Cellular Affinity of Particle-Stabilized Emulsion to Boost Antigen Internalization

The cellular affinity of micro-/nanoparticles is the precondition for cellular recognition, cellular uptake, and activation, which are essential for drug ...

Chinese Academy of Sciences

We report in this work real time characterization of enzyme-coenzyme binding by using surface plasmon resonance (SPR) and dual polarization interferometry (DPI) analyses. Results showed that diaphorase (DP) and lactate dehydrogenases (LDH) had distinct binding selectivity and preference over reduced and oxidized states of coenzyme NAD(H). On the basis of that, DP and LDH were chosen as indicator enzymes to distinguish the specific state of surface-bound NAD(H). The transformation between NADH and NAD(+) during enzyme-catalyzed redox reactions was therefore transduced into variation in interaction signals as indicated via the binding status of the indicator enzymes as detected with both SPR and DPI. This real time molecule-specific detection strategy revealed quick and direct reflection of the state and reactivity of the coenzyme, promising a unique way of precise molecular interaction analysis.

Real time monitoring of on-chip coenzyme regeneration with SPR and DPI.

Driven by the prevalent use of ion exchange chromatography (IEC) for polishing therapeutic proteins, many rules have been formulated to summarize the different dependencies between chromatographic data and various operational parameters of interest based on statically determined interactions. However, the effects of the unfolding of protein structures and conformational stability are not as well understood. This study focuses on how the flexibility of proteins perturbs retention behavior at the molecular scale using microscopic characterization approaches, including hydrogen-deuterium (H/D) exchange detected by NMR and a quartz crystal microbalance (QCM). The results showed that a series of chromatographic retention parameters depended significantly on the adiabatic compressibility and structural flexibility of the protein. That is, softer proteins with higher flexibility tended to have longer retention times and stronger affinities on SP Sepharose adsorbents. Tracing the underlying molecular mechanism using NMR and QCM indicated that an easily unfolded flexible protein with a more compact adsorption layer might contribute to the longer retention time on adsorbents. The use of NMR and QCM provided a previously unreported approach for elucidating the effect of protein structural flexibility on binding in IEC systems. 

Microscopic insight into role of protein flexibility during ion exchange chromatography by nuclear magnetic resonance and quartz crystal microbalance approaches.

Flowers or inflorescences often deploy various signals, including visual, olfactory, and gustatory cues, that can be detected by their pollinators. In many plants, these cues and their functions are poorly understood. Deciphering the interactions between floral cues and pollinators is crucial for analyzing the reproductive success of flowering plants. In this study, we examined the composition of the fetid floral scents produced by several Stemona species, including nine S. tuberosa populations from across China, using dynamic headspace adsorption, gas chromatography, and mass spectrometry techniques. We compared variations in floral phenotype, including floral longevity, nectar rewards, pollinator behavior, and flower length and color among the Stemona species. Of the 54 scent compounds identified, the major compounds include fetid dimethyl disulfide, dimethyl trisulfide, 1-pyrroline, butyric acid, p-cresol, isoamyl alcohol, and indole. We detected striking differentiation in floral scent at both the species and population level, and even within a population of plants with different colored flowers. Floral characteristics related to sapromyophily and deceptive pollination, including flower color mimicking livor mortis and a lack of nectar, were found in five Stemona species, indicating that Stemona is a typical sapromyophilous taxon. Species of this monocot genus might employ evolutionary tactics to exploit saprophilous flies for pollination.

Variation in floral characters, particularly floral scent, in sapromyophilous Stemona species.

 Hook.f. & Thomson (Scrophulariaceae) is a threatened alpine plant with a distribution throughout the Himalayas, also used as an ornamental plant. The name  B.S. Sun ex S.Y. Pao was assigned in 1983 to a plant distributed throughout the Gaoligong Mountains, but the name was later placed in synonymy with  in the . In this study we sequenced the complete chloroplast (cp) genomes of two individuals of  and three individuals of  from across the range. Both molecular and morphological analysis support the revision of . The phylogenetic analysis constructed with the whole cp genomes, the large single-copy regions (LSC), small single-copy regions (SSC), inverted repeat (IR) and the nuclear genes 18S/ITS1/5.8S/ITS2/28S all supported  as a distinct species. Additionally, coalescence-based species delimitation methods (bGMYC, bPTP) using the whole chloroplast datasets also supported  as a distinct species. The results suggest that the  lineage was early diverging among the Asian  species. Overall gene contents were similar and gene arrangements were found to be highly conserved in the two species, however, fixed differences were found between the two species. A total of 474 single nucleotide polymorphisms (SNPs) were identified between the two species. The Principal Coordinate Analysis of the morphological characters resolved two groups and supported  as a distinct species. Discrimination of  and  using morphological characters and the redescription of  are detailed here.

Characterization of the Complete Chloroplast Genomes of  and : Implications for the Taxonomy of  L.

3D structures assembled from multiple components have attracted increasing research interest based on their enriched functionalities and broadened applications. Here, we report a bottom-up strategy to fabricate 3D halos through the co-assembly of FeO and Au nanoparticles (NPs). Typically, FeO NPs assemble into a 3D core (size around 500 nm) with simultaneous growth of Au NPs on the 3D surface during the assembly process. As a general approach, a variety of 3D halos were fabricated from the co-assembly of FeO and Au NPs of different sizes and shapes. To demonstrate the advantages of these 3D halo structures, their catalytic activity to mimic natural enzymes was investigated. Compared with FeO NP building blocks, enhanced catalytic efficiency was achieved by the 3D halos. In addition, the optical behavior of the 3D halos was simulated using a three-dimensional finite-difference time-domain (3D-FDTD) method. As shown in the results, the 3D halos attached to 90 nm Au NPs could absorb more incident light owing to high electric field intensities, making these structures promising for applications in energy harvesting and detection-related fields.

3D halos assembled from FeO/Au NPs with enhanced catalytic and optical properties.

Fast-throughput and cost reduction of current purification platforms are becoming increasing requests during antibody manufacture. The macroporous-matrix absorbents have presented extensive potentiality in improving operational throughput during purification of macromolecule. And meanwhile the peptide ligand has become a promising alternative to recombinant protein ligands for cost reduction of chromatographic purification. Therefore, here we designed a functionalized microspheres resin with both macroporous matrix of polymerized glycidyl methacrylate and ethylene glycol dimethacrylate (PGMA-EDMA) and peptide ligand of hexapeptide (FYEILH). In order to circumvent the steric effect of peptides and amplify the binding sites on macroporous matrix, the peptide ligand was coupled on a liner PGMA polymer brushes grafted on microspheres. Comparing to the conventional agarose-matrix resin and the general peptide-grafted microspheres, the functionalized microspheres presented excellent permeability and high capacity to rapid loading hIgG by maintaining a stable level of dynamic binding capacity at fast flow rate above 110 column volume per hour (cv/h) and very short residence time below 0.5 min. Such functionalized microspheres provide a facile and broadly applicable strategy to develop the attractive candidate for rapid and cost-reduced purification of antibody.

Rapid and high-capacity loading of IgG monoclonal antibodies by polymer brush and peptides functionalized microspheres.

 K. M. Feng ex C. Y. Cheng W. C. Cheng and L. K. Fu (Taxaceae) is a threatened plant species and a typical plant species with extremely small populations (PSESP) with only four individuals found in Gaoligong Mountain. With the aim of providing data for future conservation efforts, we sequenced the whole chloroplast (cp) genome of  The results showed that the plastid genome is 136,404 bp in size. In total, 116 unique genes were annotated, including 83 protein-coding genes, 29 tRNA genes, and 4 rRNA genes. The total GC content was 35.1%. We performed phylogenetic analyses based on 12 cp genomes of Taxaceae, and we determined that the genus  forms a sister group to  and .

The complete chloroplast genome of  (Taxaceae), a plant species with extremely small populations.

Seed dispersal by frugivorous birds is a famous plant-animal interaction. However, we demonstrated that frugivorous birds can disperse seeds of Ligustrum lucidum, and its seed parasite weevils and the parasitic wasps from the weevils in this study. The cryptic tetrad of Ligustrum-disperser-weevil-wasp may be an overlooked phenomenon in seed dispersal syndrome.

Frugivorous birds disperse seeds of Ligustrum lucidum, seed-feeding weevils, and parasitic wasps of weevils via endozoochory.

Mystery revisited: Is nocturnal colored nectar a nonadaptive floral trait?

DNA-templated silver nanoclusters (DNA-AgNCs) are promising fluorescent materials and have been used in cancer diagnosis. Although many different DNA-AgNC applications have been realized, most of them rely on individual DNA-AgNCs or assembled DNA-AgNCs with limited recognition abilities, resulting in low detection sensitivity or off-target effects, in turn, hindering the performance of DNA-AgNCs in cancer cell recognition. As a solution, we assembled DNA-AgNCs by a multibranched linear (MBL) DNA structure formed through a trigger-initiated hybridization chain reaction (HCR) regarding the natural compatibility of DNA-AgNCs with DNA programmability and the advantages of DNA assembly in incorporating repetitive and functional moieties into one structure. By the specific modification of the trigger, MBL-AgNCs tethered with the targeting aptamer and partially hybridized duplex, which works as a component of DNA logic platform relying on the combination of cascade strand displacement reaction and specific recognition ability of aptamers, were obtained, respectively. DNA-AgNCs assembled by the aptamer-tethered MBL structure exhibited about 20-fold enhanced detection sensitivity in recognizing cancer cells compared to individual aptamer-tethered DNA-AgNCs. DNA-AgNCs assembled by the duplex-attached MBL exhibited logic performance in analyzing dual cell surface receptors with the assistance of "AND" logic platform, thus identifying cancer cells with high sensitivity and resolution. The facile conjugation of the MBL structure with different functional DNA structures makes it an ideal platform to assemble DNA-AgNCs used for aptamer-based cell recognition, thus broadening the potential applications of DNA-AgNCs.

Multibranched Linear DNA-Controlled Assembly of Silver Nanoclusters and Their Applications in Aptamer-Based Cell Recognition.

In this study, a novel highly sensitive colorimetric platform has been designed for malathion assay based on Fe-N/C SAzyme. The as-synthesized SAzyme can directly oxidize 3,3´,5,5´-tetramethylbenzidine (TMB) to generate blue colored oxidized TMB. L-ascorbic acid-2-phosphate (AA2P), a substrate of acid phosphatase (ACP), could be hydrolyzed to AA, thereafter inhibit the oxidization reaction of TMB, leading to a conspicuous blue color fading. With the addition of malathion hindered the ACP activity and limited the AA production, resulting in the recovery of the catalytic activity of single-atom nanozyme. Under optimized operational conditions, a novel colorimetric assay has been designed for malathion detection with LOD of 0.42 nM. Besides, quantification of malathion in environmental and food samples was achieved based on the proposed strategy. In addition, the successfully integrated paper/smartphone sensor provided sensitive, and rapid, reliable detection of malathion with a LOD of 1 nM.

A colorimetric smartphone-based platform for pesticides detection using Fe-N/C single-atom nanozyme as oxidase mimetics.

Aristolochic acids (AAs) have long been considered as a potent carcinogen due to its nephrotoxicity. Aristolochic acid I (AAI) reacts with DNA to form covalent aristolactam (AL)-DNA adducts, leading to subsequent A to T transversion mutation, commonly referred as AA mutational signature. Previous research inferred that AAs were widely implicated in liver cancer throughout Asia. In this study, we explored whether AAs exposure was the main cause of liver cancer in the context of HBV infection in mainland China. Totally 1256 liver cancer samples were randomly retrieved from 3 medical centers and a refined bioanalytical method was used to detect AAI-DNA adducts. 5.10% of these samples could be identified as AAI positive exposure. Whole genome sequencing suggested 8.41% of 107 liver cancer patients exhibited the dominant AA mutational signature, indicating a relatively low overall AAI exposure rate. In animal models, long-term administration of AAI barely increased liver tumorigenesis in adult mice, opposite from its tumor-inducing role when subjected to infant mice. Furthermore, AAI induced dose-dependent accumulation of AA-DNA adduct in target organs in adult mice, with the most detected in kidney instead of liver. Taken together, our data indicate that AA exposure was not the major threat of liver cancer in adulthood.

Jia Ge

State Key Laboratory of Biochemical Engineering,
Institute of Process Engineering,
State Key Laboratory of Biochemical Engineering, Institute of Process Engineering

Chinese Academy of Sciences

Cellular Affinity of Particle-Stabilized Emulsion to Boost Antigen Internalization

Jia Ge

.css-o250i3{font-size:18px;font-family:Open Sans,sans-serif;line-height:21.6px;}State Key Laboratory of Biochemical Engineering,Institute of Process Engineering,State Key Laboratory of Biochemical Engineering, Institute of Process Engineering

Chinese Academy of Sciences

Cellular Affinity of Particle-Stabilized Emulsion to Boost Antigen Internalization

State Key Laboratory of Biochemical Engineering,
Institute of Process Engineering,
State Key Laboratory of Biochemical Engineering, Institute of Process Engineering