A novel horse α-defensin: gene transcription, recombinant expression and characterization of the structure and function

Defensins are a predominant class of antimicrobial peptides, which act as endogenous antibiotics. Defensins are classified into three distinct sub-families: θ-, β-, and α-defensins. Synthesis of α-defensin has been confirmed only in primates and glires to date and is presumably unique for a few tissues, including neutrophils and Paneth cells of the small intestine. Antimicrobial activities of these peptides were shown against a wide variety of microbes including bacteria, fungi, viruses and protozoan parasites. In the present study, we report the characterization of the equine α-defensin DEFA (defensin α) 1. Transcription analysis revealed that the transcript of the gene is present in the small intestine only. An alignment with known α-defensins from primates and glires displayed a homology with Paneth-cell-specific α-defensins. DEFA1 was recombinantly expressed in Escherichia coli and subsequently analysed structurally by CD and molecular modelling. To examine the antimicrobial properties, a radial diffusion assay was performed with 12 different micro-organisms and the LD90 (lethal dose killing ≥90% of target organism) and MBC (minimal bactericidal concentration) values were examined. DEFA1 showed an antimicrobial activity against different Gram-positive and Gram-negative bacteria and against the yeast Candida albicans. Using viable bacteria in combination with a membrane-impermeable fluorescent dye, as well as depolarization of liposomes as a minimalistic system, it became evident that membrane permeabilization is at least an essential part of the peptide's mode of action.

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Isolation and Characterization of Soil Myxobacteria from Nepal

Journal of Institute of Science and Technology ◽

10.3126/jist.v24i2.27246 ◽

2019 ◽

Vol 24 (2) ◽

pp. 7-16

Author(s):

Nabin Rana ◽

Saraswoti Khadka ◽

Bishnu Prasad Marasini ◽

Bishnu Joshi ◽

Pramod Poudel ◽

...

Keyword(s):

Sequence Similarity ◽

Antimicrobial Properties ◽

Antimicrobial Activities ◽

Rrna Gene ◽

Isolation And Characterization ◽

The Family ◽

Global Concern ◽

Bacteria And Fungi ◽

Antimicrobial Metabolites

Realizing myxobacteria as a potential source of antimicrobial metabolites, we pursued research to isolate myxobacteria showing antimicrobial properties. We have successfully isolated three strains (NR-1, NR-2, NR-3) using the Escherichia coli baiting technique. These isolates showed typical myxobacterial growth characteristics. Phylogenetic analysis showed that all the strains (NR-1, NR-2, NR-3) belong to the family Archangiaceae, suborder Cystobacterineae, and order Myxococcales. Furthermore, 16S rRNA gene sequence similarity searched through BLAST revealed that strain NR-1 showed the closest similarity (91.8 %) to the type strain Vitiosangium cumulatum (NR-156939), NR-2 showed (98.8 %) to the type of Cystobacter badius (NR-043940), and NR-3 showed the closest similarity (83.5 %) to the type of strain Cystobacter fuscus (KP-306730). All isolates showed better growth in 0.5-1 % NaCl and pH around 7.0, whereas no growth was observed at pH 9.0 and below 5.0. All strains showed better growth at 32° C and hydrolyzed starch, whereas casein was efficiently hydrolyzed by NR-1 and NR-2. Besides, preliminary antimicrobial tests from crude extracts showed activities against Gram-positive, Gram-negative bacteria, and fungi. Our findings suggest that the arcane soil habitats of Nepal harbor myxobacteria with the capability to produce diverse antimicrobial activities that may be explored to overcome the rapidly rising global concern about antibiotic resistance.

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Characterization of microemulsions formulated from naturally and chemically extracted oils from Cocos nucifera Linne

Nigerian Journal of Pharmaceutical Research ◽

10.4314/njpr.v16i1.5 ◽

2020 ◽

Vol 16 (1) ◽

pp. 39-48

Author(s):

O.A. Adetunji ◽

B. Adesanwo ◽

O.A. Odeniyi

Keyword(s):

Castor Oil ◽

Cocos Nucifera ◽

Antimicrobial Properties ◽

Coconut Oil ◽

Tween 80 ◽

Antimicrobial Activities ◽

Oil Extraction ◽

Hot Water ◽

Copper Zinc

Background: Oil derived from Cocos nucifera Linne (CNL) has been used in formulating creams; however, its use in formulation of microemulsion is not well documented in literature.Objective: Oils obtained from CNL were characterized, used in the formulation of microemulsions and were evaluated for their antimicrobial properties in comparison with Castor oil BP (CO) and commercially available coconut oil (CACO).Methodology: Oil from CNL was extracted by maceration in hot – water and petroleum ether to yield naturally extracted oil (NEO) and chemically extracted oil (CEO) respectively. The NEO and CEO were used in formulating microemulsions containing pre-determined ratios (3:7, 1:1, 9:1) of oil to surfactant mix (Smix) [containing polyethylene glycol: Tween 80® at ratio 2:1] Characterization of NEO, CEO and microemulsions were carried out using elemental constituents, rheology, physico-and phyto-chemical analysis, thermal stability and antimicrobial profiles as parameters. Statistical analysis was done using ANOVA at p<0.05Results: The NEO and CEO contained antraquinones and terpenoids, but were devoid of lead, copper, zinc, alkaloids, saponins, cardiac glycosides and flavonoids. Viscosity profiles were in the order CO>CEO>CACO>NEO. The microemulsions were in the size range 54.24±0.26-89.08±0.07 μm. Microemulsions of oil:Smix (3:7) were the most stable. Inhibition ranking was Candida sp.D25 (CEO:Smix>CACO: Smix>NEO: Smix>NEO>CO>CEO), Candida sp.D33 (CEO = CO>CACO: Smix=NEO>CEO:Smix=NEO:Smix), Staphylococcus sp.DS2 (NEO>CO>CACO:Smix>NEO: Smix>CEO: Smix=CEO) and Pseudomonas sp.DP8 (NEO:Smix>CO>CACO:Smix>CEO:Smix=NEO > CEO).Conclusion: Oil derived from CNL has good potentials as an excipient in the formulation of microemulsions and the method of oil extraction had a significant effect on the antimicrobial activities and on the microemulsions formulated using the oils. Keywords: Coconut oil, extraction method, castor oil, microemulsions, antimicrobial properties.

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The human small intestine comprises two subsets of regulatory Foxp3+ CD4 T cells with very different life span and functional properties

10.1101/2020.02.12.941369 ◽

2020 ◽

Author(s):

Sudhir Kumar Chauhan ◽

Raquel Bartolomé Casado ◽

Ole J.B. Landsverk ◽

Jørgen Jahnsen ◽

Rune Horneland ◽

...

Keyword(s):

T Cells ◽

Small Intestine ◽

Cd4 T Cells ◽

Post Transplantation ◽

Human Small Intestine ◽

Dietary Antigens ◽

Low Levels ◽

Contrast Information ◽

And Function

ABSTRACTGut resident regulatory CD4+ T (Tregs) cells in mice are mainly specific for intestinal antigens and play an important role in the suppression of immune responses against harmless dietary antigens and the gut microbiota. In contrast, information about the phenotype and function of Tregs in the human gut is limited. Here, we performed a detailed characterization of Foxp3+ CD4 Tregs in human small intestine (SI). SI Foxp3+ CD4 T cells were CD45RA-CTLA4+CD127- and suppressed proliferation of autologous T cells. Approximately 60% of SI Tregs expressed the transcription factor Helios. When stimulated, Helios- Tregs produced IL-17, IFNγ and IL-10, whereas Helios+ Tregs produced very low levels of these cytokines. Sampling mucosal tissue from transplanted human duodenum we demonstrated that donor SI Helios+ Tregs have a rapid turnover rate whereas Helios- Tregs persisted for at least 1 yr post transplantation. In the normal SI, Foxp3+ Tregs constituted only 2% of all CD4 T cells, while in active celiac disease both subsets expanded 5-10-fold. Taken together, these findings suggest that human SI contains two phenotypically and functionally distinct Treg subsets (Helios+ and Helios- Tregs), which are reminiscent of rapidly renewed dietary antigen-specific Tregs and microbiota-specific Tregs resident in the mouse gut, respectively.

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Recent Advances in the Discovery and Function of Antimicrobial Molecules in Platelets

International Journal of Molecular Sciences ◽

10.3390/ijms221910230 ◽

2021 ◽

Vol 22 (19) ◽

pp. 10230

Author(s):

Alba S. Aquino-Domínguez ◽

María de los A. Romero-Tlalolini ◽

Honorio Torres-Aguilar ◽

Sergio R. Aguilar-Ruiz

Keyword(s):

Antimicrobial Properties ◽

Human Platelets ◽

Rabbit Serum ◽

Functional Evaluation ◽

Host Defense Peptides ◽

Vascular Integrity ◽

Activated Platelets ◽

And Function ◽

Identification And Characterization

The conventional function described for platelets is maintaining vascular integrity. Nevertheless, increasing evidence reveals that platelets can additionally play a crucial role in responding against microorganisms. Activated platelets release molecules with antimicrobial activity. This ability was first demonstrated in rabbit serum after coagulation and later in rabbit platelets stimulated with thrombin. Currently, multiple discoveries have allowed the identification and characterization of PMPs (platelet microbicidal proteins) and opened the way to identify kinocidins and CHDPs (cationic host defense peptides) in human platelets. These molecules are endowed with microbicidal activity through different mechanisms that broaden the platelet participation in normal and pathologic conditions. Therefore, this review aims to integrate the currently described platelet molecules with antimicrobial properties by summarizing the pathways towards their identification, characterization, and functional evaluation that have promoted new avenues for studying platelets based on kinocidins and CHDPs secretion.

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New Alkenylresorcinols with Cytotoxic and Antimicrobial Activities from the Leaves of Embelia schimperi

Planta Medica ◽

10.1055/a-1209-3501 ◽

2020 ◽

Vol 86 (17) ◽

pp. 1298-1303

Author(s):

Tatiana Arlette M. Togue ◽

Blanche Laure Ndontsa ◽

Gabin Thierry M. Bitchagno ◽

Anja Schüffler ◽

Till Opatz ◽

...

Keyword(s):

Antimicrobial Properties ◽

Antimicrobial Activities ◽

Spectroscopic Techniques ◽

Ongoing Research ◽

Phytochemical Study ◽

Phenolic Lipids ◽

Cervical Cancer Cells ◽

Hela S3 ◽

Human Cervical Cancer Cells

AbstractA phytochemical study of the methanol extract of the leaves of Embelia schimperi resulted in the isolation of three new alkenylresorcinols, 1 – 3, together with the known analogs 4 – 7. Their structures were established by a combination of spectroscopic techniques. Compounds 1 – 7 exhibited moderate cytotoxic activity against human cervical cancer cells HeLa-S3 and more pronounced antimicrobial properties towards bacteria and filamentous fungi. The present study falls into an ongoing research project on the characterization of bioactive phenolic lipids from plants of the family Primulaceae.

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Thrittene, Homologous with Somatostatin-28(1–13), Is a Novel Peptide in Mammalian Gut and Circulation

Endocrinology ◽

10.1210/endo.143.7.8904 ◽

2002 ◽

Vol 143 (7) ◽

pp. 2599-2609 ◽

Cited By ~ 7

Author(s):

John W. Ensinck ◽

Denis G. Baskin ◽

Torsten P. Vahl ◽

Robin E. Vogel ◽

Ellen C. Laschansky ◽

...

Keyword(s):

Small Intestine ◽

Endocrine Cells ◽

Intestinal Tract ◽

Proximal Region ◽

Targeted Deletion ◽

C Terminus ◽

D Cells ◽

And Function ◽

Somatostatin 14

Abstract Preprosomatostatin is a gene expressed ubiquitously among vertebrates, and at least two duplications of this gene have occurred during evolution. Somatostatin-28 (S-28) and somatostatin-14 (S-14), C-terminal products of prosomatostatin (ProS), are differentially expressed in mammalian neurons, d cells, and enterocytes. One pathway for the generation of S-14 entails the excision of Arg13-Lys14 in S-28, leading to equivalent amounts of S-28(1–12). Using an antiserum (F-4), directed to the N-terminal region of S-28 that does not react with S-28(1–12), we detected a peptide, in addition to S-28 and ProS, that was present in human plasma and in the intestinal tract of rats and monkeys. This F-4 reacting peptide was purified from monkey ileum; and its amino acid sequence, molecular mass, and chromatographic characteristics conformed to those of S-28(1–13), a peptide not described heretofore. When extracts of the small intestine were measured by RIA, there was a discordance in the ratio of peptides reacting with F-4 and those containing the C terminus of ProS, suggesting sites of synthesis for S-28(1–13) distinct from those for S-14 and S-28. This was supported by immunocytochemistry, wherein F-4 reactivity was localized in gastrointestinal (GI) endocrine cells and a widespread plexus of neurons within the wall of the distal gut while immunoreactivity to C-terminal domains of S-14 and S-28 in these neurons was absent. Further, F-4 immunoreactivity persisted in similar GI endocrine cells and myenteric neurons in mice with a targeted deletion of the preprosomatostatin gene. We believe that these data suggest a novel peptide produced in the mammalian gut, homologous with the 13 residues of the proximal region of S-28 but not derived from the ProS gene. Pending characterization of the gene from which this peptide is derived, its distribution, and function, we have designated this peptide as thrittene. Its localization in both GI endocrine cells and gut neurons suggests that thrittene may function as both a hormone and neurotransmitter.

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Gene structure, recombinant expression and function characterization of Siniperca chuatsi Fsrp‐3

Journal of Fish Biology ◽

10.1111/jfb.13931 ◽

2019 ◽

Vol 94 (5) ◽

pp. 714-724

Author(s):

Jianhua Wang ◽

Jia Cheng ◽

Yulong Li ◽

Huiling Yan ◽

Ping Wu ◽

...

Keyword(s):

Gene Structure ◽

Recombinant Expression ◽

Siniperca Chuatsi ◽

Function Characterization ◽

And Function

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Synthesis and Characterization of Chemical Structures, Thermal Decomposition and Biological Properties of Novel Copper (II) Bio- Based Surfactants

Current Physical Chemistry ◽

10.2174/1877946810666200116091321 ◽

2020 ◽

Vol 10 (3) ◽

pp. 213-228

Author(s):

Asha Meena ◽

Rashmi Sharma ◽

Vandana Sukhadia

Keyword(s):

Staphylococcus Aureus ◽

Thermal Degradation ◽

Edible Oils ◽

Waste Water Treatment ◽

Antimicrobial Properties ◽

Antimicrobial Activities ◽

Biological Properties ◽

Synthesis And Characterization ◽

Chemical Structures

Background: Thermal degradation has attracted the attention of scientific community throughout the world due to its multiple applications in environment, energy, waste water treatment, pollution control, green chemistry, etc. Objective: The present work deals with the study of synthesis and characterization of thermal and biological properties of novel copper complex. Methods: Chemical structures of copper (II) sesame 2-amino-6-ethoxy benzothiazole complex were confirmed by IR, NMR, and ESR techniques. Thermal and biological properties were analysed by Thermogravimetry (TGA) and antimicrobial activity determination against Staphylococcus aureus. Results: The TGA study reveals that copper (II) sesame 2-amino-6-ethoxy benzothiazole complex undergoes stepwise thermal degradation of ligand-soap bond of complex and unsaturated and saturated fatty acid components of edible oils. The complex exhibit significant antimicrobial activities against Staphylococcus aureus. Conclusion: This study provides relevant basic information on the thermal and antimicrobial properties of new copper (II) bio-based surfactants, as well as an explicit relationship structure-biological activity for their potential use as safe and green chemicals.

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