Phosphorylated RB Promotes Cancer Immunity by Inhibiting NF-κB Activation and PD-L1 Expression.

Aberrant expression of programmed death ligand-1 (PD-L1) in tumor cells promotes cancer progression by suppressing cancer immunity. The retinoblastoma protein RB is a tumor suppressor known to regulate the cell cycle, DNA damage response, and differentiation. Here, we demonstrate that RB interacts with nuclear factor κB (NF-κB) protein p65 and that their interaction is primarily dependent on CDK4/6-mediated serine-249/threonine-252 (S249/T252) phosphorylation of RB. RNA-seq analysis shows a subset of NF-κB pathway genes including PD-L1 are selectively upregulated by RB knockdown or CDK4/6 inhibitor. S249/T252-phosphorylated RB inversely correlates with PD-L1 expression in patient samples. Expression of a RB-derived S249/T252 phosphorylation-mimetic peptide suppresses radiotherapy-induced upregulation of PD-L1 and augments therapeutic efficacy of radiation in vivo. Our findings reveal a previously unrecognized tumor suppressor function of hyperphosphorylated RB in suppressing NF-κB activity and PD-L1 expression and suggest that the RB-NF-κB axis can be exploited to overcome cancer immune evasion triggered by conventional or targeted therapies.

Potassium Channels in Parkinson's Disease: Potential Roles in Its Pathogenesis and Innovative Molecular Targets for Treatment.

Parkinson's disease (PD) is a neurodegenerative disorder characterized by selective loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) region of the midbrain. The loss of neurons results in a subsequent reduction of dopamine in the striatum, which underlies the core motor symptoms of PD. To date, there are no effective treatments to stop, slow, or reverse the pathologic progression of dopaminergic neurodegeneration. This unfortunate predicament is because of the current early stages in understanding the biologic targets and pathways involved in PD pathogenesis. Ion channels have become emerging targets for new therapeutic development for PD due to their essential roles in neuronal function and neuroinflammation. Potassium channels are the most prominent ion channel family and have been shown to be critically important in PD pathology because of their roles in modulating neuronal excitability, neurotransmitter release, synaptic transmission, and neuroinflammation. In this review, members of the subfamilies of voltage-gated K+ channels, inward rectifying K+ channels, and Ca2+-activated K+ channels are described. Evidence of the role of these channels in PD etiology is discussed together with the latest views on related pathologic mechanisms and their potential as biologic targets for developing neuroprotective drugs for PD. SIGNIFICANCE STATEMENT: Parkinson's disease (PD) is the second most common neurodegenerative disorder, featuring progressive degeneration of dopaminergic neurons in the midbrain. It is a multifactorial disease involving multiple risk factors and complex pathobiological mechanisms. Mounting evidence suggests that ion channels play vital roles in the pathogenesis and progression of PD by regulating neuronal excitability and immune cell function. Therefore, they have become "hot" biological targets for PD, as demonstrated by multiple clinical trials of drug candidates targeting ion channels for PD therapy.

A novel inhalable nanobody targeting IL-4Rα for the treatment of asthma.

BACKGROUND: Inhalable biologics represent a promising approach to improve the efficacy and safety of asthma treatment. Although several mAbs targeting IL-4 receptor α chain (IL-4Rα) have been approved or are undergoing clinical trials, the development of inhalable mAbs targeting IL-4Rα presents significant challenges. OBJECTIVE: Capitalizing on the distinctive advantages of nanobodies (Nbs) in maintaining efficacy during storage and administration, we sought to develop a novel inhalable IL-4Rα Nb for effectively treating asthma. METHODS: Three IL-4Rα immunized Nb libraries were used to generate specific and functional IL-4Rα Nbs. LQ036, a bivalent Nb comprising 2 HuNb103 units, was constructed with a high affinity and specificity for human IL-4Rα. The efficacy, pharmacokinetics, and safety of inhaled LQ036 were evaluated in B-hIL4/hIL4RA humanized mice. RESULTS: LQ036 inhibited secreted embryonic alkaline phosphatase reporter activity, inhibited TF-1 cell proliferation, and suppressed phosphorylated signal transducer and activator of transduction 6 in T cells from patients with asthma. Crystal structure analysis revealed a binding region similar to dupilumab but with higher affinity, leading to better efficacy in blocking the signaling pathway. HuNb103 competed with IL-4 and IL-13 for IL-4Rα binding. Additionally, LQ036 significantly inhibited ovalbumin-specific IgE levels in serum, CCL17 levels in bronchoalveolar lavage fluid, bronchial mucous cell hyperplasia, and airway goblet cell hyperplasia in B-hIL4/hIL4RA humanized mice. Inhaled LQ036 exhibited favorable pharmacokinetics, safety, and tissue distribution, with higher concentrations observed in the lungs and bronchi. CONCLUSIONS: These findings from preclinical studies establish the safety and efficacy of inhaled LQ036, underscoring its potential as a pioneering inhalable biologic therapy for asthma.

Identification of Ligands for Ion Channels: TRPM2.

Transient receptor potential melastatin 2 (TRPM2) is a calcium-permeable, nonselective cation channel with a widespread distribution throughout the body. It is involved in many pathological and physiological processes, making it a potential therapeutic target for various diseases, including Alzheimer's disease, Parkinson's disease, and cancers. New analytical techniques are beneficial for gaining a deeper understanding of its involvement in disease pathogenesis and for advancing the drug discovery for TRPM2-related diseases. In this work, we present the application of collision-induced affinity selection mass spectrometry (CIAS-MS) for the direct identification of ligands binding to TRPM2. CIAS-MS circumvents the need for high mass detection typically associated with mass spectrometry of large membrane proteins. Instead, it focuses on the detection of small molecules dissociated from the ligand-protein-detergent complexes. This affinity selection approach consolidates all affinity selection steps within the mass spectrometer, resulting in a streamlined process. We showed the direct identification of a known TRPM2 ligand dissociated from the protein-ligand complex. We demonstrated that CIAS-MS can identify binding ligands from complex mixtures of compounds and screened a compound library against TRPM2. We investigated the impact of voltage increments and ligand concentrations on the dissociation behavior of the binding ligand, revealing a dose-dependent relationship.

Association of long-term triglyceride-glucose index patterns with the incidence of chronic kidney disease among non-diabetic population: evidence from a functional community cohort.

BACKGROUND: The triglyceride-glucose (TyG) index is a reliable surrogate marker of insulin resistance and previous studies have confirmed the association of TyG index with incident chronic kidney disease (CKD). However, the impact of longitudinal patterns of TyG index on CKD risk among non-diabetic population is still unknown. Therefore, this study aimed to investigate the association of longitudinal patterns of TyG index with incident CKD among non-diabetic population. METHODS: A total of 5484 non-diabetic participants who underwent one health examination per year from 2015 to 2017 were included in this prospective study. TyG index variability and cumulative TyG index were calculated to assess the longitudinal patterns of TyG index. Cox proportional hazard models were performed to estimate the association of TyG index variability or cumulative TyG index with incident CKD. RESULTS: During a median of 3.82 years follow-up, 879 participants developed CKD. Compared with participants in the lowest quartile, the hazard ratio (HR) and 95% confidence interval (CI) of incident CKD were 1.772 (95% CI: 1.453, 2.162) for the highest TyG index variability quartile and 2.091 (95% CI: 1.646, 2.655) for the highest cumulative TyG index quartile in the fully adjusted models. The best discrimination and reclassification improvement were observed after adding baseline TyG, TyG index variability and cumulative TyG index to the clinical risk model for CKD. CONCLUSIONS: Both TyG index variability and cumulative TyG index can independently predict incident CKD among non-diabetic population. Monitoring longitudinal patterns of TyG index may assist with prediction and prevention of incident CKD.

Elevated Glucose on Admission Was an Independent Risk Factor for 30-Day Major Adverse Cardiovascular Events in Patients with STEMI but Not NSTEMI.

Background: The purpose of this study was to evaluate the impact of glucose levels on admission, on the risk of 30-day major adverse cardiovascular events (MACEs) in patients with acute myocardial infarction (AMI), and to assess the difference in outcome between ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI) patients. Methods: This study was a post hoc analysis of the Acute Coronary Syndrome Quality Improvement in Kerala Study, and 13,398 participants were included in the final analysis. Logistic regression models were used to assess the association between glucose levels on admission and the risk of 30-day MACEs, adjusting for potential confounders. Results: Participants were divided according to the glucose quintiles. There was a positive linear association between glucose levels at admission and the risk of 30-day MACEs in AMI patients [adjusted OR (95% CI): 1.05 (1.03, 1.07), p < 0.001]. Compared to participants with an admission glucose between 5.4 and 6.3 mmol/L, participants with the highest quintile of glucose level ( ≥ 10.7 mmol/L) were associated with increased risk of 30-day MACEs in the fully adjusted logistic regression model [adjusted OR (95% CI): 1.82 (1.33, 2.50), p < 0.001]. This trend was more significant in patients with STEMI (p for interaction = 0.036). Conclusions: In patients with AMI, elevated glucose on admission was associated with an increased risk of 30-day MACEs, but only in patients with STEMI.

Targeting the sulfur-containing amino acid pathway in leukemia.

sulfur-containing amino acids have been reported to patriciate in gene regulation, DNA methylation, protein synthesis and other physiological or pathological processes. In recent years, metabolism-related molecules of sulfur-containing amino acids affecting the occurrence, development and treatment of tumors have been implicated in various disorders, especially in leukemia. Here, we summarize current knowledge on the sulfur-containing amino acid metabolism pathway in leukemia and examine ongoing efforts to target this pathway, including treatment strategies targeting (a) sulfur-containing amino acids, (b) metabolites of sulfur-containing amino acids, and (c) enzymes and cofactors related to sulfur-containing amino acid metabolism in leukemia. Future leukemia therapy will likely involve innovative strategies targeting the sulfur-containing amino acid metabolism pathway.

Biosensor Based on ZIF-67-HRP and MWCNTs Nanocomposite Modified Glass Carbon Electrode for the Detection of Luteolin in Vegetables.

Luteolin has various pharmacological properties, including anti-inflammatory, antioxidant, and antitumor characteristics. Due to its potential value in drugs and functional foods, it is important to develop an efficient method for detecting luteolin. In this work, the poor selectivity of existing luteolin nonenzymatic sensors was solved by translating the enzyme-catalyzed reaction from bulk solution to the surface of a horseradish peroxidase (HRP) modified electrode through an electrocatalytic oxidation process. Here, we modified the surface of a glassy carbon electrode (GCE) with metal-organic frameworks (MOFs; ZIF-67 here, abbreviated as ZIF), functional nanomaterials, and HRP and finally covered it with Nafion (NF). In this case, luteolin acts as a hydrogen donor, and the electrode acts as a hydrogen acceptor; the oxidation reaction occurs on the electrode surface. The use of ZIF-67 ensured the conformational stability of HRP to ensure the selectivity and anti-interference property, and SDS-dispersed multiwalled carbon nanotubes (MWCNTs) enhanced the electrode conductivity. The use of NF avoids shedding of the electrode material during the testing process. A UV-vis spectrophotometer was used to study the selectivity of luteolin by HRP and the compatibility between HRP and ZIF. The materials were characterized and analyzed by scanning electron microscopy and transmission electron microscopy. Due to the synergistic effect of these nanomaterials, the linear range of NF/ZIF-HRP/MWCNTs-SDS/GCE was 1.0 × 10-2 to 6.0 µM, with detection limits of 25.3 nM (S/N = 3). The biosensor showed long-term stability and reproducibility, with a relative standard deviation of 4.2% for the peak current (n = 5). Finally, the biosensor was successfully used to detect luteolin in carrots, celery, and cauliflower.

I2-DMSO-Mediated Construction of 2,3- and 2,4-Disubstituted Pyrimido[1,2-b]indazole Skeletons.

An efficient synthetic method for constructing 2,3- and 2,4-disubstituted pyrimidio[1,2-b]indazole skeletons through I2-DMSO-mediated and substrate-controlled regioselective [4 + 2] cyclization is reported. The reaction conditions are mild, its operation is simple, and the substrate scope is wide. More than 60 pyrimidio[1,2-b]indazole derivatives have been synthesized, providing a new methodology for constructing related molecules and potentially enriching bioactive-molecule libraries.

Proteomic insights into the response of Halomonas sp. MNB13 to excess Mn(â ¡) and the role of H2S in Mn(â ¡) resistance.

Halomonas spp. are moderately halophilic bacteria with the ability to tolerate various heavy metals. However, the role of basic cellular metabolism, particularly amino acid metabolism, has not been investigated in Halomonas spp. under excess Mn(Ⅱ). The strain Halomonas sp. MNB13 was isolated from a deep-sea ferromanganese nodule and can tolerate 80 mM Mn(Ⅱ). To comprehensively explore the mechanisms underlying its resistance to excess Mn(Ⅱ), we conducted a comparative proteome analysis. The data revealed that both 10 mM and 50 mM Mn(Ⅱ) significantly up-regulated the expression of proteins involved in Mn(Ⅱ) transport (MntE), oxidative stress response (alkyl hydroperoxide reductase and the Suf system), and amino acid metabolism (arginine, cysteine, methionine, and phenylalanine). We further investigated the role of cysteine metabolism in Mn(Ⅱ) resistance by examining the function of its downstream product, H2S. Consistent with the up-regulation of cysteine desulfurase, we detected an elevated level of H2S in Halomonas sp. MNB13 cells under Mn(Ⅱ) stress, along with increased intracellular levels of H2O2 and O2•-. Upon exogenous addition of H2S, we observed a significant restoration of the growth of Halomonas sp. MNB13. Moreover, we identified decreased intracellular levels of H2O2 and O2•- in MNB13 cells, which coincided with a decreased formation of Mn-oxides during cultivation. In contrast, in cultures containing NaHS, the residual Mn(Ⅱ) levels were higher than in cultures without NaHS. Therefore, H2S improves Mn(Ⅱ) tolerance by eliminating intracellular reactive oxygen species rather than decreasing Mn(Ⅱ) concentration in solution. Our findings indicate that cysteine metabolism, particularly the intermediate H2S, plays a pivotal role in Mn(Ⅱ) resistance by mitigating the damage caused by reactive oxygen species. These findings provide new insights into the amino acid mechanisms associated with Mn(Ⅱ) resistance in bacteria.

Association between systemic immune inflammatory/inflammatory response index and hypertension: A cohort study of functional community.

BACKGROUND AND AIMS: In prospective studies, there is limited evidence of the association between inflammation and hypertension. We aimed to explore the relationship between systemic immune inflammatory index (SII)/systemic inflammatory response index (SIRI) and hypertension in a prospective cohort study to identify the best inflammatory cell markers that predict hypertension. METHODS AND RESULTS: This study was conducted in a functional community cohort in Beijing. In 2015, a total of 6003 individuals without hypertension were recruited and followed up until 2021. Using a restriction cubic spline with baseline SII/SIRI as a continuous variable, the dose-response relationship between hypertension and SII/SIRI was explored. Logistic regression was used to analyze the correlation between hypertension and SII/SIRI trajectory groups. At a mean follow-up of 6 years, 970 participants developed hypertension. SII showed a significant nonlinear dose-response relationship with hypertension (P < 0.05). Higher SII/SIRI was associated with an increased risk of hypertension (SII: RR = 1.003, 95%CI: 1.001-1.004; SIRI: RR = 1.228, 95%CI: 1.015-1.486). Both SII and SIRI were more predictive in males than females (SII: 0.698 vs. 0.695; SIRI: 0.686 vs. 0.678). CONCLUSION: Both systemic immune inflammatory index (SII) and systemic inflammatory response Index (SIRI) independently increased the risk of hypertension, and both were effective inflammatory cell indicators that predict the risk of hypertension.

A humanized trivalent Nectin-4-targeting nanobody drug conjugate displays potent antitumor activity in gastric cancer.

BACKGROUND: Gastric cancer represents a highly lethal malignancy with an elevated mortality rate among cancer patients, coupled with a suboptimal postoperative survival prognosis. Nectin-4, an overexpressed oncological target for various cancers, has been exploited to create antibody-drug conjugates (ADCs) to treat solid tumors. However, there is limited research on Nectin-4 ADCs specifically for gastric cancer, and conventional immunoglobulin G (IgG)-based ADCs frequently encounter binding site barriers. Based on the excellent tumor penetration capabilities inherent in nanobodies (Nbs), we developed Nectin-4-targeting Nb drug conjugates (NDCs) for the treatment of gastric cancer. RESULTS: An immunized phage display library was established and employed for the selection of Nectin-4-specific Nbs using phage display technology. Subsequently, these Nbs were engineered into homodimers to enhance Nb affinity. To prolong in vivo half-life and reduce immunogenicity, we fused an Nb targeting human serum albumin (HSA), resulting in the development of trivalent humanized Nbs. Further, we site-specifically conjugated a monomethyl auristatin E (MMAE) at the C-terminus of the trivalent Nbs, creating Nectin-4 NDC (huNb26/Nb26-Nbh-MMAE) with a drug-to-antibody ratio (DAR) of 1. Nectin-4 NDC demonstrated excellent in vitro cell-binding activities and cytotoxic efficacy against cells with high Nectin-4 expression. Subsequent administration of Nectin-4 NDC to mice bearing NCI-N87 human gastric cancer xenografts demonstrated rapid tissue penetration and high tumor uptake through in vivo imaging. Moreover, Nectin-4 NDC exhibited noteworthy dose-dependent anti-tumor efficacy in in vivo studies. CONCLUSION: We have engineered a Nectin-4 NDC with elevated affinity and effective tumor uptake, further establishing its potential as a therapeutic agent for gastric cancer.

Synthesis and Hypoglycemic Effect of Insulin from the Venom of Sea Anemone Exaiptasia diaphana.

Sea anemone venom, abundant in protein and peptide toxins, serves primarily for predatory defense and competition. This study delves into the insulin-like peptides (ILPs) present in sea anemones, particularly focusing on their role in potentially inducing hypoglycemic shock in prey. We identified five distinct ILPs in Exaiptasia diaphana, exhibiting varied sequences. Among these, ILP-Ap04 was successfully synthesized using solid phase peptide synthesis (SPPS) to evaluate its hypoglycemic activity. When tested in zebrafish, ILP-Ap04 significantly reduced blood glucose levels in a model of diabetes induced by streptozotocin (STZ) and glucose, concurrently affecting the normal locomotor behavior of zebrafish larvae. Furthermore, molecular docking studies revealed ILP-Ap04's unique interaction with the human insulin receptor, characterized by a detailed hydrogen-bonding network, which supports a unique mechanism for its hypoglycemic effects. Our findings suggest that sea anemones have evolved sophisticated strategies to activate insulin receptors in vertebrates, providing innovative insights into the design of novel drugs for the treatment of diabetes.

Phantom study of a self-shielded X-ray bone age assessment instrument against scattered radiation in children.

Hand-wrist radiography is the most common and accurate method for evaluating children's bone age. To reduce the scattered radiation of radiosensitive organs in bone age assessment, we designed a small X-ray instrument with radioprotection function by adding metal enclosure for X-ray shielding. We used a phantom operator to compare the scattered radiation doses received by sensitive organs under three different protection scenarios (proposed instrument, radiation personal protective equipment, no protection). The proposed instrument showed greater reduction in the mean dose of a single exposure compared with radiation personal protective equipment especially on the left side which was proximal to the X-ray machine (≥80.0% in eye and thyroid, ≥99.9% in breast and gonad). The proposed instrument provides a new pathway towards more convenient and efficient radioprotection.

Release characteristics and risk assessment of volatile sulfur compounds in a municipal wastewater treatment plant with odor collection device.

Due to the malodorous effects and health risks of volatile sulfur compounds (VSCs) emitted from wastewater treatment plants (WWTPs), odor collection devices have been extensively utilized; however, their effectiveness has rarely been tested. In the present investigation, the characteristics of VSCs released in a WWTP equipped with gas collection hoods are methodically examined by gas chromatography. The obtained results indicate that the concentration of VSCs in the ambient air can be substantially reduced, and the primary treatment unit still achieves the highest concentration of VSCs. Compared to WWTPs without odor collection devices, the concentration of H2S in this WWTP is not dominant, but its sensory effects and health risks are still not negligible. Additionally, research on the emission of VSCs from sludge reveals that the total VSCs emitted from dewatering sludge reaches the highest level. Volatile organic sulfur compounds play a dominant role in the component and sensory effects of VSCs released by sludge. This study provides both data and theoretical support for analyzing the effectiveness of odor collection devices in WWTPs, as well as reducing the source of VSCs. The findings can be effectively employed to optimize these devices and improve their performance.

Chlorogenic Acid Attenuates Isoproterenol Hydrochloride-Induced Cardiac Hypertrophy in AC16 Cells by Inhibiting the Wnt/ß-Catenin Signaling Pathway.

Cardiac hypertrophy (CH) is an important characteristic in heart failure development. Chlorogenic acid (CGA), a crucial bioactive compound from honeysuckle, is reported to protect against CH. However, its underlying mechanism of action remains incompletely elucidated. Therefore, this study aimed to explore the mechanism underlying the protective effect of CGA on CH. This study established a CH model by stimulating AC16 cells with isoproterenol (Iso). The observed significant decrease in cell surface area, evaluated through fluorescence staining, along with the downregulation of CH-related markers, including atrial natriuretic peptide (ANP), brain natriuretic peptide (BNP), and ß-myosin heavy chain (ß-MHC) at both mRNA and protein levels, provide compelling evidence of the protective effect of CGA against isoproterenol-induced CH. Mechanistically, CGA induced the expression of glycogen synthase kinase 3ß (GSK-3ß) while concurrently attenuating the expression of the core protein ß-catenin in the Wnt/ß-catenin signaling pathway. Furthermore, the experiment utilized the Wnt signaling activator IM-12 to observe its ability to modulate the impact of CGA pretreatment on the development of CH. Using the Gene Expression Omnibus (GEO) database combined with online platforms and tools, this study identified Wnt-related genes influenced by CGA in hypertrophic cardiomyopathy (HCM) and further validated the correlation between CGA and the Wnt/ß-catenin signaling pathway in CH. This result provides new insights into the molecular mechanisms underlying the protective effect of CGA against CH, indicating CGA as a promising candidate for the prevention and treatment of heart diseases.

Intrinsic capacity loss rates and protective factors among individuals aged 80 years and older in Chinese nursing homes: A latent class analysis.

Prior to this cross-sectional study, the intrinsic capacity (IC) loss rates and protective factors in nursing homes for individuals aged 80 and older remained unexplored. Analysing 434 participants, this study found 86.9 % of individuals experienced the loss of at least one IC domain, with detailed losses in locomotion, vision, vitality, hearing, psychological, and cognitive capacities at rates of 83.2 %, 52.8 %, 50.9 %, 46.5 %, 44.9 %, and 44.0 %, respectively. Following latent class analysis (LCA), five distinct IC impairment patterns were noted, with locomotor impairment emerging as a central component across most classes. IC protective factors for persons aged 80 years and older included financial stability, being male or younger within the cohort, junior high school or higher education, being married, no smoking history, manageable comorbidity levels, minimal medication use, good sleep, and not using assistive devices. Based on these five classes, this study provides a potential practical framework alongside recommendations for IC care strategies in the oldest-old, emphasising the importance of locomotor function in maintaining the overall IC.

Dual-Site Bridging Mechanism for Bimetallic Electrochemical Oxygen Evolution.

Heterogeneous dual-site electrocatalysts are emerging cutting-edge materials for efficient electrochemical water splitting. However, the corresponding oxygen evolution reaction (OER) mechanism on these materials is still unclear. Herein, based on a series of in-situ spectroscopy experiments and density function theory (DFT) calculations, a new heterogeneous dual-site O-O bridging mechanism (DSBM) is proposed. This mechanism is to elucidate the sequential appearance of dual active sites through in-situ construction (hybrid ions undergo reconstruction initially), determine the crucial role of hybrid dual sites in this mechanism (with Ni sites preferentially adsorbing hydroxyls for catalysis followed by proton removal at Fe sites), assess the impact of O-O bond formation on the activation state of water (inducing orderliness of activated water), and investigate the universality (with Co doping in Ni(P4O11)). Under the guidance of this mechanism, with Fe-Ni(P4O11) as pre-catalyst, the in-situ formed Fe-Ni(OH)2 electrocatalyst has reached a record-low overpotential of 156.4 mV at current density of 18.0 mA cm-2. Successfully constructed Fe-Ni(P4O11)/Ti uplifting the overall efficacy of the phosphate from moderate to superior, positioning it as an innovative and highly proficient electrocatalyst for OER.

Structural Basis of the Bivalency of the TRPV1 Agonist DkTx.

Bivalency is a prevalent natural mechanism to enhance receptor avidity. Various two-domain disulfide-rich peptides exhibiting bivalent action have been identified from animal venoms. A unique characteristic of these peptides is that they induce a pharmacological response different from that provoked by any of the constituent domains. The enhanced potency and avidity of such peptides is therefore a consequence of their domain fusion by a peptide linker. The role of the linker itself, beyond conjugation, remains unclear. Here, we investigate how the linker affects the bivalency of the capsaicin receptor (TRPV1) agonist DkTx. We recombinantly produced isotope labelled DkTx using a protein splicing approach, to solve the high-resolution solution structure of DkTx, revealing residual linker order stabilised by linker-domain interactions leading to biased domain orientations. The significance of this was studied using a combination of mutagenesis, spin relaxation studies and electrophysiology measurements. Our results reveal that disrupting the pre-organisation of the domains of DkTx is accompanied by reductions in potency and onset of avidity. Our findings support a model of pre-configured two-domain binding, in favour of the previously suggested sequential binding model. This highlights the significance of ordered elements in linker design and the natural evolution of these in bivalent toxins.

MoS2 Hollow Multishelled Nanospheres Doped Fe Single Atoms Capable of Fast Phase Transformation for Fast-charging Na-ion Batteries.

Low Na+ and electron diffusion kinetics severely restrain the rate capability of MoS2 as anode for sodium-ion batteries (SIBs). Slow phase transitions between 2H and 1T, and from NaxMoS2 to Mo and Na2S as well as the volume change during cycling, induce a poor cycling stability. Herein, an original Fe single atom doped MoS2 hollow multishelled structure (HoMS) is designed for the first time to address the above challenges. The Fe single atom in MoS2 promotes the electron transfer, companying with shortened charge diffusion path from unique HoMS, thereby achieving excellent rate capability. The strong adsorption with Na+ and self-catalysis of Fe single atom facilitates the reversible conversion between 2H and 1T, and from NaxMoS2 to Mo and Na2S. Moreover, the buffering effect of HoMS on volume change during cycling improves the cyclic stability. Consequently, the Fe single atom doped MoS2 quadruple-shelled sphere exhibits a high specific capacity of 213.3 mAh g-1 at an ultrahigh current density of 30 A g-1, which is superior to previously-reported results. Even at 5 A g-1, 259.4 mAh g-1 (83.68 %) was reserved after 500 cycles. Such elaborate catalytic site decorated HoMS is also promising to realize other "fast-charging" high-energy-density rechargeable batteries.