XBB.1.5 Kraken cracked: Gibbs energies of binding and biosynthesis of the XBB.1.5 variant of SARS-CoV-2

Structural and genomic evolutionary dynamics of Omicron variant of SARS-CoV-2 circulating in Madhya Pradesh, India

The SARS-CoV-2 Omicron (B.1.1.529) variant emerged in early November 2021 and its rapid spread created fear worldwide. This was attributed to its increased infectivity and escaping immune mechanisms. The spike protein of Omicron has more mutations (>30) than any other previous variants and was declared as the variant of concern (VOC) by the WHO. The concern among the scientific community was huge about this variant, and a piece of updated information on circulating viral strains is important in order to better understand the epidemiology, virus pathogenicity, transmission, therapeutic interventions, and vaccine development. A total of 710 samples were processed for sequencing and identification up to a resolution of sub-lineage. The sequence analysis revealed Omicron variant with distribution as follows: B.1.1, B.1.1.529, BA.1, BA.2, BA.2.10, BA.2.10.1, BA.2.23, BA.2.37, BA.2.38, BA.2.43, BA.2.74, BA.2.75, BA.2.76, and BA.4 sub-lineages. There is a shift noted in circulating lineage from BA.1 to BA.2 to BA.4 over a period from January to September 2022. Multiple signature mutations were identified in S protein T376A, D405N, and R408S mutations, which were new and common to all BA.2 variants. Additionally, R346T was seen in emerging BA.2.74 and BA.2.76 variants. The emerging BA.4 retained the common T376A, D405N, and R408S mutations of BA.2 along with a new mutation F486V. The samples sequenced were from different districts of Madhya Pradesh and showed a predominance of BA.2 and its variants circulating in this region. The current study identified circulation of BA.1 and BA.1.1 variants during initial phase. The predominant Delta strain of the second wave has been replaced by the Omicron variant in this region over a period of time. This study successfully deciphers the dynamics of the emergence and replacement of various sub-lineages of SARS-CoV-2 in central India on real real-time basis.

Has the human biological interaction with SARS-CoV2 variants entered a pliant "Faustian bargain"?

We hypothesize that a "Faustian bargain"-the trading of increased SARS-CoV2 viral infection with a concurrent potential for prevention of life-threatening lower lung infection explains the previous and future morbidity and mortality from COVID-19. Further, this trade-off is made feasible by fundamental principles of thermodynamics and receptor affinity.

Animal bioenergetics: Thermodynamic and kinetic analysis of growth and metabolism of Anguilla anguilla

Bioenergetics and biothermodynamics are valuable tools in research on growth and metabolic processes of a wide range of organisms, including viruses, bacteria, fungi, algae and plants, as is shown by the many publications on this topic in the literature. These studies provide insight into growth and metabolism of individual species, as well as interactions between species, like the virus-host interaction (infection) and virus-virus interaction (competition). However, this approach has not yet been applied to animal species. The universality of biothermodynamics and bioenergetics provides a good motive to apply them in analysis of animals. In this research, we made a bioenergetic, biothermodynamic and kinetic characterization for the first time for an animal species - Anguilla anguilla L. (European eel). We made a comparative analysis on yellow (young adult) and silver (mature adult) phases. Metabolic processes were modeled as chemical reactions with characteristic thermodynamic properties: enthalpy, entropy and Gibbs energy. Moreover, Gibbs energy explained growth rates, through phenomenological equations. This analysis of animal metabolism and growth explained metabolic properties of yellow and silver A. anguilla, including the bioenergetic aspect of life history. Moreover, we compared thermodynamic properties of A. anguilla with those of its main macromolecular components and other organisms. The thermodynamic properties were explained by the structural properties of organisms. This research extends the bioenergetic and biothermodynamic approaches to zoology, which should allow analysis of the energetic aspect of animal metabolic processes, interactions with their environment and interactions with other organisms. Furthermore, it connects the macroscopic perspective of zoology with the microscopic perspectives of biochemistry, bioenergetics and biothermodynamics. This will provide a basis for development of mechanistic models of animal growth and metabolism.

DNA-based assay for calorimetric determination of protein concentrations in pure or mixed solutions

It was recently reported that values of the transition heat capacities, as measured by differential scanning calorimetry, for two globular proteins and a short DNA hairpin in NaCl buffer are essentially equivalent, at equal concentrations (mg/mL). To validate the broad applicability of this phenomenon, additional evidence for this equivalence is presented that reveals it does not depend on DNA sequence, buffer salt, or transition temperature (Tm). Based on the equivalence of transition heat capacities, a calorimetric method was devised to determine protein concentrations in pure and complex solutions. The scheme uses direct comparisons between the thermodynamic stability of a short DNA hairpin standard of known concentration, and thermodynamic stability of protein solutions of unknown concentrations. Sequences of two DNA hairpins were designed to confer a near 20°C difference in their Tm values. In all cases, evaluated protein concentrations determined from the DNA standard curves agreed with the UV-Vis concentration for monomeric proteins. For multimeric proteins evaluated concentrations were greater than determined by UV-Vis suggesting the calorimetric approach can also be an indicator of molecular stoichiometry.

Clinical characteristics and novel mutations of omicron subvariant XBB in Tamil Nadu, India - a cohort study

BACKGROUND

Despite the continued vaccination efforts, there had been a surge in breakthrough infections, and the emergence of the B.1.1.529 omicron variant of SARS-CoV-2 in India. There is a paucity of information globally on the role of newer XBB variants in community transmission. Here, we investigated the mutational patterns among hospitalised patients infected with the XBB omicron sub-variant, and checked if there was any association between the rise in the number of COVID-19 cases and the observed novel mutations in Tamil Nadu, India.

METHODS

Nasopharyngeal and oropharyngeal swabs, collected from symptomatic and asymptomatic COVID-19 patients were subjected to real-time PCR followed by Next Generation Sequencing (NGS) to rule out the ambiguity of mutations in viruses isolated from the patients (n = 98). Using the phylogenetic association, the mutational patterns were used to corroborate clinico-demographic characteristics and disease severity among the patients.

FINDINGS

Overall, we identified 43 mutations in the S gene across 98 sequences, of which two were novel mutations (A27S and T747I) that have not been reported previously with XBB sub-variants in the available literature. Additionally, the XBB sequences from our cohort had more mutations than omicron B.1.1.529. The phylogenetic analysis comprising six major branches clearly showed convergent evolution of XBB. Our data suggests that age, and underlying conditions (e.g., diabetes, hypertension, and cardiovascular disease) or secondary complications confers increased susceptibility to infection rather than vaccination status or prior exposure. Many vaccinated individuals showed evidence of a breakthrough infection, with XBB.3 being the predominant variant identified in the study population.

INTERPRETATION

Our study indicates that the XBB variant is highly evasive from available vaccines and may be more transmissible, and potentially could emerge as the 'next' predominant variant, which likely could overwhelm the existing variants of SARS-CoV-2 omicron variants.

FUNDING

National Health Mission (India), SIDASARC, VINNMER (Sweden), ORIP/NIH (USA).

From genotype to phenotype with biothermodynamics: empirical formulas, biosynthesis reactions and thermodynamic properties of preproinsulin, proinsulin and insulin molecules

Insulin was discovered 100 years ago and has been well studied from the perspectives of life and biomedical sciences. This paper reports chemical and biothermodynamic properties of biosynthesis of insulin. This paper reports for the first time the molecular and empirical formulas, biosynthesis reactions, and thermodynamic properties of molecules and their biosynthesis for human preproinsulin, proinsulin, insulin chain A, insulin chain B, insulin, signal peptide and intermediate peptide (C-peptide). Based on these, metabolic reactions were formulated for conversion of preproinsulin to insulin and their thermodynamic feasibility was analyzed.Communicated by Ramaswamy H. Sarma.

Host Membranes as Drivers of Virus Evolution

The molecular mechanisms controlling the adaptation of viruses to host cells are generally poorly documented. An essential issue to resolve is whether host membranes, and especially lipid rafts, which are usually considered passive gateways for many enveloped viruses, also encode informational guidelines that could determine virus evolution. Due to their enrichment in gangliosides which confer an electronegative surface potential, lipid rafts impose a first control level favoring the selection of viruses with enhanced cationic areas, as illustrated by SARS-CoV-2 variants. Ganglioside clusters attract viral particles in a dynamic electrostatic funnel, the more cationic viruses of a viral population winning the race. However, electrostatic forces account for only a small part of the energy of raft-virus interaction, which depends mainly on the ability of viruses to form a network of hydrogen bonds with raft gangliosides. This fine tuning of virus-ganglioside interactions, which is essential to stabilize the virus on the host membrane, generates a second level of selection pressure driven by a typical induced-fit mechanism. Gangliosides play an active role in this process, wrapping around the virus spikes through a dynamic quicksand-like mechanism. Viruses are thus in an endless race for access to lipid rafts, and they are bound to evolve perpetually, combining speed (electrostatic potential) and precision (fine tuning of amino acids) under the selective pressure of the immune system. Deciphering the host membrane guidelines controlling virus evolution mechanisms may open new avenues for the design of innovative antivirals.

Development and Validation of a High-Performance Liquid Chromatography with Tandem Mass Spectrometry (HPLC-MS/MS) Method for Quantification of Major Molnupiravir Metabolite (β-D-N4-hydroxycytidine) in Human Plasma

Molnupiravir is an antiviral drug against viral RNA polymerase activity approved by the FDA for the treatment of COVID-19, which is metabolized to β-D-N4-hydroxycytidine (NHC) in human blood plasma. A novel method was developed and validated for quantifying NHC in human plasma within the analytical range of 10-10,000 ng/mL using high-performance liquid chromatography with tandem mass spectrometry (HPLC-MS/MS) to support pharmacokinetics studies. For sample preparation, the method of protein precipitation by acetonitrile was used, with promethazine as an internal standard. Chromatographic separation was carried out on a Shim-pack GWS C18 (150 mm × 4.6 mm, 5 μm) column in a gradient elution mode. A 0.1% formic acid solution in water with 0.08% ammonia solution (eluent A, v/v) and 0.1% formic acid solution in methanol with 0.08% ammonia solution mixed with acetonitrile in a 4:1 ratio (eluent B, v/v) were used as a mobile phase. Electrospray ionization (ESI) was used as an ionization source. The developed method was validated in accordance with the Eurasian Economic Union (EAEU) rules, based on the European Medicines Agency (EMA) and Food and Drug Administration (FDA) guidelines for the following parameters and used within the analytical part of the clinical study of molnupiravir drugs: selectivity, suitability of standard sample, matrix effect, calibration curve, accuracy, precision, recovery, lower limit of quantification (LLOQ), carryover, and stability.

SARS-CoV-2 strain wars continues: Chemical and thermodynamic characterization of live matter and biosynthesis of Omicron BN.1, CH.1.1 and XBC variants

SARS-CoV-2 has during the last 3 years mutated several dozen times. Most mutations in the newly formed variants have been chemically and thermodynamically characterized. New variants have been declared as variants under monitoring. The European Centre for Disease Prevention and Control has suggested the hypothesis that the new BN.1, CH.1.1 and XBC variants could have properties similar to those of VOC. Thermodynamic properties of new variants have been reported in this manuscript for the first time. Gibbs energy of biosynthesis, as the driving force for viral multiplication, is less negative for the new variants than for the earlier variants. This indicates that the virus has evolved towards decrease in pathogenicity, which leads to less severe forms of COVID-19.

Ghosts of the past: Elemental composition, biosynthesis reactions and thermodynamic properties of Zeta P.2, Eta B.1.525, Theta P.3, Kappa B.1.617.1, Iota B.1.526, Lambda C.37 and Mu B.1.621 variants of SARS-CoV-2

From the perspectives of molecular biology, genetics and biothermodynamics, SARS-CoV-2 is the among the best characterized viruses. Research on SARS-CoV-2 has shed a new light onto driving forces and molecular mechanisms of viral evolution. This paper reports results on empirical formulas, biosynthesis reactions and thermodynamic properties of biosynthesis (multiplication) for the Zeta P.2, Eta B.1.525, Theta P.3, Kappa B.1.617.1, Iota B.1.526, Lambda C.37 and Mu B.1.621 variants of SARS-CoV-2. Thermodynamic analysis has shown that the physical driving forces for evolution of SARS-CoV-2 are Gibbs energy of biosynthesis and Gibbs energy of binding. The driving forces have led SARS-CoV-2 through the evolution process from the original Hu-1 to the newest variants in accordance with the expectations of the evolution theory.

Molecular In-Depth on the Epidemiological Expansion of SARS-CoV-2 XBB.1.5

Since the beginning of the pandemic, the generation of new variants periodically recurs. The XBB.1.5 SARS-CoV-2 variant is one of the most recent. This research was aimed at verifying the potential hazard of this new subvariant. To achieve this objective, we performed a genome-based integrative approach, integrating results from genetic variability/phylodynamics with structural and immunoinformatic analyses to obtain as comprehensive a viewpoint as possible. The Bayesian Skyline Plot (BSP) shows that the viral population size reached the plateau phase on 24 November 2022, and the number of lineages peaked at the same time. The evolutionary rate is relatively low, amounting to 6.9 × 10−4 subs/sites/years. The NTD domain is identical for XBB.1 and XBB.1.5 whereas their RBDs only differ for the mutations at position 486, where the Phe (in the original Wuhan) is replaced by a Ser in XBB and XBB.1, and by a Pro in XBB.1.5. The variant XBB.1.5 seems to spread more slowly than sub-variants that have caused concerns in 2022. The multidisciplinary molecular in-depth analyses on XBB.1.5 performed here does not provide evidence for a particularly high risk of viral expansion. Results indicate that XBB.1.5 does not possess features to become a new, global, public health threat. As of now, in its current molecular make-up, XBB.1.5 does not represent the most dangerous variant.