NMR Assisted Antimicrobial Peptide Designing: Structure Based Modifications and Functional Correlation of a Designed Peptide VG16KRKP

2020 ◽  
Vol 27 (9) ◽  
pp. 1387-1404 ◽  
Author(s):  
Karishma Biswas ◽  
Humaira Ilyas ◽  
Aritreyee Datta ◽  
Anirban Bhunia
Keyword(s):  
Antimicrobial Agents ◽  
Biological Properties ◽  
Structure Characterization ◽  
Drug Resistant ◽  
Functional Correlation ◽  
Naturally Occurring ◽  
High Resolution Nmr ◽  
Different Types ◽  
Reduced Activity ◽  
Poor Stability

Antimicrobial Peptides (AMPs), within their realm incorporate a diverse group of structurally and functionally varied peptides, playing crucial roles in innate immunity. Over the last few decades, the field of AMP has seen a huge upsurge, mainly owing to the generation of the so-called drug resistant ‘superbugs’ as well as limitations associated with the existing antimicrobial agents. Due to their resilient biological properties, AMPs can very well form the sustainable alternative for nextgeneration therapeutic agents. Certain drawbacks associated with existing AMPs are, however, issues of major concern, circumventing which are imperative. These limitations mainly include proteolytic cleavage and hence poor stability inside the biological systems, reduced activity due to inadequate interaction with the microbial membrane, and ineffectiveness because of inappropriate delivery among others. In this context, the application of naturally occurring AMPs as an efficient prototype for generating various synthetic and designed counterparts has evolved as a new avenue in peptide-based therapy. Such designing approaches help to overcome the drawbacks of the parent AMPs while retaining the inherent activity. In this review, we summarize some of the basic NMR structure based approaches and techniques which aid in improving the activity of AMPs, using the example of a 16-residue dengue virus fusion protein derived peptide, VG16KRKP. Using first principle based designing technique and high resolution NMR-based structure characterization we validate different types of modifications of VG16KRKP, highlighting key motifs, which optimize its activity. The approaches and designing techniques presented can support our peers in their drug development work.

Human Neuraminidases Have Reduced Activity Towards Modified Sialic Acids on Glycoproteins

2020 ◽  
Author(s):  
Carmanah D. Hunter ◽  
Elizabeth Porter ◽  
Christopher Cairo
Keyword(s):  
Substrate Specificity ◽  
General Trend ◽  
Sialic Acids ◽  
Enzyme Specificity ◽  
Naturally Occurring ◽  
Bovine Submaxillary Mucin ◽  
Reduced Activity

This work investigated the substrate specificity of hNEU enzymes for a glycoprotein substrate (bovine submaxillary mucin) containing 9-<i>O</i>-acetylated and Neu5Gc residues. Using this model substrate, we observe a general trend for hNEU tolerance of Neu5Ac>Neu5Gc>>>Neu5,9Ac<sub>2</sub>, consistent with our previous results with glycolipid substrates. These results expand our understanding of hNEU enzyme specificity and suggest that naturally occurring modifications of sialic acids can play a role in regulating hNEU activity.

Inorganic Gold and Polymeric Poly(Lactide-co-glycolide) Nanoparticles as Novel Strategies to Ameliorate the Biological Properties of Antimicrobial Peptides

2020 ◽  
Vol 21 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Bruno Casciaro ◽  
Francesca Ghirga ◽  
Deborah Quaglio ◽  
Maria Luisa Mangoni
Keyword(s):  
Antimicrobial Peptides ◽  
Biological Properties ◽  
Biological Profile ◽  
Innovative Strategy ◽  
Different Types ◽  
New Antibiotics ◽  
Interesting Class ◽  
Alternative Antimicrobials ◽  
Nanoparticulate Systems ◽  
Infective Activity

Cationic antimicrobial peptides (AMPs) are an interesting class of gene-encoded molecules endowed with a broad-spectrum of anti-infective activity and immunomodulatory properties. They represent promising candidates for the development of new antibiotics, mainly due to their membraneperturbing mechanism of action that very rarely induces microbial resistance. However, bringing AMPs into the clinical field is hampered by some intrinsic limitations, encompassing low peptide bioavailability at the target site and high peptide susceptibility to proteolytic degradation. In this regard, nanotechnologies represent an innovative strategy to circumvent these issues. According to the literature, a large variety of nanoparticulate systems have been employed for drug-delivery, bioimaging, biosensors or nanoantibiotics. The possibility of conjugating different types of molecules, including AMPs, to these systems, allows the production of nanoformulations able to enhance the biological profile of the compound while reducing its cytotoxicity and prolonging its residence time. In this minireview, inorganic gold nanoparticles (NPs) and biodegradable polymeric NPs made of poly(lactide-coglycolide) are described with particular emphasis on examples of the conjugation of AMPs to them, to highlight the great potential of such nanoformulations as alternative antimicrobials.

scholarly journals Anthocyanins Recovered from Agri-Food By-Products Using Innovative Processes: Trends, Challenges, and Perspectives for Their Application in Food Systems

Molecules ◽  
2021 ◽  
Vol 26 (9) ◽  
pp. 2632
Author(s):  
Henrique Silvano Arruda ◽  
Eric Keven Silva ◽  
Nayara Macêdo Peixoto Araujo ◽  
Gustavo Araujo Pereira ◽  
Glaucia Maria Pastore ◽  
...  
Keyword(s):  
Food Systems ◽  
Food Industry ◽  
Biological Properties ◽  
Extraction Techniques ◽  
Naturally Occurring ◽  
Current Review ◽  
Natural Colorants ◽  
Conventional Extraction ◽  
The Stability ◽  
By Products

Anthocyanins are naturally occurring phytochemicals that have attracted growing interest from consumers and the food industry due to their multiple biological properties and technological applications. Nevertheless, conventional extraction techniques based on thermal technologies can compromise both the recovery and stability of anthocyanins, reducing their global yield and/or limiting their application in food systems. The current review provides an overview of the main innovative processes (e.g., pulsed electric field, microwave, and ultrasound) used to recover anthocyanins from agri-food waste/by-products and the mechanisms involved in anthocyanin extraction and their impacts on the stability of these compounds. Moreover, trends and perspectives of anthocyanins’ applications in food systems, such as antioxidants, natural colorants, preservatives, and active and smart packaging components, are addressed. Challenges behind anthocyanin implementation in food systems are displayed and potential solutions to overcome these drawbacks are proposed.

scholarly journals Snail mucus from the mantle and foot of two land snails, Lissachatina fulica and Hemiplecta distincta, exhibits different protein profile and biological activity

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Nattaphop Noothuan ◽  
Kantamas Apitanyasai ◽  
Somsak Panha ◽  
Anchalee Tassanakajon
Keyword(s):  
Biological Activities ◽  
Protein Pattern ◽  
Protein Profile ◽  
Antibacterial Properties ◽  
Biological Properties ◽  
Specific Protein ◽  
Land Snails ◽  
Snail Species ◽  
Significant Difference ◽  
Different Types

Abstract Objective Snails secrete different types of mucus that serve several functions, and are increasingly being exploited for medical and cosmetic applications. In this study, we explored the protein pattern and compared the biological properties of the mucus secreted from the mantle collar and foot of two snail species, Lissachatina fulica and Hemiplecta distincta. Result Protein profile showed a different pattern between the two species and between the two secretory parts. The mantle-specific protein bands were further characterized and among them was an antibacterial protein, achacin. Accordingly, the mucus from the mantle exhibited the higher antibacterial activity than that from the foot in both snail species. The mucus from H. distincta, first reported here, also showed antibacterial properties, but with a lower activity compared to that for L. fulica. Snail mucus also exhibited anti-tyrosinase activity and antioxidant activity but with no significant difference between the foot and mantle mucus. These results indicate some different protein compositions and biological activities of snail slime from the mantle and foot, which might be associated with their specific functions in the animal and are useful for medical applications.

scholarly journals Cytotoxic Agents in the Minor Alkaloid Groups of the Amaryllidaceae

Planta Medica ◽  
2021 ◽  
Author(s):  
Jerald J. Nair ◽  
Johannes van Staden
Keyword(s):  
Cancer Cells ◽  
Cancer Cell Line ◽  
Structural Features ◽  
Biological Properties ◽  
Cytotoxic Agents ◽  
Plant Family ◽  
Structure Activity ◽  
Significant Interest ◽  
Different Types ◽  
Minor Alkaloid

AbstractOver 600 alkaloids have to date been identified in the plant family Amaryllidaceae. These have been arranged into as many as 15 different groups based on their characteristic structural features. The vast majority of studies on the biological properties of Amaryllidaceae alkaloids have probed their anticancer potential. While most efforts have focused on the major alkaloid groups, the volume and diversity afforded by the minor alkaloid groups have promoted their usefulness as targets for cancer cell line screening purposes. This survey is an in-depth review of such activities described for around 90 representatives from 10 minor alkaloid groups of the Amaryllidaceae. These have been evaluated against over 60 cell lines categorized into 18 different types of cancer. The montanine and cripowellin groups were identified as the most potent, with some in the latter demonstrating low nanomolar level antiproliferative activities. Despite their challenging molecular architectures, the minor alkaloid groups have allowed for facile adjustments to be made to their structures, thereby altering the size, geometry, and electronics of the targets available for structure-activity relationship studies. Nevertheless, it was seen with a regular frequency that the parent alkaloids were better cytotoxic agents than the corresponding semisynthetic derivatives. There has also been significant interest in how the minor alkaloid groups manifest their effects in cancer cells. Among the various targets and pathways in which they were seen to mediate, their ability to induce apoptosis in cancer cells is most appealing.

scholarly journals Delivery of cancer therapies by synthetic and bio-inspired nanovectors

2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Tina Briolay ◽  
Tacien Petithomme ◽  
Morgane Fouet ◽  
Nelly Nguyen-Pham ◽  
Christophe Blanquart ◽  
...  
Keyword(s):  
Recent Literature ◽  
Biological Properties ◽  
Engineered Nanoparticles ◽  
Oncolytic Viruses ◽  
Cancer Therapies ◽  
Different Types ◽  
Therapeutic Molecules ◽  
Tumor Specificity ◽  
Smart Drug ◽  
Smart Drug Delivery

Abstract Background As a complement to the clinical development of new anticancer molecules, innovations in therapeutic vectorization aim at solving issues related to tumor specificity and associated toxicities. Nanomedicine is a rapidly evolving field that offers various solutions to increase clinical efficacy and safety. Main Here are presented the recent advances for different types of nanovectors of chemical and biological nature, to identify the best suited for translational research projects. These nanovectors include different types of chemically engineered nanoparticles that now come in many different flavors of ‘smart’ drug delivery systems. Alternatives with enhanced biocompatibility and a better adaptability to new types of therapeutic molecules are the cell-derived extracellular vesicles and micro-organism-derived oncolytic viruses, virus-like particles and bacterial minicells. In the first part of the review, we describe their main physical, chemical and biological properties and their potential for personalized modifications. The second part focuses on presenting the recent literature on the use of the different families of nanovectors to deliver anticancer molecules for chemotherapy, radiotherapy, nucleic acid-based therapy, modulation of the tumor microenvironment and immunotherapy. Conclusion This review will help the readers to better appreciate the complexity of available nanovectors and to identify the most fitting “type” for efficient and specific delivery of diverse anticancer therapies.

scholarly journals Assessment of Titanate Nanolayers in Terms of Their Physicochemical and Biological Properties

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 806
Author(s):  
Michalina Ehlert ◽  
Aleksandra Radtke ◽  
Katarzyna Roszek ◽  
Tomasz Jędrzejewski ◽  
Piotr Piszczek
Keyword(s):  
Surface Modification ◽  
Substrate Surface ◽  
Biological Properties ◽  
Structure Characterization ◽  
Porous Coating ◽  
Apatite Formation ◽  
Sem Images ◽  
Energy Dispersion Spectroscopy ◽  
X Ray

The surface modification of titanium substrates and its alloys in order to improve their osseointegration properties is one of widely studied issues related to the design and production of modern orthopedic and dental implants. In this paper, we discuss the results concerning Ti6Al4V substrate surface modification by (a) alkaline treatment with a 7 M NaOH solution, and (b) production of a porous coating (anodic oxidation with the use of potential U = 5 V) and then treating its surface in the abovementioned alkaline solution. We compared the apatite-forming ability of unmodified and surface-modified titanium alloy in simulated body fluid (SBF) for 1–4 weeks. Analysis of the X-ray diffraction patterns of synthesized coatings allowed their structure characterization before and after immersing in SBF. The obtained nanolayers were studied using Raman spectroscopy, diffuse reflectance infrared Fourier transform spectroscopy (DRIFT), and scanning electron microscopy (SEM) images. Elemental analysis was carried out using X-ray energy dispersion spectroscopy (SEM EDX). Wettability and biointegration activity (on the basis of the degree of integration of MG-63 osteoblast-like cells, L929 fibroblasts, and adipose-derived mesenchymal stem cells cultured in vitro on the sample surface) were also evaluated. The obtained results proved that the surfaces of Ti6Al4V and Ti6Al4V covered by TiO2 nanoporous coatings, which were modified by titanate layers, promote apatite formation in the environment of body fluids and possess optimal biointegration properties for fibroblasts and osteoblasts.

Resistance to nitrofurantoin is an indicator of extensive drug-resistant (XDR) Enterobacteriaceae

2021 ◽  
Vol 70 (4) ◽  
Author(s):  
Balaram Khamari ◽  
Prakash Kumar ◽  
Bulagonda Eswarappa Pradeep
Keyword(s):  
Antimicrobial Agents ◽  
Efflux Pump ◽  
Treatment Options ◽  
Strong Association ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Content Type ◽  
Link Type

Introduction. Nitrofurantoin is one of the preferred antibiotics in the treatment of uropathogenic multidrug-resistant (MDR) infections. However, resistance to nitrofurantoin in extensively drug-resistant (XDR) bacteria has severely limited the treatment options. Gap statement. Information related to co-resistance or collateral sensitivity (CS) with reference to nitrofurantoin resistant bacteria is limited. Aim. To study the potential of nitrofurantoin resistance as an indicator of the XDR phenotype in Enterobacteriaceae . Methods. One hundred (45 nitrofurantoin-resistant, 21 intermediately resistant and 34 nitrofurantoin-susceptible) Enterobacteriaceae were analysed in this study. Antibiotic susceptibility testing (AST) against nitrofurantoin and 17 other antimicrobial agents across eight different classes was performed by using the Vitek 2.0 system. The isolates were screened for the prevalence of acquired antimicrobial resistance (AMR) and efflux pump genes by PCR. Results. In total, 51 % of nitrofurantoin-resistant and 28 % of intermediately nitrofurantoin resistant isolates exhibited XDR characteristics, while only 3 % of nitrofurantoin-sensitive isolates were XDR (P=0.0001). Significant co-resistance was observed between nitrofurantoin and other tested antibiotics (β-lactam, cephalosporin, carbapenem, aminoglycoside and tetracycline). Further, the prevalence of AMR and efflux pump genes was higher in the nitrofurantoin-resistant strains compared to the susceptible isolates. A strong association was observed between nitrofurantoin resistance and the presence of bla PER-1, bla NDM-1, bla OXA-48, ant(2) and oqxA-oqxB genes. Tigecycline (84 %) and colistin (95 %) were the only antibiotics to which the majority of the isolates were susceptible. Conclusion. Nitrofurantoin resistance could be an indicator of the XDR phenotype among Enterobacteriaceae , harbouring multiple AMR and efflux pump genes. Tigecycline and colistin are the only antibiotics that could be used in the treatment of such XDR infections. A deeper understanding of the co-resistance mechanisms in XDR pathogens and prescription of AST-based appropriate combination therapy may help mitigate this problem.

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