and this was related to the more highly organized secondary structure of the peptide, as revealed by circular dichroism spectroscopy. Furthermore, AWRK6 was more resistant than Dy2 to degradation by trypsin. The improved properties of AWRK6 suggested that the peptide could potentially be further developed into an antibiotic.</p><p> </p>

scholarly journals Novel Antimicrobial Peptides Derived from Flatfish Genes

2003 ◽  
Vol 47 (8) ◽  
pp. 2464-2470 ◽  
Author(s):  
Aleksander Patrzykat ◽  
Jeffrey W. Gallant ◽  
Jung-Kil Seo ◽  
Jennifer Pytyck ◽  
Susan E. Douglas
Keyword(s):  
Antimicrobial Peptides ◽  
Antimicrobial Activities ◽  
Resistant Organism ◽  
Gram Negative Bacteria ◽  
Genomic Information ◽  
Carboxy Terminus ◽  
Antibiotic Resistant ◽  
Active Peptides ◽  
Flanking Sequences ◽  
Flanking Regions

ABSTRACT We report on the identification of active novel antimicrobials determined by screening both the genomic information and the mRNA transcripts from a number of different flatfish for sequences encoding antimicrobial peptides, predicting the sequences of active peptides from the genetic information, producing the predicted peptides chemically, and testing them for their activities. We amplified 35 sequences from various species of flatfish using primers whose sequences are based on conserved flanking regions of a known antimicrobial peptide from winter flounder, pleurocidin. We analyzed the sequences of the amplified products and predicted which sequences were likely to encode functional antimicrobial peptides on the basis of charge, hydrophobicity, relation to flanking sequences, and similarity to known active peptides. Twenty peptides were then produced synthetically and tested for their activities against gram-positive and gram-negative bacteria and the yeast Candida albicans. The most active peptide (with the carboxy-terminus amidated sequence GWRTLLKKAEVKTVGKLALKHYL, derived from American plaice) showed inhibitory activity over a concentration range of 1 to 8 μg/ml against a test panel of pathogens, including the intrinsically antibiotic-resistant organism Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus, and C. albicans. The methods described here will be useful for the identification of novel peptides with good antimicrobial activities.

scholarly journals A Brief Review on the Antioxidants and Antimicrobial Peptides Revealed in Mud Crabs from the Genus of Scylla

2017 ◽  
Vol 2017 ◽  
pp. 1-7
Author(s):  
Wan Roslina Wan Yusof ◽  
Fasihuddin Badruddin Ahmad ◽  
Mummedy Swamy
Keyword(s):  
Antimicrobial Peptides ◽  
Antioxidant Properties ◽  
Antimicrobial Properties ◽  
Antimicrobial Activities ◽  
Biological Properties ◽  
Gram Negative Bacteria ◽  
Mud Crab ◽  
Mangrove Crab ◽  
Aquaculture Industry ◽  
Mud Crabs

Mud crab from the genus Scylla is also known as mangrove crab, which has been well-accepted as a good source of protein. Recently, the antioxidant properties present in mud crabs have been reported to have a part in the protection of cells against free radicals. Meanwhile, numerous antimicrobial peptides from mud crabs have managed to be characterized through the display of antimicrobial activities against Gram-positive and Gram-negative bacteria. Hence, this paper is an effort to collect recent literatures on antioxidant and antimicrobial properties in every part of mud crabs which include muscle tissue, hemolymph, and crab shell. Moreover, the effort to understand the biological properties of mud crabs is important to enhance its production in aquaculture industry. Therefore, this review hoped to attract the attention of natural product researchers to focus on the potential therapeutic applications of mud crabs.

scholarly journals In VitroandIn VivoActivities of Antimicrobial Peptides Developed Using an Amino Acid-Based Activity Prediction Method

2014 ◽  
Vol 58 (9) ◽  
pp. 5342-5349 ◽  
Author(s):  
Xiaozhe Wu ◽  
Zhenling Wang ◽  
Xiaolu Li ◽  
Yingzi Fan ◽  
Gu He ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Amino Acid ◽  
Antimicrobial Peptides ◽  
Bacterial Load ◽  
Prediction Method ◽  
Multidrug Resistant ◽  
Antimicrobial Activities ◽  
Bacterial Strains ◽  
Content Type

ABSTRACTTo design and discover new antimicrobial peptides (AMPs) with high levels of antimicrobial activity, a number of machine-learning methods and prediction methods have been developed. Here, we present a new prediction method that can identify novel AMPs that are highly similar in sequence to known peptides but offer improved antimicrobial activity along with lower host cytotoxicity. Using previously generated AMP amino acid substitution data, we developed an amino acid activity contribution matrix that contained an activity contribution value for each amino acid in each position of the model peptide. A series of AMPs were designed with this method. After evaluating the antimicrobial activities of these novel AMPs against both Gram-positive and Gram-negative bacterial strains, DP7 was chosen for further analysis. Compared to the parent peptide HH2, this novel AMP showed broad-spectrum, improved antimicrobial activity, and in a cytotoxicity assay it showed lower toxicity against human cells. Thein vivoantimicrobial activity of DP7 was tested in aStaphylococcus aureusinfection murine model. When inoculated and treated via intraperitoneal injection, DP7 reduced the bacterial load in the peritoneal lavage solution. Electron microscope imaging and the results indicated disruption of theS. aureusouter membrane by DP7. Our new prediction method can therefore be employed to identify AMPs possessing minor amino acid differences with improved antimicrobial activities, potentially increasing the therapeutic agents available to combat multidrug-resistant infections.

Antimicrobial Activity of Iron-Halide Complexes Against Gram-Positive and Gram-Negative Bacteria

2020 ◽  
Author(s):  
Nusrat Abedin ◽  
Abdullah Hamed A Alshehri ◽  
Ali M A Almughrbi ◽  
Olivia Moore ◽  
Sheikh Alyza ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antimicrobial Resistance ◽  
Extracellular Dna ◽  
Antibiofilm Activity ◽  
Gram Negative Bacteria ◽  
Bacterial Strains ◽  
Gram Positive ◽  
Gram Negative ◽  
Antimicrobial Substances ◽  
Mammalian Cell Lines

Antimicrobial resistance (AMR) has become one of the more serious threats to the global health. The emergence of bacteria resistant to antimicrobial substances decreases the potencies of current antibiotics. Consequently, there is an urgent and growing need for the developing of new classes of antibiotics. Three prepared novel iron complexes have a broad-spectrum antimicrobial activity with minimum bactericidal concentration (MBC) values ranging from 3.5 to 10 mM and 3.5 to 40 mM against Gram-positive and Gram-negative bacteria with antimicrobial resistance phenotype, respectively. Time-kill studies and quantification of the extracellular DNA confirmed the bacteriolytic mode of action of the iron-halide compounds. Additionally, the novel complexes showed significant antibiofilm activity against the tested pathogenic bacterial strains at concentrations lower than the MBC. The cytotoxic effect of the complexes on different mammalian cell lines show sub-cytotoxic values at concentrations lower than the minimum bactericidal concentrations.

Study of Physico-chemical Characteristics and Pharmacological Effects of 1-Ethyl-Salicyldene-bis-Ethylene-Diamine and Its Complex with Mn(II)

2019 ◽  
Vol 70 (7) ◽  
pp. 2534-2537
Author(s):  
Gladiola Tantaru ◽  
Mihai Apostu ◽  
Antonia Poiata ◽  
Mihai Nichifor ◽  
Nela Bibire ◽  
...  
Keyword(s):  
Schiff Base ◽  
Chemical Structure ◽  
Antimicrobial Activities ◽  
Ethylene Diamine ◽  
Chemical Characteristics ◽  
Gram Negative Bacteria ◽  
Pharmacological Effects ◽  
Physico Chemical ◽  
Anti Inflammatory ◽  
Inflammatory Effect

The paper presents the synthesis of a new complex combination of a Bis-Schiff base with Mn(II) ions with great potential for antimicrobial and anti-inflammatory activity. A new complex of the Salen-type ligand, 1-ethyl-salicylidene-bis-ethylene diamine was synthetized using Mn(II) ions. The chemical structure was confirmed through 1H-NMR and IR spectroscopy. The antimicrobial activities of the Bis-Schiff base and its complex were tested in comparison with Ampicillin, Chloramphenicol, Tetracycline, Ofloxacin and Nystatin. Those compounds were found to be active against Gram-positive or Gram-negative bacteria, and had an anti-inflammatory effect comparable to that of Indomethacin.

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