Physiological Conditions Research Articles

A laser-Engraved Wearable Electrochemical Sensing Patch for Heat Stress Precise Individual Management of Horse.

In point-of-care diagnostics, the continuous monitoring of sweat constituents provides a window into individual's physiological state. For species like horses, with abundant sweat glands, sweat composition can serve as an early health indicator. Considering the salience of such metrics in the domain of high-value animal breeding, a sophisticated wearable sensor patch tailored is introduced for the dynamic assessment of equine sweat, offering insights into pH, potassium ion (K+), and temperature profiles during episodes of heat stress and under normal physiological conditions. The device integrates a laser-engraved graphene (LEG)sensing electrode array, a non-invasive iontophoretic module for stimulated sweat secretion, an adaptable signal processing unit, and an embedded wireless communication framework. Profiting from an admirable Truth Table capable of logical evaluation, the integrated system enabled the early and timely assessment for heat stress, with high accuracy, stability, and reproducibility. The sensor patch has been calibrated to align with the unique dermal and physiological contours of equine anatomy, thereby augmenting its applicability in practical settings. This real-time analysis tool for equine perspiration stands to revolutionize personalized health management approaches for high-value animals, marking a significant stride in the integration of smart technologies within the agricultural sector.

Status of visfatin in female reproductive function under normal and pathological conditions: a mini review.

Adipokines are now well-known to regulate reproduction. Visfatin is an adipokine expressed in the hypothalamus, pituitary, ovary, uterus, and placenta of different species, and since it has been found to modulate the endocrine secretion of the hypothalamus, pituitary gland and ovary, it may be considered a novel regulator of female reproduction. Although the majority of the literature explored its role in ovarian regulation, visfatin has also been shown to regulate uterine remodeling, endometrial receptivity and embryo development, and its expression in the uterus is steroid dependent. Like other adipokines, visfatin expression and levels are deregulated in pathological conditions including polycystic ovary syndrome. Thus, the present mini-review focuses on the role of visfatin in female reproduction under both physiological and pathological conditions.

The impact of normothermic and hypothermic preservation methods on kidney lipidome-comparative study using chemical biopsy with microextraction probes.

Normothermic ex vivo kidney perfusion (NEVKP) is designed to replicate physiological conditions to improve graft outcomes. A comparison of the impact of hypothermic and normothermic preservation techniques on graft quality was performed by lipidomic profiling using solid-phase microextraction (SPME) chemical biopsy as a minimally invasive sampling approach. Direct kidney sampling was conducted using SPME probes coated with a mixed-mode extraction phase in a porcine autotransplantation model of the renal donor after cardiac death, comparing three preservation methods: static cold storage (SCS), NEVKP, and hypothermic machine perfusion (HMP). The lipidomic analysis was done using ultra-high-performance liquid chromatography coupled with a Q-Exactive Focus Orbitrap mass spectrometer. Chemometric analysis showed that the NEVLP group was separated from SCS and HMP groups. Further in-depth analyses indicated significantly (p < 0.05, VIP > 1) higher levels of acylcarnitines, phosphocholines, ether-linked and longer-chain phosphoethanolamines, triacylglycerols and most lysophosphocholines and lysophosphoethanolamines in the hypothermic preservation group. The results showed that the preservation temperature has a more significant impact on the lipidomic profile of the kidney than the preservation method's mechanical characteristics. Higher levels of lipids detected in the hypothermic preservation group may be related to ischemia-reperfusion injury, mitochondrial dysfunction, pro-inflammatory effect, and oxidative stress. Obtained results suggest the NEVKP method's beneficial effect on graft function and confirm that SPME chemical biopsy enables low-invasive and repeated sampling of the same tissue, allowing tracking alterations in the graft throughout the entire transplantation procedure.

Efferocytosis by macrophages in physiological and pathological conditions: regulatory pathways and molecular mechanisms.

Efferocytosis is defined as the highly effective phagocytic removal of apoptotic cells (ACs) by professional or non-professional phagocytes. Tissue-resident professional phagocytes ("efferocytes"), such as macrophages, have high phagocytic capacity and are crucial to resolve inflammation and aid in homeostasis. Recently, numerous exciting discoveries have revealed divergent (and even diametrically opposite) findings regarding metabolic immune reprogramming associated with efferocytosis by macrophages. In this review, we highlight the key metabolites involved in the three phases of efferocytosis and immune reprogramming of macrophages under physiological and pathological conditions. The next decade is expected to yield further breakthroughs in the regulatory pathways and molecular mechanisms connecting immunological outcomes to metabolic cues as well as avenues for "personalized" therapeutic intervention.

Lipid mediators in neutrophil biology: inflammation, resolution and beyond.

Acute inflammation is the body's first defense in response to pathogens or injury. Failure to efficiently resolve the inflammatory insult can severely affect tissue homeostasis, leading to chronic inflammation. Neutrophils play a pivotal role in eradicating infectious pathogens, orchestrating the initiation and resolution of acute inflammation, and maintaining physiological functions. The resolution of inflammation is a highly orchestrated biochemical process, partially modulated by a novel class of endogenous lipid mediators known as specialized pro-resolving mediators (SPMs). SPMs mediate their potent bioactions via activating specific cell-surface G protein-coupled receptors (GPCR). This review focuses on recent advances in understanding the multifaceted functions of SPMs, detailing their roles in expediting neutrophil apoptosis, promoting clearance by macrophages, regulating their excessive infiltration at inflammation sites, orchestrating bone marrow deployment, also enhances neutrophil phagocytosis and tissue repair mechanisms under both physiological and pathological conditions. We also focus on the novel role of SPMs in regulating bone marrow neutrophil functions, differentiation, and highlight open questions about SPMs' functions in neutrophil heterogeneity. SPMs play a pivotal role in mitigating excessive neutrophil infiltration and hyperactivity within pathological milieus, notably in conditions such as sepsis, cardiovascular disease, ischemic events, and cancer. This significant function highlights SPMs as promising therapeutic agents in the management of both acute and chronic inflammatory disorders.

A cell based assay using virus-like particles to screen AM type mimics for SARS-CoV-2 neutralisation

A number of small molecule and protein therapeutic candidates have been developed in the last four years against SARS-CoV-2 spike. However, there are hardly a few molecules that have advanced through the subsequent discovery steps to eventually work as a therapeutic agent. This is majorly because of the hurdles in determining the affinity of potential therapeutics with live SARS-CoV-2 virus. Furthermore, affinity determined for the receptor binding domain (RBD) of the SARS-CoV-2 spike protein, at times, fails to mimic physiological conditions of the host-virus interaction. To bridge this gap between in vitro and in vivo methods of therapeutic agent screening, we report an improved screening protocol for therapeutic candidates using SARS-CoV-2 virus like particles (VLPs). To minimise the interference from the bulkier reporters like GPF in the affinity studies, a smaller hemagglutinin (HA) tag has been fused to one of the proteins of VLP. This HA tag serves as readout, when probed with fluorescent anti-HA antibodies. Outcome of this study sheds light on the lesser known virus neutralisation capabilities of AM type miniprotein mimics. Further, to assess the stability of SARS-CoV-2 spike - miniprotein complex, we have performed molecular dynamic simulations on the membrane embedded protein complex. Simulation results reveal extremely stable intermolecular interactions between RBD and one of the AM type miniproteins, AM1. Furthermore, we discovered a robust network of intramolecular interactions that help stabilise AM1. Findings from our in vitro and in silico experiments concurrently highlight advantages and capabilities of mimic based miniprotein therapeutics.

A knowledge-driven graph convolutional network for abnormal electrocardiogram diagnosis

The electrocardiogram (ECG) signal comprising P-, Q-, R-, S-, and T-waves is an indispensable noninvasive diagnostic tool for analyzing physiological conditions of the heart. In general, traditional ECG intelligent diagnosis methods gradually extract features of the signal from input data until they can classify the ECG signal. However, the decision-making process of ECG intelligence models is implicit to clinicians. Clinical experts rely on clear and specific features extracted from ECG data to diagnose cardiac diseases effectively. Inspired by this clinical diagnosis mechanism, we propose an ECG knowledge graph (ECG-KG) framework primarily to improve ECG classification by presenting knowledge of ECG clinical diagnosis. In particular, the ECG-KG framework contains an ECG semantic feature extraction module, a knowledge graph construction module, and an ECG classification module. First, the ECG semantic feature extraction module locates the key points using the difference value method and further calculates the ECG attribute features. Further, the knowledge graph construction module utilizes attribute features to design entities and relationships for constructing abnormal ECG triples. The triples vectorize ECG abnormalities through the strategy of knowledge graph embedding strategy. Finally, the ECG classification module combines the ECG knowledge graph with the graph convolutional network model and adequately integrates expert knowledge to identify ECG abnormalities. Experiments conducted on the benchmark QT, the CPSC-2018, and the ZZU-ECG datasets show that the ECG-KG framework considerably outperforms other ECG diagnosis models, indicating the effectiveness of the ECG-KG framework for ECG abnormality diagnosis.

The IMPDH cytoophidium couples metabolism and fetal development in mice

The cytoophidium is an evolutionarily conserved subcellular structure formed by filamentous polymers of metabolic enzymes. In vertebrates, inosine monophosphate dehydrogenase (IMPDH), which catalyses the rate-limiting step in guanosine triphosphate (GTP) biosynthesis, is one of the best-known cytoophidium-forming enzymes. Formation of the cytoophidium has been proposed to alleviate the inhibition of IMPDH, thereby facilitating GTP production to support the rapid proliferation of certain cell types such as lymphocytes, cancer cells and pluripotent stem cells (PSCs). However, past studies lacked appropriate models to elucidate the significance of IMPDH cytoophidium under normal physiological conditions. In this study, we demonstrate that the presence of IMPDH cytoophidium in mouse PSCs correlates with their metabolic status rather than pluripotency. By introducing IMPDH2 Y12C point mutation through genome editing, we established mouse embryonic stem cell (ESC) lines incapable of forming IMPDH polymers and the cytoophidium. Our data indicate an important role of IMPDH cytoophidium in sustaining a positive feedback loop that couples nucleotide biosynthesis with upstream metabolic pathways. Additionally, we find that IMPDH2 Y12C mutation leads to decreased cell proliferation and increased DNA damage in teratomas, as well as impaired embryo development following blastocoel injection. Further analysis shows that IMPDH cytoophidium assembly in mouse embryonic development begins after implantation and gradually increases throughout fetal development. These findings provide insights into the regulation of IMPDH polymerisation in embryogenesis and its significance in coordinating cell metabolism and development.

Exploring enzyme inhibition and comprehensive mechanisms of antioxidant/prooxidative activity of natural furanocoumarin derivatives: A comparative kinetic DFT study

This study aimed to explore the antioxidant and prooxidative activity of two natural furanocoumarin derivatives, Bergaptol (4-Hydroxy-7H-furo [3,2-g] [1]benzopyran-7-one, BER) and Xanthotoxol (9-Hydroxy-7H-furo [3,2-g] [1]benzopyran-7-one, XAN). The collected thermodynamic and kinetic data demonstrate that both compounds possess substantial antiradical activity against HO• and CCl3OO• radicals in physiological conditions. BER exhibited better antiradical activity in comparison to XAN, which can be attributed to the enhanced deprotonation caused by the positioning of the –OH group on the psoralen ring. In contrast to highly reactive radical species, newly formed radical species BER• and XAN• exhibited negligible reactivity towards the chosen constitutive elements of macromolecules (fatty acids, amino acids, nucleobases). Furthermore, in the presence of O2•─, the ability to regenerate newly formed radicals BER• and XAN• was observed. Conversely, in physiological conditions in the presence of Cu(II) ions, both compounds exhibit prooxidative activity. Nevertheless, the prooxidative activity of both compounds is less prominent than their antioxidant activity. Furthermore, it has been demonstrated that anionic species can engage in the creation of a chelate complex, which restricts the reduction of metal ions when reducing agents are present (O2•─ and Asc─). Moreover, studies have demonstrated that these chelating complexes can be coupled with other radical species, hence enhancing their ability to inactivate radicals. Both compounds exhibited substantial inhibitory effects against enzymes involved in the direct or indirect generation of ROS: Xanthine Oxidase (XOD), Lipoxygenase (LOX), Myeloperoxidase (MPO), NADPH oxidase (NOX).

Molecular approaches to deploy singlet oxygen in a Leishmania model as an unassailable biocide for disease mitigation and vector control

Singlet oxygen (1O2) is a potent biocide potentially deployable for integrated control of tropical diseases and their insect vectors. This very short-lived free radical is highly destructive of cellular molecules when generated intracellularly. Most organisms, including parasites and vectors, are defenseless against 1O2 except for plants, which produce it abundantly during photosynthesis, hence, the acquisition of specific mechanisms for its detoxification. In the presence of O2 under physiological conditions, certain dyes or photosensitizers (PS), e.g., porphyrins and phthalocyanines (PC), are excitable by light to produce biocidal 1O2. Its half-life is in the order of microseconds, necessitating its intracellular generation in order to harness its biocidal activity most effectively. This is achievable by loading cells with PS for excitation with light to produce 1O2in situ. One example to achieve this is the genetic engineering of Leishmania to complement its inherent defects in porphyrin biosynthesis, resulting in cytosolic accumulation of abundant PS in the form of uroporphyrin 1 (URO). Another example is the chemical engineering of PC for hydrophilicity, thereby facilitating the endocytosis of such PS by cells. Leishmania loaded with cytosolic URO and endosomal PC are inactivated by the 1O2 produced via light-activation of these PS in the two different cell compartments. The inactivated Leishmania are nonviable, but have their natural vaccines and adjuvants well-preserved for prophylactic vaccination against experimental leishmaniasis. 1O2-inactivated Leishmania is potentially useful to serve as a platform for the safe and effective delivery of transgenically add-on vaccines against malignant and viral diseases in experimental models. Hydrophilic and cationic PC were also shown experimentally to act as a new type of dim light-activable insecticides, i.e., their mosquito larvicidal activities with &amp;lt;µM LD50 values. Similar results are expected by studying PC in additional laboratory insect models. A significant advantage has long been attributed to this type of insecticide, i.e., their aversion to a selection of genetic variants for resistance. An additional advantage of PC is their excitability to produce insecticidal 1O2 with deep-penetrating red or infrared light invisible to most insects, thereby potentially increasing the range and scope of targetable insect vectors.

Development of a Selective and Stable Antimicrobial Peptide.

Antimicrobial peptides (AMPs) are presented as potential scaffolds for antibiotic development due to their desirable qualities including broad-spectrum activity, rapid action, and general lack of susceptibility to current resistance mechanisms. However, they often lose antibacterial activity under physiological conditions and/or display mammalian cell toxicity, which limits their potential use. Identification of AMPs that overcome these barriers will help develop rules for how this antibacterial class can be developed to treat infection. Here we describe the development of our novel synthetic AMP, from discovery through in vivo application. Our evolved AMP, DTr18-dab, has broad-spectrum antibacterial activity and is nonhemolytic. It is active against planktonic bacteria and biofilm, is unaffected by colistin resistance, and importantly is active in both human serum and a Galleria mellonella infection model. Several modifications, including the incorporation of noncanonical amino acids, were used to arrive at this robust sequence. We observed that the impact on antibacterial activity with noncanonical amino acids was dependent on assay conditions and therefore not entirely predictable. Overall, our results demonstrate how a relatively weak lead can be developed into a robust AMP with qualities important for potential therapeutic translation.

Application of hyperbranched polysiloxanes in biomedical materials based on AIE polymer properties

Application of hyperbranched polysiloxanes in biomedical materials based on AIE polymer properties

Spermatogenesis in cultured blue mussel (Mytilus edulis) from a cold‐ocean environment: Seasonal spatiotemporal expression of three gamete‐associated molecular markers

AbstractTo understand the seasonality of spermatogenesis in cultured males of Mytilus edulis from a cold‐ocean environment, we investigated the cellular transitions occurring within the spermatogenic epithelium of the testicular acini during early and advancing spermatogenesis, with specific reference to the histology of the epithelium, gene specific spermatogenic response, condition, culture environment, and season. A combination of histological evaluation, qPCR analysis, and in situ hybridization was used to examine the cellular transitions taking place in the germinal epithelium from late winter through to a seasonal spawn in summer. We observed clear seasonal transitionary changes in the spermatogenic cell population making up the germinal epithelium (i.e., spermatogonial stem cells, spermatocytes, spermatids, and spermatozoa) extending from February to July. These seasonal transitions in spermatogenic cell type coincided with significant variation in the spatiotemporal expression of two molecular markers for spermatogenesis (i.e., Kelch‐like protein 10 [KLHL10] and Armadillo repeat‐containing protein 4 isoform X2 [ARMC4]) but not for expression of a gamete‐specific Mitochondrial cytochrome oxidase I (MT‐COI). The spatiotemporal expression of these genes is directly linked to the cellular changes taking place in the germinal epithelium during spermatogenesis. These observations not only corresponded to seasonal changes in physiological condition but also environmental temperature and chlorophyll a, thus further supporting the link between male gametogenesis and environment in higher latitude regions.

A selective fluorescent probe derived from benzo[d]imidazole for carbon dioxide detection and bioimaging

In this work, a benzo[d]imidazole-derived fluorescent probe, DCBIF, was developed for the carbon dioxide (CO2) detection and imaging in living lung cells. On the basis of investigating previous reports and modifying the test method, the in-solution experiments showed that DCBIF exhibited the fluorescence response at 420 nm to CO2 under the excitation of 350 nm. The response was steady and rapid in physiological conditions. The linear range of the detecting system covered the practical necessity, and the limit of detection was 0.002 mL/min. There were few reports for detecting CO2 depicted the intracellular imaging while the cells were not pulmonary. Herein, in all the tested groups including oxygen-rich, hypoxia, and hypoxia recovered, DCBIF realized the imaging of the CO2 level in living A549 lung cells. This work was meaningful for developing fluorescent implements and imaging scenarios.

Formulating biomolecular crowns on micelles: A potential strategy for improving micelle stability

The complex environment in blood circulation has a tremendous destabilizing effect on the micelles structure, which is a vital issue to be addressed in micelles design and application. Biomolecule crowns, quickly formed on the surface of nanocarriers in vivo, may alter the physicochemical properties of nanocarriers. In this study, bovine serum albumin (BSA) or fetal bovine serum (FBS) was formulated as the biomolecular crown of the bacterial lipase-responsive micelles encapsulating the hydrophobic antibiotics chloramphenicol (CHL) to investigate their stabilization effect on the micelles. Compared with BSA-crowned micelles (BSA/PM@CHL), FBS-crowned micelles (FBS/PM@CHL) reduced drug leakage by more than 90 % without masking their lipase responsiveness, it also inhibited 77 % of bacterial growth in in vitro antibacterial activity study and significantly increased the area under plasma concentration curve and in vivo half-life in pharmacokinetic study. Then the Förster resonance energy transfer (Fret) Effect was used to further explore the mechanisms responsible for the differences between the BSA-crown and FBS-crown. The in vitro anti-dilution tests below the critical micellar concentration showed that FBS-crown could improve the thermodynamic stability of the micelles, the micelle integrity of FBS/PM was 2 times higher than that of PM diluted with aqueous dilution and 6.5 times higher than that diluted with rat plasma dilution. In vivo optical imaging study showed that micelles with dual-labeled FBS/PM (mean value = 0.363) maintained better structural integrity than dual-labeled PM (mean value = 0.325) after 4 h of injection, explaining the ability of FBS-crowned micelles to improve pharmacokinetic parameters in terms of thermodynamic stability. Besides, the destruction of PM integrity slowed down after injection into the blood circulation for 4–8h, indicating that the baring of biomolecular-crown may be in the late cycle. Overall, the biomolecular-crowned micelles strategy presents a promising strategy for maintaining the structural and functional stability of micelles under physiological conditions.

Nuclear Magnetic Resonance (NMR) Metabolomics: Current Applications in Equine Health Assessment.

Metabolomics can allow for the comprehensive identification of metabolites within biological systems, at given time points, in physiological and pathological conditions. In the last few years, metabolomic analysis has gained popularity both in human and in veterinary medicine, showing great potential for novel applications in clinical activity. The aim of applying metabolomics in clinical practice is understanding the mechanisms underlying pathological conditions and the influence of certain stimuli (i.e., drugs, nutrition, exercise) on body systems, in the attempt of identifying biomarkers that can help in the diagnosis of diseases. Proton Nuclear Magnetic Resonance spectroscopy (1H-NMR) is well tailored to be used as an analytical platform for metabolites' detection at the base of metabolomics studies, due to minimal sample preparation and high reproducibility. In this mini-review article, the scientific production of NMR metabolomic applications to equine medicine is examined. The research works are very different in methodology and difficult to compare. Studies are mainly focused on exercise, reproduction, and nutrition, other than respiratory and musculoskeletal diseases. The available information on this topic is still scant, but a greater collection of data could allow researchers to define new reliable markers to be used in clinical practice for diagnostic and therapeutical purposes.

Incidence and Factors Associated with Falls in Older People in a Long-Term Care Facility: A Prospective Study in Taiwan.

The effectiveness of applying a fall-risk assessment to prevent falls in residents of long-term care facilities has not been investigated. This prospective study enrolled elderly residents in a long-term care facility in Taiwan. Caregivers were provided with a health-status assessment and fall-risk data to enhance their fall-prevention practices. A multivariate analysis was performed to identify the factors associated with falls. A total of 123 subjects, including 68 and 55 for general and nursing-care models, respectively, were assessed. Their health status and risk of falls were provided to the care units to enhance their fall-prevention practices. Subjects in the nursing-care model had more dementia and more prescribed medications, worse physiologic conditions, and higher fall risk. Of them, 28 (23%) had subsequent falls. A univariate analysis showed that those with and without falls were similar in demographic characteristics, prescribed medications, physiologic function, and fall risk. There was a tendency for more falls in the nursing-care model residents (accounting for 61% of those who fell; p = 0.053). A regression analysis showed that gender (beta = 1.359; 95% confidence interval = 0.345-2.374; p = 0.010) and NPI score (beta = 0.101; 95% CI = 0.001-0.200; p = 0.047) were associated with the risk of falls. Residents at the long-term care facility had a significant risk of falls despite knowledge of their fall risk and the implementation of preventive measures. In this context of being aware of the risk, gender, and psychiatric symptoms were significantly associated with falls. Caregivers at long-term care facilities should implement further measures to prevent falls based on behavioral and psychological symptoms.

FF-MAS prevents porcine ovarian granulosa cells from hypoxia-induced apoptosis via inhibiting STAT4 expression.

Follicular fluid meiosis-activating sterol (FF-MAS) is a small molecule compound found in follicular fluid, named for its ability to induce oocyte resumption of meiosis. Granulosa cells (GCs) within the follicle are typically located in a hypoxic environment under physiologic conditions due to limited vascular distribution. Previous research suggests that hypoxia-induced cell cycle arrest and apoptosis in GCs may be crucial triggering factors in porcine follicular atresia. However, the impact of FF-MAS on GCs within follicles has not been explored so far. In this study, we uncovered a novel role of FF-MAS in facilitating GC survival under hypoxic conditions by inhibiting STAT4 expression. We found that STAT4 expression was upregulated in porcine GCs exposed to 1% O2. Both gain and loss of function assays confirmed that STAT4 was required for cell apoptosis under hypoxia conditions, and that the GC apoptosis caused by hypoxia was markedly attenuated following FF-MAS treatment through inhibition of STAT4 expression. Correlation analysis in vivo revealed that GC apoptosis was associated with increased STAT4 expression, while the FF-MAS content in follicular fluid was negatively correlated with STAT4 mRNA levels and cell apoptosis. These findings elucidate a novel role of FF-MAS-mediated protection of GCs by inhibiting STAT4 expression under hypoxia, which might contribute to the mechanistic understanding of follicular development.

Extremophiles and their expanding biotechnological applications.

Microbial life is not restricted to any particular setting. Over the past several decades, it has been evident that microbial populations can exist in a wide range of environments, including those with extremes in temperature, pressure, salinity, and pH. Bacteria and Archaea are the two most reported types of microbes that can sustain in extreme environments, such as hot springs, ice caves, acid drainage, and salt marshes. Some can even grow in toxic waste, organic solvents, and heavy metals. These microbes are called extremophiles. There exist certain microorganisms that are found capable of thriving in two or more extreme physiological conditions simultaneously, and are regarded as polyextremophiles. Extremophiles possess several physiological and molecular adaptations including production of extremolytes, ice nucleating proteins, pigments, extremozymes and exopolysaccharides. These metabolites are used in many biotechnological industries for making biofuels, developing new medicines, food additives, cryoprotective agents etc. Further, the study of extremophiles holds great significance in astrobiology. The current review summarizes the diversity of microorganisms inhabiting challenging environments and the biotechnological and therapeutic applications of the active metabolites obtained as a response to stress conditions. Bioprospection of extremophiles provides a progressive direction with significant enhancement in economy. Moreover, the introduction to omics approach including whole genome sequencing, single cell genomics, proteomics, metagenomics etc., has made it possible to find many unique microbial communities that could be otherwise difficult to cultivate using traditional methods. These findings might be capable enough to state that discovery of extremophiles can bring evolution to biotechnology.

A finely balanced order–disorder equilibrium sculpts the folding–binding landscape of an antibiotic sequestering protein

TipA, a MerR family transcription factor from Streptomyces lividans, promotes antibiotic resistance by sequestering broad-spectrum thiopeptide-based antibiotics, thus counteracting their inhibitory effect on ribosomes. TipAS, a minimal binding motif which is expressed as an isoform of TipA, harbors a partially disordered N-terminal subdomain that folds upon binding multiple antibiotics. The extent and nature of the underlying molecular heterogeneity in TipAS that shapes its promiscuous folding-function landscape is an open question and is critical for understanding antibiotic-sequestration mechanisms. Here, combining equilibrium and time-resolved experiments, statistical modeling, and simulations, we show that the TipAS native ensemble exhibits a pre-equilibrium between binding-incompetent and binding-competent substates, with the fully folded state appearing only as an excited state under physiological conditions. The binding-competent state characterized by a partially structured N-terminal subdomain loses structure progressively in the physiological range of temperatures, swells on temperature increase, and displays slow conformational exchange across multiple conformations. Binding to the bactericidal antibiotic thiostrepton follows a combination of induced-fit and conformational-selection-like mechanisms, via partial binding and concomitant stabilization of the binding-competent substate. These ensemble features are evolutionarily conserved across orthologs from select bacteria that infect humans, underscoring the functional role of partial disorder in the native ensemble of antibiotic-sequestering proteins belonging to the MerR family.