Multiple Functional Sites Research Articles

Nonpolar microporous Metal-Organic framework decorated with multiple functional sites for efficient Ethane/Ethylene separation

Efficiently achieving one-step adsorption separation of ethylene (C2H4) from ethane (C2H6) is a highly sought-after yet challenging task in the petrochemical industry. This underscores the need for enhanced standards in designing functional groups to formulate physisorbent materials with exceptional C2H6 trapping capacity, high C2H6/C2H4 selectivity, and material stability. In this study, we introduced a novel C2H6-selective microporous MOF (Zn-IPA-F-dmtrz), characterized by a nonpolar pore surface decorated with distinct advantageous O/N/F binding sites, creating a specialized nano-trap for C2H6, thereby enabling high-purity C2H4 production from C2H6/C2H4 mixtures. The synthesized Zn-IPA-F-dmtrz exhibited a remarkable C2H6 capacity of 4.6 mmol/g, coupled with an excellent C2H6/C2H4 selectivity of 2.3 at 298 K and 1 bar, outperforming the performance of many top-ranking adsorbents reported in recent years. Molecular simulation further demonstrated multiple synergistic interactions between this framework and C2H6. Moreover, breakthrough experiments confirmed the good stability of Zn-IPA-F-dmtrz, indicating its effectiveness in separating C2H6/C2H4 mixtures even under high-humidity conditions. This work provides valuable insights into how purposeful functionalization of nonpolar pore surfaces contributes to the construction of MOF materials tailored for highly efficient C2H6/C2H4 separation applications.

Nanocounter on cell membrane: In-situ quantification of membrane-bound enzymes with high simplicity and sensitivity via the assembly of branched peptides

The quantitative analysis of membrane-bound enzymes (MBEs) is still challenged by complicated process, expensive equipment, and/or limited sensitivity. Herein, a highly sensitive yet user-friendly colorimetric method is proposed for the in-situ quantification of MBEs via the reasonable assembly of branched peptides. Taking alkaline phosphatase (ALP) as an example, the designed assembly of branched peptides can respond to the membrane-bound enzyme and undergo a spontaneous transformation to load signal reporters, giving rise to a colorimetric signal. Therefore, this method allows for simple in-situ measurements of MBEs without the need for complicated protein isolation or labeling processes or sophisticated equipment. Significantly, the exploitation of branched peptides with multiple functional sites enables both multivalent recognition of targets and large-scale loading of signal reporters, achieving ultra-high sensitivity. As a result, as few as 34 pg of ALP on HepG2 cell membrane can be measured directly in cell suspension in an add-to-respond manner. Furthermore, the successful differentiation of cancer cells with ALP overexpression depicts the potential application of this method. By adjusting the target-responsive peptide sequences, this work can be generally expanded for versatile MBE analysis and other related biomedical research.

Adsorption Behavior of a Ternary Covalent Organic Polymer Anchored with SO3H for Ciprofloxacin.

Owing to the poor treatment efficiency of wastewater containing fluoroquinolones (FQs), effective removal of such pollutants has become a significant issue in waste management. In this study, a ternary covalent organic polymer anchored with SO3H (COP-SO3H) was designed using the Schiff reaction and a multicomponent solvent thermal method. The synthesized COP-SO3H polymer possesses multiple functional binding sites, including amide groups, sulfonic groups, and aromatic frameworks, enabling it to effectively adsorb ciprofloxacin (which belongs to FQs) through mechanisms such as pore-filling effects, electrostatic interactions, hydrogen bonding, π-π electron donor-acceptor (EDA) interactions, and hydrophilic-lipophilic balance. COP-SO3H demonstrated outstanding adsorption performance for ciprofloxacin, exhibiting a high adsorption capacity, broad pH stability, strong resistance to ionic interference, and good regenerability. Moreover, it displayed preferential selectivity toward fluoroquinolone antibiotics. The present study not only investigates the intricate structural and functional design of COP-SO3H materials but also presents potential applications for the efficient adsorption of specific antibiotics.

Molecular cloning and tissue distribution of glucokinase and glucose-6-phosphatase catalytic subunit paralogs in largemouth bass Micropterus salmoides: Regulation by dietary starch levels and a glucose load

The dysregulation of glucose-G6P (glucose-6-phosphate) interconversion is thought to be one of the main reasons for the low glucose disposal of carnivorous fish, but is not yet well understood in largemouth bass Micropterus salmoides (LMB). In this study, the full length cDNA sequences of genes encoding glucokinase (Gck, catalyzing glucose phosphorylation) and glucose-6-phosphatase catalytic subunit (G6pc, catalyzing glucose dephosphorylation) were cloned by the RACE method from the liver of LMB. Subsequently, the distribution of g6pc and gck as well as their transcriptional regulation by dietary starch levels and a glucose load were investigated. Only one gck gene was identified, while the tandem duplication of g6pca.1 gene was named as g6pca.2 in LMB. The full cDNA sequences of g6pca.1, g6pca.2 and gck in LMB were 1585, 1813 and 2115 bp in length, encoding 478, 352 and 359 amino acids, respectively. Gck was predicted to contain two hexokinase domains, an ATP-binding domain and multiple functional sites, while G6pca.1 and G6pca.2 contained nine transmembrane helices, a PAP2 (type-2 phosphatidic acid phosphatase) domain and multiple functional amino acid sites. Both g6pca.1 and g6pca.2 were predominantly distributed in the liver and to some extent in the intraperitoneal fat, intestine and pyloric caeca, while gck was mainly transcribed in the liver and to some extent in the heart, intestine and brain. Both feeding a high starch diet and a glucose load stimulated the mRNA expression of gck in the liver of LMB. An increase of dietary starch from 9% to 14% down-regulated the transcription of g6pca.1 in the liver of LMB. However, both the mRNA levels of hepatic g6pca.1 and g6pca.2 were sharply up-regulated in LMB during 1–3 h after a glucose load. Overall, the results of this study suggested that the functions of G6pc (G6pca.1 and G6pca.2) and Gck in LMB were highly conserved in evolution. Though hepatic glucose-G6P interconversion was well regulated at the transcript level in LMB fed high starch diets, a futile cycle between glucose and G6P was induced in the liver after a glucose load.

Solution combusted ultrathin Co3O4/CoO heterophase electrocatalyst for solar‐energy driven bifunctional water electrolysis

AbstractPotential low‐cost solution combustion synthesis of cobalt oxide (SCSCO: Co3O4/CoO) by using sugar as a fuel for H2 and O2 generation. Co3O4/CoO heterophase provided multiple functional sites and abundant interfaces between the components owing to synergistic effect. The sufficient adsorption sites in SCSCO6 favoured the formation of reactive intermediates which leads to extraordinary OER and HER process. The SCSCO6 exhibits η of 271 mV (102 mV dec−1) for OER and 174 mV (73 mV dec−1) for HER to achieve 10 mA cm−2 (without iR correction). TOF of SCSCO6 (OER: 0.0624 s−1/IrO2‐ 0.0185 s−1; HER: 0.0282 s−1/Pt ‐ 0.0843 s−1) was found to be higher than IrO2 and near to Pt, respectively. The SCSCO6 displays durability of 130 h with potential loss of 3.2 % (OER) and 3.0 % (HER). The disordered oxidation states and high surface area of SCSCO6 (BET ‐ 99 m2 g−1: ECSA ‐ 151.27 m2/g) facilitates the bifunctional activity. The fabricated water electrolyzer consist of SCSCO6//SCSCO6 affords 10 mA cm−2 @1.64 V and exhibits high stability (>130 h: 4.1 % potential loss). The solar‐to‐hydrogen electrolyser (SCSCO6//SCSCO6) afforded non‐stop evolution of H2 and O2 @1.63 V which can be recommended for low‐cost, large‐scale hydrogen production.

BIOSORPTIVE REMOVAL OF COPPER(II) FROM WASTEWATER BY HYBRID BIOSORBENT: ADSORPTION KINETICS AND MECHANISMS

Combining two well-known biosorbents, Pleurotus sajor caju and almond shell, with a newly created straightforward immobilization approach led to the creation of a unique hybrid biosorbent. The hybrid biosorbent’s capacity to eliminate Cu(II) from aqueous solution was assessed. The immobilized hybrid biosorbent exhibited the greatest values for Cu(II) adsorption at a pH about 5.0. The ideal contact period and metal concentration were 240 minutes and 10 mg/L, respectively. The pseudo-second order kinetics and Langmuir adsorption isotherms models were used to explain the biosorption kinetics and equilibria. The presence of multiple functional groups and active sites may be seen in the hybrid biosorbent’s FTIR spectra. Prior to biosorption, the hybrid biosorbent’s SEM micrograph showed that its surface was uneven, rough, and porous. A successful and potentially alluring method for dealing with heavy metal-polluted aqueous solutions is the hybrid biosorbent technique, which is quite inexpensive and effectively removes a lot of Cu(II).

Computer modelling of trace SO2 and NO2 removal from flue gases by utilizing Zn(ii) MOF catalysts

Theoretical investigations on the adsorption and chemical conversion of SO2 and NO2 gases by using porous Zn(ii)-MOFs with multiple functional sites.

Application of transition metal boride nanosheet as sulfur host in high loading Li-S batteries

Two-dimensional (2D) metal boride material (MBene) has aroused concern recently. However, the research and application exploration for MBene materials with more exposure sites are seriously restricted due to lack of suitable preparation methods. Herein, a kind of composites of monolayer MBene nanosheets and carbon nanotube (mono-MBene/CNT) is prepared through ice template method for the first time and applicated as a novel cathode host in high-loading lithium-sulfur (Li-S) batteries. Benefiting from multifunctional advantages of mono-MBene/CNT cathode including anchoring lithium polysulfides (LiPS), multiple functional sites and fast lithium-ion transport, the cells with S@mono-MBene/CNT cathode exhibit superior long-term cycling performance over 1000 cycles. Most notably, even if the sulfur loading is up to 15.28 mg cm−2, the cells with S@mono-MBene/CNT cathode deliver an initial area capacity of 12.73 mAh cm−2 and the capacity can also maintain at 11.07 mAh cm−2 after 120 cycles (86.96 % capacity retention) with current density of 21.80 mA cm−2, which is approximately 3 times higher than the capacity of commercial lithium-ion batteries. This work not only provides a guiding role in preparing monolayer MBene material, but also exhibits the application prospect for MBene material in the fields of energy storage.

Metal‐Organic Framework with High Densities of Open Metal Sites for Efficient Separation of Propylene from Propane

AbstractThe separation of propylene/propane (C3H6/C3H8) is a critical yet challenging process owing to their similar physical properties and molecular size. So it's urgent to explore efficient porous adsorbents to take place of the energy‐intensive consumption and high cost of traditional cryogenic distillation technologies. Here, we report a mixed metal‐organic framework (M'MOF), [Fe(pyz)Pt(CN)4] (FePt‐M'MOF, pyz=pyrazine) for selective adsorptive separation of C3H6/C3H8at room temperature, which has multiple functional sites and optimized pore channels of about 4.0 Å. This MOF has an excellent separation performance with C3H6uptake of 47.4 cm3/g and a high C3H6/C3H8selectivity of 4.7 under ambient conditions. The separation performance of propylene in this material is driven by π‐π stacking and multiple intermolecular interactions between propylene molecules and the binding sites of FePt‐M'MOF. This material can be prepared at room temperature and is stable in water, providing potential applications for industrial C3H6/C3H8separation.

Predicting the optimal chemical composition of functionalized carbon catalysts towards oxidative dehydrogenation of ethanol to acetaldehyde

A significant challenge in developing ideal carbon-based catalysts for oxidative dehydrogenation of ethanol to acetaldehyde is to correlate the catalytic efficiencies with the multiple functional sites on the catalysts qualitatively and quantitatively. By making a series of two-dimensional carbon catalysts with varied oxygen and nitrogen functional sites and testing the catalytic performances, we show the roles the specific functional groups played in the catalytic conversion process. Moreover, a map that includes the quantitative ratio of different active sites and the acetaldehyde yield is provided, which can be used to predict the ideal structure of a potential catalyst. The resulted catalyst showed the ethanol conversion rate of 54 %, the acetaldehyde selectivity of 84 %, and the attractive yield of acetaldehyde up to 45 %, surpassing the performances of the majority of reported carbon-catalysts tested under a similar condition. Our prediction reveals that the ideal balance of surface pyridinic-N/ graphitic-N in a carbon catalyst should be in the range of ~0.7–1.0 while the C-O/ CO is ~0.7–0.8, which could be very useful to the researches in this field. The combination of experiments, theoretical simulations, and especially the quantitative prediction deepens the understanding of the catalysts and the catalytic reactions, which is expected to be extended to the study of other catalytic processes.

A new metallic composite cathode originated from hyperbranched polymer coated MOF for High-performance Lithium-Sulfur batteries

To improve the polysulfides redox conversion and mitigate the shuttle effect for lithium-sulfur (Li-S) batteries, a hyperbranched polymer coated MOF-derived zirconium nitrogen oxides and N-doping carbon composites (Zr2N2O/NC-6) are designed and prepared by pyrolytic method. Thanks to some advantages of this type of new composites including fast lithium-ion transport, lithium polysulfides (LiPSs) anchoring and multiple functional sites, the cells with S/Zr2N2O/NC-6 cathode exhibit good cycle stability (the capacity retention is 81.8% at 1C after 300 cycles) and rate capability (566.8 mAh g−1 at 5C). More importantly, even if the sulfur loading is up to 8.16 mg cm−2 and low electrolyte/sulfur (E/S) ratio (7.79 µL mg−1), the cells with S/Zr2N2O/NC-6 cathode deliver an initial area capacity of 7.2 mAh cm−2 and the capacity also can maintain at 5.34 mAh cm−2 after 80 cycles at 0.2C, which are much better than the commercial lithium-ion batteries. This work exhibits a MOF-derived novel material Zr2N2O/NC used as the sulfur host for the first time, which can have a guiding role in designing multifunctional materials with adsorption, ion transport and catalytic features for the high-performance lithium sulfur batteries with application potential.

Polyelectrolyte Encapsulation and Confinement within Protein Cage-Inspired Nanocompartments.

Protein cages are nanocompartments with a well-defined structure and monodisperse size. They are composed of several individual subunits and can be categorized as viral and non-viral protein cages. Native viral cages often exhibit a cationic interior, which binds the anionic nucleic acid genome through electrostatic interactions leading to efficient encapsulation. Non-viral cages can carry various cargo, ranging from small molecules to inorganic nanoparticles. Both cage types can be functionalized at targeted locations through genetic engineering or chemical modification to entrap materials through interactions that are inaccessible to wild-type cages. Moreover, the limited number of constitutional subunits ease the modification efforts, because a single modification on the subunit can lead to multiple functional sites on the cage surface. Increasing efforts have also been dedicated to the assembly of protein cage-mimicking structures or templated protein coatings. This review focuses on native and modified protein cages that have been used to encapsulate and package polyelectrolyte cargos and on the electrostatic interactions that are the driving force for the assembly of such structures. Selective encapsulation can protect the payload from the surroundings, shield the potential toxicity or even enhance the intended performance of the payload, which is appealing in drug or gene delivery and imaging.

Characterization of Non-Small-Cell Lung Cancers With MET Exon 14 Skipping Alterations Detected in Tissue or Liquid: Clinicogenomics and Real-World Treatment Patterns.

PURPOSEMET exon 14 (METex14) skipping alterations are oncogenic drivers in non–small-cell lung cancer (NSCLC). We present a comprehensive overview of METex14 samples from 1,592 patients with NSCLC, associated clinicogenomic characteristics, potential mechanisms of acquired resistance, treatment patterns, and outcomes to MET inhibitors.METHODSHybrid capture–based comprehensive genomic profiling (CGP) was performed on samples from 69,219 patients with NSCLC. For treatment patterns and outcomes analysis, patients with advanced METex14-altered NSCLC were selected from the Flatiron Health-Foundation Medicine clinicogenomic database, a nationwide deidentified electronic health record–derived database linked to Foundation Medicine CGP for patients treated between January 2011 and March 2020.RESULTSA total of 1,592 patients with NSCLC (2.3%) were identified with 1,599 METex14 alterations spanning multiple functional sites (1,458 of 60,244 tissue samples and 134 of 8,975 liquid samples). Low tumor mutational burden and high programmed death ligand 1 expression were enriched in METex14-altered samples. MDM2, CDK4, and MET coamplifications and TP53 mutations were present in 34%, 19%, 11%, and 42% of tissue samples, respectively. Comparing tissue and liquid cohorts, coalteration frequency and acquired resistance mechanisms, including multiple MET mutations, EGFR, ERBB2, KRAS, and PI3K pathway alterations, were generally similar. Positive percent agreement with the tissue was 100% for METex14 pairs collected within 1 year (n = 7). Treatment patterns showed increasing adoption of MET inhibitors in METex14-altered NSCLC after receipt of CGP results; the real-world response rate to MET inhibitors was 45%, and time to treatment discontinuation was 4.4 months.CONCLUSIONDiverse METex14 alterations were present in 2%-3% of NSCLC cases. Tissue and liquid comparisons showed high concordance and similar coalteration profiles. Characterizing common co-occurring alterations and immunotherapy biomarkers, including those present before or acquired after treatment, may be critical for predicting responses to MET inhibitors and informing rational combination strategies.

Surface coupling of oligo-functionalized dendrimers to detect DNA mutations after blocked isothermal amplification

This study presents a useful strategy for the bioconjugation of probes for developing high-performance versatile chips applied to fast-response, low-cost DNA biosensing. We herein demonstrate that the high-density immobilization of dendrimer-oligonucleotide hybrids promotes the reliable sensitive sensing of single-nucleotide variants despite their low concentration.Carboxyl-terminated poly(amidoamine) dendrimers directly coupled to amine-derivatized oligonucleotides were anchored to the activated surfaces of thermoplastics (polycarbonate and cycloolefin polymer). Surface characterization techniques and hybridization assays reported that the multiple functional sites of the oligo-functionalized dendrimer facilitated the efficient immobilization of probes and the sensitive capture of DNA targets (5 pM detection limit). Array performance was better than that of the surfaces functionalized with linear crosslinkers, such as vinyltriethoxysilane or 3-(triethoxysilyl)propyl isocyanate, as well films with unconjugated dendrimer molecules.Based on oligo-dendrimers hybrids, disposable DNA-based biosensing platforms were developed for point-of-care diagnostics. A selective high-sensitive hybridization assay was performed that included amplification products of blocked PCR and recombinase polymerase amplification (RPA) as an isothermal reaction. The chip results indicated that the single-nucleotide mutant variant of the BRAF oncogene was correctly discriminated in colorectal tissues from cancer patients.

Zirconia and Phosphotungstic Acid Supported on TS-1 as An Active Catalyst for One-Pot Selective Conversion of Furfuryl Alcohol to γ-Valerolactone

Gamma-valerolactone (GVL) has been identified as a sustainable high-value platform molecular for the production of fuels and carbon-based chemicals. In this work, a novel bifunctional Zr-P/TS-1 catalyst with Brønsted and Lewis acidic sites that enables an efficient one-pot conversion of furfuryl alcohol (FAL) into GVL has been developed by loading ZrO2 and phosphotungstic acid on TS-1. A GVL selectivity of 85.2% at FAL conversion of 100% could be achieved at 170 °C in 24 h over 30Zr-10P/TS-1 using 2-propanol as the hydrogen donor and solvent. Through XRD, TG-DTG, NH3-TPD, SEM, EDS and XPS analysis, the synergistic effect of multiple functional sites is responsible for the good catalytic activity of the catalyst. Based on products distribution, reasonable reaction pathways and mechanisms have been proposed. Brønstedacidic sites of phosphotungstic acid promotes the conversion of furfuryl alcohol to isopropyl levulinate via intermediate isopropyl furfuryl ether in the reaction, and the Lewis acidic sites of ZrO2 effectively catalyzes the transfer hydrogenation of isopropyl levulinate to GVL. Moreover, the 30Zr-10P/TS-1 catalyst was reused for four cycles and exhibited good stability.

One-pot conversion of furfural to gamma-valerolactone in the presence of multifunctional zirconium alizarin red S hybrid

A multifunctional Zr-containing catalyst (FM-Zr-ARS) was successfully synthesized by a modulated hydrothermal synthesis route. Systematic characterization results supported the presence of robust porous inorganic-organic frameworks stabilized by the strong coordination interaction of Zr4+ with oxygen-rich functional groups in Alizarin red S (ARS). Moreover, the -O-Zr-O- network in the FM-Zr-ARS structure formed a rich content of acid-base sites. In addition, the inherent sulfonic groups in ARS made the FM-Zr-ARS hybrids possess Brønsted acid sites. Therefore, under the synergistic catalysis of the multiple functional sites, FM-Zr-ARS showed remarkably high catalytic activity for γ-valerolactone (GVL) production from levulinate esters and furfural. Finally, 72.4 % and 97.7 % yields of GVL were obtained in the conversion of furfural and ethyl levulinate, respectively, after 8 h of reaction at 433 K. On the basis of the role of different functional sites, a plausible catalytic mechanism was presented for the conversion of biomass-derived furfural to GVL.

Rational Design of a ZnII MOF with Multiple Functional Sites for Highly Efficient Fixation of CO2 under Mild Conditions: Combined Experimental and Theoretical Investigation.

The development of efficient heterogeneous catalysts suitable for carbon capture and utilization (CCU) under mild conditions is a promising step towards mitigating the growing concentration of CO2 in the atmosphere. Herein, we report the construction of a hydrogen-bonded 3D framework, {[Zn(hfipbba)(MA)]⋅3 DMF}n (hfipbba=4,4'-(hexaflouroisopropylene)bis(benzoic acid)) (HbMOF1) utilizing ZnII center, a partially fluorinated, long-chain dicarboxylate ligand (hfipbba), and an amine-rich melamine (MA) co-ligand. Interestingly, the framework possesses two types of 1D channels decorated with CO2 -philic (-NH2 and -CF3 ) groups that promote the highly selective CO2 adsorption by the framework, which was supported by computational simulations. Further, the synergistic involvement of both Lewis acidic and basic sites exposed in the confined 1D channels along with high thermal and chemical stability rendered HbMOF1 a good heterogeneous catalyst for the highly efficient fixation of CO2 in a reaction with terminal/internal epoxides at mild conditions (RT and 1 bar CO2 ). Moreover, in-depth theoretical studies were carried out using periodic DFT to obtain the relative energies for each stage involved in the catalytic reaction and an insight mechanistic details of the reaction is presented. Overall, this work represents a rare demonstration of rational design of a porous ZnII MOF incorporating multiple functional sites suitable for highly efficient fixation of CO2 with terminal/internal epoxides at mild conditions supported by comprehensive theoretical studies.

Hyaluronan-based Multifunctional Nano-carriers for Combination Cancer Therapy.

Hyaluronan (HA) is a natural linear polysaccharide that has excellent hydrophilicity, biocompatibility, biodegradability, and low immunogenicity, making it one of the most attractive biopolymers used for biomedical researches and applications. Due to the multiple functional sites on HA and its intrinsic affinity for CD44, a receptor highly expressed on various cancer cells, HA has been widely engineered to construct different drug-loading nanoparticles (NPs) for CD44-targeted anti-tumor therapy. When a cocktail of drugs is co-loaded in HA NP, a multifunctional nano-carriers could be obtained, which features as a highly effective and self-targeting strategy to combat cancers with CD44 overexpression. The HA-based multidrug nano-carriers can be a combination of different drugs, various therapeutic modalities, or the integration of therapy and diagnostics (theranostics). Up to now, there are many types of HA-based multidrug nano-carriers constructed by different formulation strategies, including drug co-conjugates, micelles, nano-gels and hybrid NP of HA and so on. This multidrug nano-carrier takes the full advantages of HA as an NP matrix, drug carriers and targeting ligand, representing a simplified and biocompatible platform to realize the targeted and synergistic combination therapy against the cancers. In this review, recent progress of HA-based multidrug nano-carriers for combination cancer therapy is summarized and the potential challenges for translational applications have been discussed.

Characterization of 1,387 NSCLCs with MET exon 14 (METex14) skipping alterations (SA) and potential acquired resistance (AR) mechanisms.

9511 Background: METex14 SA are oncogenic drivers in NSCLC. Due to the numerous sites around ex14 that bind the spliceosome complex, many variations can result in deleterious alterations (alts). We present a comprehensive overview of these ex14 SA across 1,387 NSCLCs and characterized potential AR mechanisms. Methods: Hybrid-capture based comprehensive genomic profiling (CGP) was performed on samples from 60,495 NSCLC patients (pts). A scoring system was applied leveraging our large database of samples with METex14 SA to optimize accurate reporting of these variants. Paired samples were collected ≥ 60 days apart (median 462). Results: 1,393 METex14 SA were identified in samples (1,278 tissue, 109 circulating tumor DNA (ctDNA)) from 1,387 NSCLC pts (2.3%) spanning multiple functional sites: donor (42%), acceptor (4.7%), poly-pyrimidine tract (15%), acceptor and polypyrimidine tract (13%), D1010 (23%), Y1003 (2.1%), and whole exon deletions (0.3%). 6 samples (5 tissue, 1 ctDNA) harbored 2 METex14 SA, each including a mutation (mut) at the donor or acceptor site. MDM2 and CDK4 amplifications (amps) co-occurred in 32% and 19% of METex14 samples, respectively, but were more common with polypyrimidine tract (37% and 23%) vs donor site (32%, p = 0.07 and 18%, p = 0.07) alts. MET co-amp was present in 12% of cases and frequency did not significantly differ by functional site. 66 (4.8%) cases (57 tissue, 9 ctDNA) had known NSCLC co-drivers, including KRAS (68%) and EGFR (14%) mut, a subset of which may represent AR. Paired samples with a METex14 SA in the 1st sample were available for 36 pts. The METex14 SA was detected in the 2nd sample for 32 pts, excluding 3 with low ctDNA. 22/36 (61%) had reportable acquired alts detected including 9 with ≥1 acquired MET muts [D1228X (4), Y1230X (3), Y1003F (1), D1228A/E/H + L1195V (1)] and 3 with acquired MET amp. Other acquired alts included ERBB2 amp and mut (1 each), EGFR ex19ins (1), KRAS amp (1), PIK3CA mut (1), AKT2 amp (1) and others with unknown functional significance. Potential AR alts were present with primary METex14 SA spanning all functional sites. Conclusions: In a dataset of > 60,000 advanced NSCLCs, METex14 SA were present in 2.3% of cases, and represented 6 major subtypes. Among paired cases, potential AR mechanisms included secondary MET alts (33%), and acquired alts in EGFR, ERBB2, KRAS, and PI3K pathways. Acquired alts were independent of the type of METex14 SA. Characterizing common co-occuring may be critical for predicting responses to MET inhibitors and informing rational combination strategies.

Modular repeat protein sculpting using rigid helical junctions

The ability to precisely design large proteins with diverse shapes would enable applications ranging from the design of protein binders that wrap around their target to the positioning of multiple functional sites in specified orientations. We describe a protein backbone design method for generating a wide range of rigid fusions between helix-containing proteins and use it to design 75,000 structurally unique junctions between monomeric and homo-oligomeric de novo designed and ankyrin repeat proteins (RPs). Of the junction designs that were experimentally characterized, 82% have circular dichroism and solution small-angle X-ray scattering profiles consistent with the design models and are stable at 95 °C. Crystal structures of four designed junctions were in close agreement with the design models with rmsds ranging from 0.9 to 1.6 Å. Electron microscopic images of extended tetrameric structures and ∼10-nm-diameter "L" and "V" shapes generated using the junctions are close to the design models, demonstrating the control the rigid junctions provide for protein shape sculpting over multiple nanometer length scales.