Tertiary Complex Research Articles

Ixochymostatin, a trypsin inhibitor-like (TIL) protein from Ixodes scapularis, inhibits chymase and impairs vascular permeability

Ticks obtain a blood meal by lacerating small blood vessels and ingesting the blood that flows to the feeding site, which triggers various host responses. However, ticks face the challenge of wound healing, a process involving hemostasis, inflammation, cell proliferation and migration, and remodeling, hindering blood acquisition. To overcome these obstacles, tick salivary glands produce an array of bioactive molecules. Here, we characterize ixochymostatin, an Ixodes scapularis protein belonging to the trypsin inhibitor-like (TIL) family. It is expressed in multiple developmental stages and in tick salivary glands and acts as a slow and tight-binding inhibitor of chymase, cathepsin G, and chymotrypsin. Predictions for the tertiary structure complex between ixochymostatin and chymase suggest a direct interaction between the inhibitor reactive site loop and protease active sites. In vitro, ixochymostatin protects the endothelial cell barrier against chymase degrading action, decreasing cell permeability. In vivo, it reduces vascular permeability induced by chymase and compound 48/80, a mast cell degranulator agonist, in a mouse model. Additionally, ixochymostatin inhibits the chymase-dependent generation of vasoconstrictor peptides. Antibodies against ixochymostatin neutralize its inhibitory properties, with epitope mapping identifying potential neutralization regions. Ixochymostatin emerges as a novel tick protein modulating host responses against tick feeding, facilitating blood acquisition.

Magma Degassing andGoldMineralizationinthe Alkaline Intrusion- HostedGiltEdgeGoldDeposit,NorthernBlackHills, SouthDakota,USA

Gold mineralization in the Gilt Edge deposit was closely associated with magmatic differentiation and the formation of a Tertiary alkaline intrusive complex within the Lead–Deadwood dome.. Fluid inclusions and trace element geochemistry were used to study fluid evolution and determine sources. Quartz disseminated in unaltered trachyte porphyry hosts two populations of primary inclusions: 1) hypersaline i S–L–V a red hematite crystal and 2) mixtures of L–V and V– L that record phase separation at ~700oC. Whereas samples of hydrothermal quartz collected from in ore zones within and beyond structures (e.g., fault and breccia zones) contain dominant populations of V–L and L–V inclusions, respectively. Mineralization in structures formed from complex fluids of magmatic origin based on inclusions containing five transparent salt crystals and opaque crystals with cubic and round habits that have homogenization temperatures (Th) 650oC and salinities 63 wt.% NaCl equiv. In contrast, broader areas of disseminated mineralization in argillized and propylitized rocks contain hydrothermal quartz hosting large populations of L–V inclusions with Th of 200o360oC and salinities of 10–30 wt.% NaCl equiv., which reflect fluid mixing. Trace element concentrations are significantly higher in samples from structures and define zones of near surface Ag–As–Zn–Pb and deep Au–W–Mo–Cu. Whereas low trace element concentrations characterize propylitized quartz trachyte porphyry, except for high concentrations of Sb and Hg that occur at depth and likely track the retreat of isotherms as the hydrothermal system collapsed. These data show that during differentiation in a deep magma chamber, volatile-rich low-density fluids were periodically degassed into preexisting structures that were reactivated. Gold deposition during four stages of mineralization likely occurred due to boiling, changes in oxygen fugacity, and fluid mixing.

Caregiver and Care Team Perceptions of Online Collaborative Care Planning for CMC.

Care plans summarize a child with medical complexity's (CMC) medical history and ongoing care needs. Often, the health care team controls the care plan content, limiting caregivers' ability to edit the document in real time and potentially compromising accuracy and utility. With this study, we aimed to provide caregivers of CMC with online access and shared editing control of their child's care plan and to explore the experiences of caregivers and care team members (CTMs) after using an online collaborative care plan (OCCP). Caregivers of CMC were recruited from a tertiary complex care program to use an online, patient-facing platform for 6 months, which included the ability to edit and share their child's care plan. Caregivers and CTMs participated in semi-structured interviews to explore their experiences in using the OCCP. Consistent with grounded theory methodology, a constant comparative analysis was used, which allowed for theoretical sampling and theory generation. A total of 15 caregivers and 20 CTMs completed interviews. Interviews revealed 3 major themes and 9 subthemes, including (1) the navigation of uncharted roles (trust, responsibility), (2) the requirements for success (electronic medical record integration, online access, collaborative care plan review), and (3) cohesive care (accessibility and convenience, being on the same page, autonomy). Themes informed the creation of a theoretical model for the implementation and utility of OCCPs. Online, collaborative care plans, when implemented safely and thoughtfully, promote shared understanding, improve caregiver autonomy, and increase the accessibility of health information. Together, these benefits facilitate cohesive care and authentic partnership between caregivers and CTMs in the care of CMC.

1-Deoxy-d-xylulose 5-phosphate reductoisomerase as target for anti Toxoplasma gondii agents: crystal structure, biochemical characterization and biological evaluation of inhibitors.

Toxoplasma gondii is a widely distributed apicomplexan parasite causing toxoplasmosis, a critical health issue for immunocompromised individuals and for congenitally infected foetuses. Current treatment options are limited in number and associated with severe side effects. Thus, novel anti-toxoplasma agents need to be identified and developed. 1-Deoxy-d-xylulose 5-phosphate reductoisomerase (DXR) is considered the rate-limiting enzyme in the non-mevalonate pathway for the biosynthesis of the isoprenoid precursors isopentenyl pyrophosphate and dimethylallyl pyrophosphate in the parasite, and has been previously investigated for its key role as a novel drug target in some species, encompassing Plasmodia, Mycobacteria and Escherichia coli. In this study, we present the first crystal structure of T. gondii DXR (TgDXR) in a tertiary complex with the inhibitor fosmidomycin and the cofactor NADPH in dimeric conformation at 2.5 Å resolution revealing the inhibitor binding mode. In addition, we biologically characterize reverse α-phenyl-β-thia and β-oxa fosmidomycin analogues and show that some derivatives are strong inhibitors of TgDXR which also, in contrast with fosmidomycin, inhibit the growth of T. gondii in vitro. Here, ((3,4-dichlorophenyl)((2-(hydroxy(methyl)amino)-2-oxoethyl)thio)methyl)phosphonic acid was identified as the most potent anti T. gondii compound. These findings will enable the future design and development of more potent anti-toxoplasma DXR inhibitors.

Preparation and evaluation of novel biodegradable Kombucha cellulose-based multi-layered composite tableware

A huge volume of single-use plastics is used for food packaging and cutlery which is associated with significant negative environmental impacts. In this study, the facile fabrication of multilayered composites using kombucha cellulose (KC) intercalated with tannery waste-gelatin as bio-adhesive using layer-by-layer assembly followed by hydraulic heat compression technique is reported. The prolonged fermentation of Kombucha tea resulted in KC pellicle with productivity of 385.5 ± 71.4 g/L and thickness of 2 ± 0.7 cm. The purification process improved the crystallinity index of the KC layer from 41.17% to 86.2%. Gelatin prepared using tannery trimming waste along with glucose at varying concentrations was used as interlayer coating between cellulose layers crosslinked by Maillard reactions resulting in the formation of biologically benevolent ‘melanoidins’. Heat crosslinked composite (S8–20 H) with 8 layers of KC held with gelatin-glucose-myrobalan tertiary complex exhibited a high tensile strength of 47.7 MPa and a flexural strength of 117.27 MPa indicating high mechanical stiffness with the least density value of 0.71 g/cm3. The hardness values of the composites were between 54 and 76.6 Shore D hardness. The moisture susceptibility and thermal stability of the composites were found to be optimum for its use as cutlery. The composites were shaped into spoon-like tableware, ergonomically designed to appease, with baked food-like color, texture, and fragrance. The aqueous tolerance and surface oil resistance exhibited by the tableware were superior to traditional wood-based cutlery. By mechanical disintegration, the tableware is fully recyclable as a value-added bio-fertilizer for effective plant growth. This work presents a sustainable waste-to-wealth approach towards the preparation of food-safe, environment–friendly and biodegradable substitutes for plastics intended for tableware applications.

RNAscape: geometric mapping and customizable visualization of RNA structure.

Analyzing and visualizing the tertiary structure and complex interactions of RNA is essential for being able to mechanistically decipher their molecular functions in vivo. Secondary structure visualization software can portray many aspects of RNA; however, these layouts are often unable to preserve topological correspondence since they do not consider tertiary interactions between different regions of an RNA molecule. Likewise, quaternary interactions between two or more interacting RNA molecules are not considered in secondary structure visualization tools. The RNAscape webserver produces visualizations that can preserve topological correspondence while remaining both visually intuitive and structurally insightful. RNAscape achieves this by designing a mathematical structural mapping algorithm which prioritizes the helical segments, reflecting their tertiary organization. Non-helical segments are mapped in a way that minimizes structural clutter. RNAscape runs a plotting script that is designed to generate publication-quality images. RNAscape natively supports non-standard nucleotides, multiple base-pairing annotation stylesand requires no programming experience. RNAscape can also be used to analyze RNA/DNA hybrid structures and DNA topologies, including G-quadruplexes. Users can upload their own three-dimensional structures or enter a Protein Data Bank (PDB) ID of an existing structure. The RNAscape webserver allows users to customize visualizations through various settings as desired. URL: https://rnascape.usc.edu/.

Design and synthesis of nucleic acid nano-environment interactome-targeting small molecule PROTACs and their anticancer activity.

Targeted protein degradation through PROteolysis TArgeting Chimeras (PROTACs) is a relatively new modality in cellular interventions. The minimum requirement for PROTACs to function is forming a tertiary complex of the protein of interest (POI), E3 ligase, and the molecular glue PROTAC. Here, we propose a new approach to modulate the nano-environment interactome of a non-protein target through a plausible quaternary complex of interactome-biomolecule of interest (BOI)-PROTAC and E3 ligase. We report nucleic acid-targeting PROTAC (NA-TAC) molecules by conjugating DNA-binding and E3 ligase ligands. We demonstrate that NA-TACs can target the G-quadruplex DNA and induce elevated DNA damage and cytotoxicity compared to the conventional G-quadruplex binding ligands. Our new class of NA-TACs lays the foundation for small molecule-based non-protein targeting PROTACs for interactome and nanoenvironment mapping and nucleic acid-targeted precision medicines.

A novel fluorescent aptasensor for the detection of theophylline based on cryonase-driven signal amplification strategy.

In the study, we have developed an expedient and efficient method for the detection of theophylline based on the amplification of the signal intensity of fluorescence based on oxidized single-walled carbon nanohorns (oxSWCNHs)/cryonase. When theophylline was not present in the system, oxSWCNHs can adequately adsorb nucleic acid probes labeled by carboxyfluorescein (FAM). In the presence of theophylline, the nucleic acid probe forms the tertiary probe-theophylline complex, which detaches from the surface of the oxSWCNHs. Then, upon reaction with cryonase, the complex can release the FAM and theophylline into the next cycle. The fluorescence signal of the system exhibits a 1:N magnification, enabling quantitative detection of theophylline. The linear range was 30-150 ng/mL, and the limit of detection (LOD) was 6.04 ng/mL. At the same time, it can also be used to detect theophylline in mouse serum.

Selenite ameliorates the ATP hydrolysis of mitochondrial F1FO-ATPase by changing the redox state of thiol groups and impairs the ADP phosphorylation

Selenite as an inorganic form of selenium can affect the redox state of mitochondria by modifying the thiol groups of cysteines. The F1FO-ATPase has been identified as a mitochondrial target of this compound. Indeed, the bifunctional mechanism of ATP turnover of F1FO-ATPase was differently modified by selenite. The activity of ATP hydrolysis was stimulated, whereas the ADP phosphorylation was inhibited. We ascertain that a possible new protein adduct identified as seleno-dithiol (-S-Se-S-) mercaptoethanol-sensitive caused the activation of F-ATPase activity and the oxidation of free –SH groups in mitochondria. Conversely, the inhibition of ATP synthesis by selenite might be irreversible. The kinetic analysis of the activation mechanism was an uncompetitive mixed type with respect to the ATP substrate. Selenite bound more selectively to the F1FO-ATPase loaded with the substrate by preferentially forming a tertiary (enzyme-ATP-selenite) complex. Otherwise, the selenite was a competitive mixed-type activator with respect to the Mg2+ cofactor. Thus, selenite more specifically bound to the free enzyme forming the complex enzyme-selenite. However, even if the selenite impaired the catalysis of F1FO-ATPase, the mitochondrial permeability transition pore phenomenon was unaffected. Therefore, the reversible energy transduction mechanism of F1FO-ATPase can be oppositely regulated by selenite.

Targeted Pubic Neoantigen Immunotherapy Using Encapsulated Nanoparticles, Directed by Radiation

We tested a treatment combining radiotherapy with pubic neoantigen nanoparticles of CAND1 and ADGRF5-II (120 ± 56 nm) in nanocapsules detectable by computed tomography (CT) (545± 24 nm) with IFN γ or PD-L1 antibody (Ab), which released their contents upon radiation exposure. We performed two radiotherapy sessions: 1) induction of MHC-I and II in tumor cells and dendritic cells (DC) by the first round of radiation with concurrently released IFN γ from nanoparticles; 2) targeted neoantigen immunotherapy with PD-L1 blockade by the second round of radiation, elicited by CAND1-specific CD8+T-cell and ADGRF5-II-specific CD4+T-cell, related to induced MHC-I and MHC-II in session 1, respectively. For session one, nanocapsules were generated by mixing iopamiron and 15 mg IFN γ with a 1.0 mL solution containing 4.0% alginate, 3.0% hyaluronate, and 1 μg/mL P-selectin. This mixture was sprayed into 0.5 mmol/l FeCl2 supplemented with 1 µg/mL anti-VEGFR-1/2 Ab. For session two, Mixture of 110 fmol CAND1 and fmol ADGRF5-II, were encapsulated into poly lactic-co-Glycolic acid (PLGA) particle, using nanoprecitation method. Those particles were encapsulated by mixing into above alginate-hyaluronate cocktail with 400 mg PD-L1 antibody (Ab), then sprayed into 0.5 mmol/l FeCl2 supplemented with P-selectin Ab. In session one, 1 × 1010 nanocapsules were intravenously injected into BALB/c mice exhibiting primary 4TI mammary carcinoma in the left hind leg and lung metastases. Tumor accumulation was monitored by CT. Subsequently, 10 or 20 Gy 60Co γ-radiation was administered to primary tumors and lung metastasis. In session two, 1 × 1010 nanocapsules were injected i.v. and allowed to interact with P-selectin for 24 h; a further 10 or 20 Gy 60Co γ-radiation was administered to tumors and lung metastasis. In session one, CT imaged the accumulation of anti-VEGFR-1/2 nanocapsules around primary and metastatic tumors, which helped determine the timing of the first radiation. The nanocapsules released P-selectin and IFN γ in response to first radiation. P-selectin was deposited on tumor vessels. Radiation and released IFN γ elicited MHC-I and II on tumor cells and DCs. In session two, released CAND1 and ADGRF5-II from PLGA particle, which were emitted from nanocapsules upon second radiation, were loaded onto MHC-I and II. Subsequently, two kinds of tertiary complex were formed on tumor cells and DC: 1) MHC-I-CAND1-CD8+T-cell receptor (TCR); and 2) MHC-II- ADGRF5-II-CD4+TCR, which destroyed tumor cells, in collaboration with released PD-L1 Ab. Those T-cell mediated cell killing was magnified via enhanced DC-mediated T-cell priming by the two kinds of tertiary complex on DC. Those treatments resulted in EF 1.5 and 86% reduction of new metastasis formation. Our encapsulated pubic neoantigen particle will lead to quick and effective neoantigen immunotherapy.

Ten years of a geriatric oncology service at a public university cancer centre in Brazil.

The implementation of a geriatric oncology service is challenging in both high-income and low-and-middle-income countries. The Octavio Frias de Oliveira Institute of Cancer of Sao Paulo (ICESP) is a tertiary healthcare complex of the Clinics Hospital of the University of Sao Paulo Medical School and is considered a model of excellence in oncology in Latin America. The objective of this manuscript is to describe 10 years of the geriatric oncology service at ICESP and the challenges for its implementation. We performed a narrative description of the ICESP's geriatric oncology service and a general retrospective descriptive analysis of data collected from routine structured medical records of patients referred to the service from 2011 to 2021. This article highlights the different settings in which the service operates (outpatient, pre-operative and hospital follow-up). In this period, 1,700 patients were assessed for preoperative evaluation (median age 83.9, SD 4.95), 468 patients were evaluated for therapeutic decision (median age 79.4, SD 7.38), 968 in general geriatric oncology care outpatient clinics from 2012 to 2021 (median age 78.7, SD 7.91) and 1,391 inpatient evaluations. In the past 10 years, our geriatric oncology team has grown exponentially and changed its characteristics in order to adjust them to the hospital demands, raising awareness among the oncology teams about the benefit of using geriatric assessment and promoting multidisciplinary discussions.

A Chicken Tapasin ortholog can chaperone empty HLA-B∗37:01 molecules independent of other peptide-loading components

Human Tapasin (hTapasin) is the main chaperone of MHC-I molecules, enabling peptide loading and antigen repertoire optimization across HLA allotypes. However, it is restricted to the endoplasmic reticulum (ER) lumen as part of the protein loading complex (PLC), and therefore is highly unstable when expressed in recombinant form. Additional stabilizing co-factors such as ERp57 are required to catalyze peptide exchange invitro, limiting uses for the generation of pMHC-I molecules of desired antigen specificities. Here, we show that the chicken Tapasin (chTapasin) ortholog can be expressed recombinantly at high yields in a stable form, independent of co-chaperones. chTapasin can bind the human HLA-B∗37:01 with low micromolar-range affinity to form a stable tertiary complex. Biophysical characterization by methyl-based NMR methods reveals that chTapasin recognizes a conserved β2m epitope on HLA-B∗37:01, consistent with previously solved X-ray structures of hTapasin. Finally, we provide evidence that the B∗37:01/chTapasin complex is peptide-receptive and can be dissociated upon binding of high-affinity peptides. Our results highlight the use of chTapasin as a stable scaffold for protein engineering applications aiming to expand the ligand exchange function on human MHC-I and MHC-like molecules.

Partial Oxidation Synthesis of Prussian Blue Analogues for Thermo-Rechargeable Battery

A thermo-rechargeable battery or tertiary battery converts thermal energy into electric energy via an electrochemical Seebeck coefficient. The manufacturing of the tertiary batteries requires a pre-oxidation step to align and optimize the cathode and anode potentials. The pre-oxidation step, which is not part of the secondary battery manufacturing process, makes the manufacturing of tertiary batteries complex and costly. To omit the pre-oxidation step, we used partially oxidized Prussian blue analogs, i.e., NaxCo[Fe(CN)6]yzH2O (Co-PBA) and NaxNi[Fe(CN)6]yzH2O (Ni-PBA), as cathode and anode materials. The modified tertiary battery without the pre-oxidation step shows good thermal cyclability between 10 ∘C and 50 ∘C without detectable deterioration of the thermal voltage (Vcell) and discharge capacity (Qcell).

Chemical functionalization of drinking water treatment residuals with calcium silicate hydrate to treat metal-enriched waters

Drinking water treatment residuals (DWTRs) provide an opportunity to further embrace circular economy in the urban water cycle. DWTRs surface properties can be improved by chemical functionalization to enhance the pollutant removal performance. Fe/Al-DWTRs were functionalized with nanostructured calcium silicate (nanoCSH) to remove Cu(II) and As(V) from rivers, simulating an accidental acid spill. Model raw DWTRs were generated using raw water. DWTRs were physicochemically characterized by a multi-technique approach (SEM-EDS, FT-IR, BET, XRD). Sorption experiments were performed using Cu(II) and As(V) by varying the initial pH and DWTRs doses. Compared with raw DWTRs, NanoCSH_DWTRs demonstrated a higher removal efficiency in acidic settings, faster removal rates, and higher effectiveness at lower dosages. Kinetic and equilibrium sorption experiments were performed. Experiments simulating accidental Cu and As pollution from acid drainage revealed that NanoCSH_DWTRs had a higher collective removal of As(V) when Cu(II) was present, most likely due to the synergistic relationship formed by the tertiary metal-surface complexes. An application approach was implemented using theoretical case studies. NanoCSH_DWTRs reduced the dose required to treat metal(loid)-enriched water compared to raw DWTRs. NanoCSH_DWTRs would provide an alternative as a first line of defense against the accidental release of acidic drainage.

SARS-CoV-2 SUD2 and Nsp5 Conspire to Boost Apoptosis of Respiratory Epithelial Cells via an Augmented Interaction with the G-Quadruplex of BclII.

The molecular mechanisms underlying how SUD2 recruits other proteins of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to exert its G-quadruplex (G4)-dependent pathogenic function is unknown. Herein, Nsp5 was singled out as a binding partner of the SUD2-N+M domains (SUD2core) with high affinity, through the surface located crossing these two domains. Biochemical and fluorescent assays demonstrated that this complex also formed in the nucleus of living host cells. Moreover, the SUD2core-Nsp5 complex displayed significantly enhanced selective binding affinity for the G4 structure in the BclII promoter than did SUD2core alone. This increased stability exhibited by the tertiary complex was rationalized by AlphaFold2 and molecular dynamics analysis. In line with these molecular interactions, downregulation of BclII and subsequent augmented apoptosis of respiratory cells were both observed. These results provide novel information and a new avenue to explore therapeutic strategies targeting SARS-CoV-2. IMPORTANCE SUD2, a unique protein domain closely related to the pathogenesis of SARS-CoV-2, has been reported to bind with the G-quadruplex (G4), a special noncanonical DNA structure endowed with important functions in regulating gene expression. However, the interacting partner of SUD2, among other SARS-CoV-2 Nsps, and the resulting functional consequences remain unknown. Here, a stable complex formed between SUD2 and Nsp5 was fully characterized both in vitro and in host cells. Moreover, this complex had a significantly enhanced binding affinity specifically targeting the Bcl2G4 in the promoter region of the antiapoptotic gene BclII, compared with SUD2 alone. In respiratory epithelial cells, the SUD2-Nsp5 complex promoted BclII-mediated apoptosis in a G4-dependent manner. These results reveal fresh information about matched multicomponent interactions, which can be parlayed to develop new therapeutics for future relevant viral disease.

Novel Regioselective Synthesis of 1,3,4,5-Tetrasubstituted Pyrazoles and Biochemical Valuation on F1FO-ATPase and Mitochondrial Permeability Transition Pore Formation.

An efficient, eco-compatible, and very cheap method for the construction of fully substituted pyrazoles (Pzs) via eliminative nitrilimine-alkene 1,3-dipolar cycloaddition (ENAC) reaction was developed in excellent yield and high regioselectivity. Enaminones and nitrilimines generated in situ were selected as dipolarophiles and dipoles, respectively. A deep screening of the employed base, solvent, and temperature was carried out to optimize reaction conditions. Recycling tests of ionic liquid were performed, furnishing efficient performance until six cycles. Finally, a plausible mechanism of cycloaddition was proposed. Then, the effect of three different structures of Pzs was evaluated on the F1FO-ATPase activity and mitochondrial permeability transition pore (mPTP) opening. The Pz derivatives' titration curves of 6a, 6h, and 6o on the F1FO-ATPase showed a reduced activity of 86%, 35%, and 31%, respectively. Enzyme inhibition analysis depicted an uncompetitive mechanism with the typical formation of the tertiary complex enzyme-substrate-inhibitor (ESI). The dissociation constant of the ESI complex (Ki') in the presence of the 6a had a lower order of magnitude than other Pzs. The pyrazole core might set the specific mechanism of inhibition with the F1FO-ATPase, whereas specific functional groups of Pzs might modulate the binding affinity. The mPTP opening decreased in Pz-treated mitochondria and the Pzs' inhibitory effect on the mPTP was concentration-dependent with 6a and 6o. Indeed, the mPTP was more efficiently blocked with 0.1 mM 6a than with 1 mM 6a. On the contrary, 1 mM 6o had stronger desensitization of mPTP formation than 0.1 mM 6o. The F1FO-ATPase is a target of Pzs blocking mPTP formation.

Von Willebrand factor: from figurant to main character in the scene of inflammation

von Willebrand factor: from figurant to main character in the scene of inflammation

Physical modification on gelation of fish gelatin by incorporating Nicandra physalodes (Linn.) Gaertn. pectin: Effect of monovalent and divalent cation ions

Fish gelatin (FG) is more appreciated by religious people than mammalian gelatin. However, the relatively poor gelling capacity of FG limits its applicability in the food industry. In this study, Nicandra physalodes (Linn.) Gaertn. pectin (NPGP) was incorporated into FG to modify its gelling capacity, and the effect of monovalent (Na+) and divalent cations (Ca2+) on the gelation process of FG/NPGP mixtures was investigated. At a fixed concentration of FG (5.0 %, w/v) and NPGP (0.2 %, w/v), mixing the two polymers at natural pH condition (pH ≈ 6.0) led to significant intermolecular electrostatic association, which increased the gel hardness by producing an FG-dominant network augmented by NPGP molecules. When Na+ and Ca2+ were introduced, the electrostatic association was greatly decreased, which further weakened the gels. At low Ca2+ concentration (5 mM), however, FG, NPGP and Ca2+ formed tertiary complexes, which provided additional crosslinks and thus increased the gel strength.

Structures of a mobile intron retroelement poised to attack its structured DNA target.

Group II introns are ribozymes that catalyze their self-excision and function as retroelements that invade DNA. As retrotransposons, group II introns form ribonucleoprotein (RNP) complexes that roam the genome, integrating by reversal of forward splicing. Here we show that retrotransposition is achieved by a tertiary complex between a structurally elaborate ribozyme, its protein mobility factor, and a structured DNA substrate. We solved cryo-electron microscopy structures of an intact group IIC intron-maturase retroelement that was poised for integration into a DNA stem-loop motif. By visualizing the RNP before and after DNA targeting, we show that it is primed for attack and fits perfectly with its DNA target. This study reveals design principles of a prototypical retroelement and reinforces the hypothesis that group II introns are ancient elements of genetic diversification.

33 Evaluation of a Secure Messaging System for Children with Medical Complexity

Abstract Background The Connecting2gether (C2) platform is a secure online information-sharing tool that aims to improve care for children with medical complexity (CMC) and their families. A key feature of C2 is secure messaging which enables parents to communicate with their child’s care team members (CTMs) in a timely manner. Objectives (1) Evaluate the use of a secure messaging system, (2) Examine and compare the content of messages to email and phone calls, and (3) Explore parent and CTMs’ perceptions and experience using secure messaging as a method of communication. Design/Methods This study is a sub-study of a larger feasibility evaluation of the C2 platform. Parents of CMC were recruited from a tertiary level complex care program to use the C2 platform for 6 months. Parents could invite CTMs involved in their child’s care to register on the platform. Secure messages were extracted from C2 usage reports, and phone and email documentation from the electronic medical record. Quantitative data from C2 usage reports were analyzed using descriptive statistics. Messaging content codes were iteratively developed through review of the C2 messages. Semi-structured interviews were completed with parents and CTMs. Communication and interview data were analyzed using thematic analysis. Results 36 parents and 43 care team members, including HCPs and family members, registered on the C2 platform. Participants sent a total of 1853 messages on C2 with parents and nurse practitioners sending a mean of 33.1 and 87.4 messages, respectively. 85.5% of all C2 messages were responded to within 24 hours. Email and phone calls focused primarily on clinical concerns and medications, whereas C2 messaging focused more on education, proactive check-ins, and non-medical aspects of the child’s life (Figure 1). Four themes emerged from the participant interviews related to C2 messaging: Connection to Care Team, Efficient Communication, Clinical Uses of Secure Messaging, and Barriers to Use (Figure 2). Conclusion Overall, our study provides valuable insight into the benefits of secure messaging in the care of CMC. Secure messaging provided the opportunity for continued patient education, proactive check-ins from HCPs, and casual conversations about family and child life, which contributed to parents feeling an improved sense of connection with their child’s health care team. Secure messaging can be a beneficial additional communication method to improve communication between parents and their care team, reduce the associated burden of care coordination, and ultimately, improve the experience of care delivery.