scholarly journals Polyhydroyalkanoates: from Basic Research and Molecular Biology to Application

2010 ◽  
Vol 9 (1) ◽  
pp. 37-73 ◽  
Author(s):  
Amro Abd alFattah Amara
Keyword(s):  
Inclusion Bodies ◽  
Basic Research ◽  
Biological Properties ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Limiting Factor ◽  
Bacterial Cells ◽  
Different Types ◽  
Insoluble Form ◽  
Soluble Components

This review describes the Polyhydroxyalkanoate (PHA), an intracellular biodegradable microbial polymer. PHAs is formed from different types of three hydroxyalkanoic acids monomers, each unit forms an ester bond with the hydroxyl group of the other one and the hydroxyl substituted carbon has R configuration. The C-3 atom in β position is branched with at least one carbon atom in the form of methyl group (C1) to thirteen carbons in the form of tridecyl (C13). This alkyl side chain is not necessarily saturated. PHAs are biosynthesized through regulated pathways by specific enzymes. PHAs are accumulated in bacterial cells from soluble to insoluble form as storage materials inside the inclusion bodies during unbalanced nutrition or to save organisms from reducing equivalents. PHAs are converted again to soluble components by PHAs depolymerases and the degraded materials enter various metabolic pathways. Until now, four classes of enzymes responsible for PHAs polymerization are known. PHAs were well studied regarding their promising applications, physical, chemical and biological properties. PHAs are biodegradable, biocompatible, have good material properties, renewable and can be used in many applications. The most limiting factor in PHAs commercialization is their high cost compared to the petroleum plastics. This review highlights the new knowledge and that established by the pioneers in this field as well as the factors, which affect PHAs commercialization.

scholarly journals PhaC Synthases and PHA Depolymerases: The Enzymes that Produce and Degrade Plastic

2011 ◽  
Vol 12 (4) ◽  
Author(s):  
Amro A. Amara ◽  
And Hassan Moawad
Keyword(s):  
Biodegradable Polymer ◽  
Inclusion Bodies ◽  
Degradation Process ◽  
Growth Conditions ◽  
Bacterial Cells ◽  
Unbalanced Growth ◽  
Storage Materials ◽  
Insoluble Form ◽  
Soluble Components

PHAs are a group of intracellular biodegradable polymer produced by (most) bacteria under unbalanced growth conditions. A series of enzymes are involved in different PHAs synthesis, however PhaC synthases are responsible for the polymerization step. PHAs are accumulated in bacterial cells from soluble to insoluble form as storage materials inside the inclusion bodies during unbalanced nutrition or to save organisms from reduces equivalents. PHAs are converted again to soluble components by another pathways and enzymes for the degradation process. PHAs depolymerases are the responsible enzymes. This review is designed to give the non-specialists a condense background about PHAs especially for researcher and students in medicinal and pharmaceutical filled. ABSTRAK: PHAs (polyhydroxyalkanoate) merupakan sekumpulan polimer terbiodegradasikan intrasel yang dihasilkan oleh (kebanyakan) bakteria di bawah keadaan tumbesaran tak seimbang. Satu rangkaian enzim terlibat dalam sistesis PHAs yang berbeza, namun sintesis PhaC bertanggungjawab dalam peringkat pempolimeran. PHAs dikumpulkan dalam sel bakteria dari bentuk larut dan tak larut sebagai bahan simpan di dalam jasad terangkum semasa nutrisi tak seimbang atau untuk menyelamatkan organisma daripada pengurangan tak keseimbangan. PHAs ditukarkan sekali lagi kepada komponen larut dengan cara lain dan enzim lain untuk proses degradasi. PHAs depoly-merases (enzim yang memangkin penguraian makro molekul kepada molekul yang lebih mudah) merupakan enzim yang bertanggunjawab. Kajian semula ini direka untuk memberi mereka yang bukan pakar, satu ringkasan tentang PHAs terutamanya penyelidik dan penuntut dalam bidang peubatan dan farmaseutikal.

scholarly journals The Prospect of Creating Medicines Based on Selenium Nanoparticles (Review)

2020 ◽  
Vol 9 (2) ◽  
pp. 33-44
Author(s):  
K. D. Skorinova ◽  
V. V. Kuzmenko ◽  
I. A. Vasilenko
Keyword(s):  
Cell Cultures ◽  
Cell Metabolism ◽  
Basic Research ◽  
Biological Properties ◽  
Scientific Data ◽  
Point Of View ◽  
Selenium Nanoparticles ◽  
New Drugs ◽  
Different Types ◽  
New Generation

Introduction. The prospects of using nanoparticles in the production of medicines are widely discussed in the literature. In 2018 alone, the quantity of registration certificates issued by national regulators for medicines that use nanoparticles in one form or another is around forty. Most of them are medicines based on liposomes, polymers, iron oxides, micelles. So far, no registration certificates have been issued for selenium nanoparticles. One of the reasons for this situation in this area, from our point of view, is that the mechanisms of interaction of nanoparticles with cells are not sufficiently studied. The lack of basic research in this area is one of the main obstacles to the development of new-generation drugs based on nanoparticles.Text. This review is devoted to the analysis of scientific data on the interaction of selenium nanoparticles with different types of cells. The article discusses the biological properties of selenium and its role in cell metabolism. Data on the cytotoxic effect of selenium nanoparticles on various cell cultures are presented. Methods of preparation of nanoparticles and methods for studying the interaction of nanoparticles with cell cultures are described.Conclusion. Analysis of the literature data allows us to draw conclusions about the relevance of research on the interaction of selenium nanoparticles with living cells. This is necessary to determine the mechanisms of selenium nanoparticles absorption, study their cytotoxic and / or cytostatic action, and distribution in cells. Investigation of the biological interaction of selenium nanoparticles with tumor and normal cells will determine the most informative methods for registering and quantifying their antitumor activity, which is relevant for the development of new drugs to treat cancer.

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.

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 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.

17α-HYDROXYLASE DEFICIENCY. A COMBINATION OF HYDROXYLATION DEFECT AND REVERSIBLE BLOCKADE IN ALDOSTERONE BIOSYNTHESIS

1979 ◽  
Vol 90 (3) ◽  
pp. 490-504 ◽  
Author(s):  
D. R. Rovner ◽  
J. W. Conn ◽  
E. L. Cohen ◽  
F. G. Berlinger ◽  
D. C. Kern ◽  
...  
Keyword(s):  
Plasma Concentration ◽  
Extracellular Fluid ◽  
Plasma Renin ◽  
Hydroxyl Group ◽  
Side Chain ◽  
Hydroxylase Deficiency ◽  
Resultant Increase

ABSTRACT We have studied the hormonal secretion and excretion patterns in a patient with the XX type of 17α-hydroxylase deficiency. In the untreated state, the patient's urine contained only those steroids which do not require 17-hydroxylation in their biosynthesis. Aldosterone was not produced in the patient and the metabolic product of its immediate precursor, 18-hydroxy-11-dehydro-tetrahydrocorticosterone, was excreted in markedly elevated amounts. This apparent complete block in 18 oxidation was reversible upon long-term ACTH suppression within 27 days. Direct in vitro incubation of the patient's adrenal gland removed at operation demonstrated, 1) the complete lack of 17α-hydroxylase activity, 2) the functional block in the ability to oxidize the hydroxyl group at the 18 methyl side chain. The addition of physiological concentrations of angiotensin to the incubation medium further showed, 3) angiotensin mildly stimulated the entire aldosterone biosynthetic pathway, 4) angiotensin directly stimulated the conversion of 18-hydroxycorticosterone to aldosterone. We propose that in this patient, 17-hydroxylase deficiency produced a decreased plasma concentration of cortisol, followed by stimulation of deoxycorticosterone production by ACTH. The resultant increase in extracellular fluid volume suppressed plasma renin activity. This resulted in a low plasma concentration of angiotensin II which directly suppressed oxidation of 18-hydroxycorticosterone to aldosterone. This defect has been called corticosterone methyl oxidase defect type 2.

scholarly journals Honey dressing on a leg ulcer with tendon exposure in a patient with type 2 diabetes

2018 ◽  
Vol 2018 ◽  
Author(s):  
Ilaria Teobaldi ◽  
Vincenzo Stoico ◽  
Fabrizia Perrone ◽  
Massimiliano Bruti ◽  
Enzo Bonora ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
Clinical Practice ◽  
Wound Dressing ◽  
Biological Properties ◽  
Healing Time ◽  
Foot Ulcers ◽  
Diabetic Foot Ulcers ◽  
Scientific Interest ◽  
Different Types

Summary Honey has been used as a wound dressing for hundreds of years by ancient civilizations, but only recently it has acquired scientific interest because of its relevant biological properties. In the last decade, indeed, several trials and observational studies have reported that, compared to conventional treatment (e.g. antiseptics, polyurethane film, paraffin gauze, soframycin-impregnated gauze), honey dressings seem to be better in healing time of different types of wounds, including diabetic foot ulcers. However, to date, information about a potential favorable biological effect of honey dressings on diabetic ulcers with exposed tendon are still scarce. Notably, foot or leg ulcers with exposed tendon are serious complications in patients with type 2 diabetes, as they are associated with an increased risk of adverse outcome. Therefore, the use of effective and safe treatments to bring these lesions to timely healing is very important in clinical practice. We herein report the case of a Caucasian adult patient with type 2 diabetes presenting a chronic right posterior lower limb ulcer (Texas University Classification (TUC) 2D) with tendon exposure that was successfully treated with honey dressings (glucose oxidase (GOX) positive with peroxide activity) in addition to systemic antibiotic therapy, surgical toilette and skin graft. In our case, the use of honey dressing for treating exposed tendon tissue probably allowed the timely wound healing. Although further studies are required, such treatment may constitute part of the comprehensive management of diabetic wounds, including those with tendon exposure, and should be considered by clinicians in clinical practice. Learning points: Honey has been used as a wound dressing for hundreds of years, but only recently it has acquired scientific interest for its biological properties. Several studies have documented that, compared to conventional dressings, honey seems to be better in healing time of different types of wounds, including diabetic foot ulcers. Our case report is the first to highlight the importance to use honey dressings also for the treatment of ulcers with tendon exposure in patients with type 2 diabetes, suggesting that this kind of dressing should be considered by clinicians in clinical practice.

scholarly journals Expression and Isolation of N-Terminal Truncated Human Recombinant Renalase in Prokaryotic Cells

2021 ◽  
Vol 4 (3) ◽  
pp. e00158
Author(s):  
V.I. Fedchenko ◽  
A.A. Kaloshin ◽  
S.A. Kaloshina ◽  
A.E. Medvedev
Keyword(s):  
Recombinant Protein ◽  
Signal Peptide ◽  
Extracellular Space ◽  
Inclusion Bodies ◽  
High Concentration ◽  
Genetic Construct ◽  
E Coli ◽  
Insoluble Form ◽  
Guanidine Chloride ◽  
Catalytic Functions

Renalase (RNLS) is a flavoproteinin which its N-terminal peptide (residues 1-17) has several important functions. In cells, it participates in the formation of the so-called Rossmanfold (residues 2-35), needed for «accommodation» of the FAD cofactor and for performing the catalytic functions of RNLS as a FAD-dependent oxidoreductase (EC 1.6.3.5). RNLS secretion into the extracellular space is accompanied by cleavage of this peptide. The resultant truncated extracellular RNLS cannot bind FAD and therefore performs various noncatalytic functions. In this work, we have performed expression the genetic construct encoding RNLS lacking its N-terminal signal peptide (tRNLS) in E. coli Rosetta (DE3) cells. The recombinant protein was accumulated in inclusion bodies in an insoluble form, which could be solubilized in the presence of a high concentration of urea or guanidine chloride. In contrast to full-length RNLS, which was effectively solubilized in the presence of 8 M urea, tRNLS was preferentially solubilized in the presence of 6 M guanidine chloride.

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