Tensegrity applied to modelling the motion of viruses

A considerable number of viruses’structures have been discovered and more are expected to be identified.Different viruses’symmetries can be observed at the nanoscale level.The mechanical models of some viruses realised by scientists are described in this paper,none of which has taken into consideration the internal deformation of subsystems. The authors’models for some viruses’elements are introduced,with rigid and flexible links,which reproduce the movements of viruses including internal deformations of the subunits.     

Chromatography of proteins and viruses on macroporous silica modified with carbohydrates

Summary The adsorption and the chromatography of proteins and viruses on macroporoussilicas have been studied. Modification of the silica surfaces with -aminopropyltriethoxysilane and then with carbohydrates has eliminated the irreversible adsorption of these biopolymers. The chromatographic separation of the biopolymers has revealed molecular sieve (size exclusion) effects and reversible adsorption. The influence of pH on the elution of proteins and viruses has been demonstrated.     

Interferons

Interferons are proteins which bring about a nonspecific and nonimmunological defence reaction against virus infections in vertebrates. Interferon formation is induced in vivo and in vitro by viruses and other agents, e.g. endotoxins, nucleic acids, synthetic anionic copolymers, and phytohemagglutinins. All attempts to produce pure interferons have so far been unsuccessful. Interferons can only exert an antiviral action when the cellular RNA and protein synthesis is intact.     

Architecture of small RNA viruses

Symmetric organization of biological macromolecules is necessary for certain structural and functional requirements of living cells. The mechanisms by which biomolecules assemble unambiguously into unique structures has been a central theme of investigation in molecular biology. Simple viruses consist of a nucleic acid core which codes for the genetic information surrounded and protected by a protein coat or capsid. In a large majority of the cases, the protein coats possess exact icosahedral symmetry. Developments in experimental X-ray crystallography and computer technology has led recently to the elucidation of the architecture of several viruses. Systematic studies on the structure of the protein subunits, their location and orientation on the icosahedral capsid, and the details of interaction between subunits has provided some insights into the mechanisms of error free virus assembly. However, the structures of even the simplest viruses are sufficiently complex and do not lead to complete understanding of the pathway of assembly by an examination of the final structure. The current state of research in this fast advancing area is briefly reviewed.     

Application of molecularly imprinted polymers for electrochemical detection of some important biomedical markers and pathogens

The determination of biomedical markers and pathogens using electrochemical sensors is a well-established technique in which the transducer and the recognition element are used to detect the target molecule. There is a growing interest in molecularly imprinted polymer (MIPs) applications as promising recognition elements. The use of MIPs as recognition elements in electrochemical sensors offers the advantages of being fast, low cost, and, at the same time, provides accurate and selective results compared with other commonly applied routine methods for biomedical markers and pathogen detection. Compared with other nanomaterials and aptamer-based biosensors, MIP-based sensors offered excellent selectivity for low-priced reagents to be used. The aim of the current review is to discuss the most recent applications of MIP-based electrochemical sensors (2019–2021) as promising detection devices for some important biomarkers, enzymes, and pathogens, such as viruses, bacteria, and toxins.     

Chemotherapy of virus diseases.

The purpose of this review is to provide an overview of current screening methodology and major advances in the area of viral chemotherapy. This presentation will be limited to those drugs which are currently in use and those which having shown activity against major human pathogenic viruses are now being evaluated in man.     

Study on the interaction between hepatitis B virus functional receptor NTCP and ligands by surface plasmon resonanceEI北大核心CSCD

Sodium/taurocholate cotransporting polypeptideNTCPSLC10A1mediates the entry of hepatitis B virusHBVinto hepatocytes. NTCP is the functional receptor for HBV infection and a potential target for anti-HBV drugs. At presentmethods that evaluate the interaction between NTCP and its ligands are still limited. In this paperthe recombinant NTCP was expressed by Sf9 cells and purifiedand fixed on the surface plasmon resonanceSPRsensor chip by indirect antibody coupling. According to SPR kinetic analysisthe equilibrium dissociation constant KD of HBV PreS1 polypeptide binding to NTCP is 4.93 μµmol/L. The equilibrium dissociation constant KD of classic substrate taurocholate sodium for NTCP is 25.3 μµmol/L. Rather than the inhibition capacity of compounds to block NTCP substrate transportationthe equilibrium dissociation constant measured by SPR method can compare the binding affinity of compounds to NTCPand can be used to develop anti-HBV drugs based on NTCP-PreS1 interaction. © 2022, Youke Publishing Co.,Ltd. All rights reserved.     

Detecting conserved secondary structures in RNA molecules using constrained structural alignment

Constrained sequence alignment has been studied extensively in the past. Different forms of constraints have been investigated, where a constraint can be a subsequence, a regular expression, or a probability matrix of symbols and positions. However, constrained structural alignment has been investigated to a much lesser extent. In this paper, we present an efficient method for constrained structural alignment and apply the method to detecting conserved secondary structures, or structural motifs, in a set of RNA molecules. The proposed method combines both sequence and structural information of RNAs to find an optimal local alignment between two RNA secondary structures, one of which is a query and the other is a subject structure in the given set. The method allows a biologist to annotate conserved regions, or constraints, in the query RNA structure and incorporates these regions into the alignment process to obtain biologically more meaningful alignment scores. A statistical measure is developed to assess the significance of the scores. Experimental results based on detecting internal ribosome entry sites in the RNA molecules of hepatitis C virus and Trypanosoma brucei demonstrate the effectiveness of the proposed method and its superiority over existing techniques.     

Methods of virus formation

Viruses occur in a great variety of shapes and sizes, but for all their diversity in appearance they possess certain characteristics in common: all viruses contain a single nucleic acid molecule – deoxyribonucleic acid (DNA) or ribonucleic acid (RNA) – surrounded by a protective protein coat. Among other things, the protein coat enables the genetic information stored in the nucleic acid to enter a host cell in a usable state, where it can initiate the reproduction of identical virus particles. After penetration of the cell the foreign genetic material of the virus particle first induces the synthesis of macromolecules not normally present in the cell: the viral nucleic acid undergoes replication and very many copies are produced, the protein of the virus coat is synthesized, and then these components are assembled to form a new generation of infectious virus particles. Most viruses also exhibit certain common structural features: their protein coat is built up from subunits arranged in helical or icosahedral fashion around the genetic material.     

Viruses More Friends than Foes

Viruses are normally defined as pathogens and have a bad reputation because of pandemics such as Influenza, HIV/AIDS, Ebola, and SARS. Most viruses are, however, not enemies or killers but play important roles in the origin, development and maintenance of life of all species on our planet. This is new information we learnt by new technologies such as sequencing. Viruses are the most successful species on Earth, they are ubiquitous, in the oceans, in our environment, in animals, plants, bacteria, up in the air, perhaps even in the universe, within our body and even as part of our genomes. They influence our health, our well‐being, mental properties, our gut microbiota including obesity, and may help to cope with multi‐drug‐resistant bacteria. There the phages, viruses of bacteria, raise hopes. Viruses built our immunity: viruses protect against viruses. We do not have to lay eggs – thanks to viruses! They are the drivers of evolution and adaptation to environmental changes, also e. g. in plankton. The success story of viruses started about 3.5 billion years ago when life began. Newly discovered giant viruses are almost bacteria in their composition, suggesting that the borderline between dead matter and life is continuous. There are many open questions – how did life begin, is there life on exoplanets, how to find it? Are virus‐like elements, viroids, important for the origin of life? Will viruses eliminate mankind [1]?