A molecular sheaf: doubly threaded [6]rotaxane.

We report that the use of a hydrogen-bonded pyrimidine-macrocycle complex can efficiently facilitate the threading of two bispyridinium ethylenes into four rings, as evidenced by X-ray crystallography of its precursor, offering a rare example of a doubly threaded [6]rotaxane in 91% yield. The unusual architecture is found to be stable with no dethreading despite the large ring size of the macrocycle with respect to the stopper.

Phycosphere bacterial disturbance of Saccharina japonica caused by white rot disease relates to seawater nutrients.

In mid-November 2021, there were large areas of white rot disease on cultivated Saccharina japonica in Rongcheng City, China, and diseases were undetected on Sargassum horneri and Porphyra yezoensis. The disturbance direction of bacterial community in the phycosphere after disease outbreak and the relationship with seawater nutrients remain unclear. Here, in situ studies of bacterial community in the non-diseased and diseased areas (Shawo and Dongchu islands) and seawater nutrient levels were carried out. 16S rRNA sequencing showed that the bacterial richness of the studied seaweeds increased in the diseased area. Only in S. japonica, Algitalea outcompeted abundant primary bacteria with probiotic relationships to the host of the non-diseased area, and dominated in the diseased area (17.6% of the total abundance). Nitrogen and phosphorus levels in seawater were 57.8% and 19.6% higher in the non-diseased area than those in the diseased area, respectively, and were strongly correlated with the phycosphere bacteria at the family level of S. japonica. There was no difference in potential pathogenicity between the two areas, while positive signal communications decreased, and nitrogen cycle, chemoheterotrophy, and cellulolysis increased in the diseased area compared to the non-diseased area. Overall, white rot disease caused a structural disturbance in phycosphere bacterial community of S. japonica that related to seawater nutrient levels. Enriched degraders and altered bacterial community functions may exacerbate the disease. This evaluation will provide information for white rot disease management to prevent and mitigate the occurrence of S. japonica outbreaks.

Quantum phase synchronization via exciton-vibrational energy dissipation sustains long-lived coherence in photosynthetic antennas.

The lifetime of electronic coherences found in photosynthetic antennas is known to be too short to match the energy transfer time, rendering the coherent energy transfer mechanism inactive. Exciton-vibrational coherence time in excitonic dimers which consist of two chromophores coupled by excitation transfer interaction, can however be much longer. Uncovering the mechanism for sustained coherences in a noisy biological environment is challenging, requiring the use of simpler model systems as proxies. Here, via two-dimensional electronic spectroscopy experiments, we present compelling evidence for longer exciton-vibrational coherence time in the allophycocyanin trimer, containing excitonic dimers, compared to isolated pigments. This is attributed to the quantum phase synchronization of the resonant vibrational collective modes of the dimer, where the anti-symmetric modes, coupled to excitonic states with fast dephasing, are dissipated. The decoupled symmetric counterparts are subject to slower energy dissipation. The resonant modes have a predicted nearly 50% reduction in the vibrational amplitudes, and almost zero amplitude in the corresponding dynamical Stokes shift spectrum compared to the isolated pigments. Our findings provide insights into the mechanisms for protecting coherences against the noisy environment.

Glucosylceramide accumulation in microglia triggers STING-dependent neuroinflammation and neurodegeneration in mice.

Mutations in the gene encoding the lysosomal enzyme glucocerebrosidase (GCase) are responsible for Gaucher disease (GD) and are considered the strongest genetic risk factor for Parkinson's disease (PD) and Lewy body dementia (LBD). GCase deficiency leads to extensive accumulation of glucosylceramides (GCs) in cells and contributes to the neuropathology of GD, PD, and LBD by triggering chronic neuroinflammation. Here, we investigated the mechanisms by which GC accumulation induces neuroinflammation. We found that GC accumulation within microglia induced by pharmacological inhibition of GCase triggered STING-dependent inflammation, which contributed to neuronal loss both in vitro and in vivo. GC accumulation in microglia induced mitochondrial DNA (mtDNA) leakage to the cytosol to trigger STING-dependent inflammation. Rapamycin, a compound that promotes lysosomal activity, improved mitochondrial function, thereby decreasing STING signaling. Furthermore, lysosomal damage caused by GC accumulation led to defects in the degradation of activated STING, further exacerbating inflammation mediated by microglia. Thus, limiting STING activity may be a strategy to suppress neuroinflammation caused by GCase deficiency.

Engineering Substrate Promiscuity of Nucleoside Phosphorylase Via an Insertions-Deletions Strategy.

Nucleoside phosphorylases (NPs) are the key enzymes in the nucleoside metabolism pathway and are widely employed for the synthesis of nucleoside analogs, which are difficult to access via conventional synthetic methods. NPs are generally classified as purine nucleoside phosphorylase (PNP) and pyrimidine or uridine nucleoside phosphorylase (PyNP/UP), based on their substrate preference. Here, based on the evolutionary information on the NP-I family, we adopted an insertions-deletions (InDels) strategy to engineer the substrate promiscuity of nucleoside phosphorylase AmPNPΔS2V102 K, which exhibits both PNP and UP activities from a trimeric PNP (AmPNP) of Aneurinibacillus migulanus. Furthermore, the AmPNPΔS2V102 K exerted phosphorylation activities toward arabinose nucleoside, fluorosyl nucleoside, and dideoxyribose, thereby broadening the unnatural-ribose nucleoside substrate spectrum of AmPNP. Finally, six purine nucleoside analogues were successfully synthesized, using the engineered AmPNPΔS2V102 K instead of the traditional "two-enzymes PNP/UP" approach. These results provide deep insights into the catalytic mechanisms of the PNP and demonstrate the benefits of using the InDels strategy to achieve substrate promiscuity in an enzyme, as well as broadening the substrate spectrum of the enzyme.

Fatty acid esters of hydroxy fatty acids: A potential treatment for obesity-related diseases.

Obesity, a burgeoning worldwide health system challenge, is associated with multiple chronic diseases, including diabetes and chronic inflammation. Fatty acid esters of hydroxy fatty acids (FAHFAs) are newly identified lipids with mitigating and anti-inflammatory effects in diabetes. Increasing work has shown that FAHFAs exert antioxidant activity and enhance autophagy in neuronal cells and cardiomyocytes. We systematically summarized the biological activities of FAHFAs, including their regulatory effects on diabetes and inflammation, antioxidant activity, and autophagy augmentation. Notably, the structure-activity relationships and potential biosynthesis of FAHFAs are thoroughly discussed. FAHFAs also showed potential roles as diagnostic biomarkers. FAHFAs are a class of resources with promising applications in the biomedical field that require in-depth research and hotspot development, as their structure has not been fully resolved and their biological activity has not been fully revealed.

The ever-lasting green tides: What can we do？.

Macroalgal blooms (Green tides) are occurring more frequently in many regions of the world because of the combined effects of increasingly intense human activity and climate change. In the last decade, the world's largest Ulva prolifera green tide has become a recurrent phenomenon, appearing every summer in the southern Yellow Sea, China. Green tides can hurt coastal tourism and eradicate aquaculture and artisanal fishing. Eutrophication in nearshore waters is the ultimate explanation for the explosive growth of the macroalgal biomass, but the specific course of each nearshore green tide is often complex and requires in-depth and extensive research to develop effective mitigation strategies. Researchers have undertaken extensive studies on the prevention, control and mitigation of large-scale green algal blooms, and felicitated the utilization of green tide harmful biomass through bio-refining, bioconversion and other measures. However, due to the large-scale and trans-regional nature of the green tide, the government's administrative coordination measures are also essential for effective control. Nevertheless, it is becoming increasingly urgent to prevent and control the bloom at the early stage, and efficiently salvage and use these valuable raw materials.

Dynamic Changes in Neuroglial Reaction and Tissue Repair after Photothrombotic Stroke in Neonatal Mouse.

Perinatal and neonatal ischemic stroke is a significant cause of cognitive and behavioral impairments. Further research is needed to support models of neonatal ischemic stroke and advance our understanding of the mechanisms of infarction formation following such strokes. We used two different levels of photothrombotic stroke (PTS) models to assess stroke outcomes in neonatal mice. We measured brain damage, dynamic changes in glial cells, and neuronal expression at various time points within two weeks following ischemic injury. Our results from 2,3,5-Triphenyltetrazolium chloride (TTC) staining and immunofluorescence staining showed that in the severe group, a dense border of astrocytes and microglia was observed within 3 days post infarct. This ultimately resulted in the formation of a permanent cortical cavity, accompanied by neuronal loss in the surrounding tissues. In the mild group, a relatively sparse arrangement of glial borders was observed 7 days post infarct. This was accompanied by intact cortical tissue and the restoration of viability in the brain tissue beyond the glial boundary. Additionally, neonatal ischemic injury leads to the altered expression of key molecules such as Aldh1L1 and Olig2 in immature astrocytes. In conclusion, we demonstrated the dynamic changes in glial cells and neuronal expression following different degrees of ischemic injury in a mouse model of PTS. These findings provide new insights for studying the cellular and molecular mechanisms underlying neuroprotection and neural regeneration after neonatal ischemic injury.

[Investigation on the signaling pathways in the mechanism of hyperoxia-induced acute lung injury based on transcriptomics sequencing].

OBJECTIVE: To observe and verify the changes of transcriptome in hyperoxia-induced acute lung injury (HALI), and to further clarify the changes of pathways in HALI. METHODS: Twelve healthy male C57BL/6J mice were randomly divided into normoxia group and HALI group according to the random number table, with 6 mice in each group. The mice in the normoxia group were fed normally in the room, and the mice in the HALI group was exposed to 95% oxygen to reproduce the HALI animal model. After 72 hours of hyperoxia exposure, the lung tissues were taken for transcriptome sequencing, and then Kyoto Encyclopedia of Genes and Genomes database (KEGG) pathway enrichment analysis was performed. The pathological changes of lung tissue were observed under light microscope after hematoxylin-eosin (HE) staining. Real-time fluorescence quantitative reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting were used to verify the key molecules in the signal pathways closely related to HALI identified by transcriptomics analysis. RESULTS: Transcriptomic analysis showed that hyperoxia induced 537 differentially expressed genes in lung tissue of mice as compared with the normoxia group including 239 up-regulated genes and 298 down-regulated genes. Further KEGG pathway enrichment analysis identified 20 most significantly enriched pathway entries, and the top three pathways were ferroptosis signaling pathway, p53 signaling pathway and glutathione (GSH) metabolism signaling pathway. The related genes in the ferroptosis signaling pathway included the up-regulated gene heme oxygenase-1 (HO-1) and the down-regulated gene solute carrier family 7 member 11 (SLC7A11). The related genes in the p53 signaling pathway included the up-regulated gene tumor suppressor gene p53 and the down-regulated gene murine double minute 2 (MDM2). The related gene in the GSH metabolic signaling pathway was up-regulated gene glutaredoxin 1 (Grx1). The light microscope showed that the pulmonary alveolar structure of the normoxia group was normal. In the HALI group, the pulmonary alveolar septum widened and thickened, and the alveolar cavity shrank or disappeared. RT-RCR and Western blotting confirmed that compared with the normoxia group, the mRNA and protein expressions of HO-1 and p53 in lung tissue of the HALI group were significantly increased [HO-1 mRNA (2-ΔΔCt): 2.16±0.17 vs. 1.00±0.00, HO-1 protein (HO-1/ß-actin): 1.05±0.01 vs. 0.79±0.01, p53 mRNA (2-ΔΔCt): 2.52±0.13 vs. 1.00±0.00, p53 protein (p53/ß-actin): 1.12±0.02 vs. 0.58±0.03, all P < 0.05], and the mRNA and protein expressions of Grx1, MDM2, SLC7A11 were significantly decreased [Grx1 mRNA (2-ΔΔCt): 0.53±0.05 vs. 1.00±0.00, Grx1 protein (Grx1/ß-actin): 0.54±0.03 vs. 0.93±0.01, MDM2 mRNA (2-ΔΔCt): 0.48±0.03 vs. 1.00±0.00, MDM2 protein (MDM2/ß-actin): 0.57±0.02 vs. 1.05±0.01, SLC7A11 mRNA (2-ΔΔCt): 0.50±0.06 vs. 1.00±0.00, SLC7A11 protein (SLC7A11/ß-actin): 0.72±0.03 vs. 0.98±0.01, all P < 0.05]. CONCLUSIONS: HALI is closely related to ferroptosis, p53 and GSH metabolism signaling pathways. Targeting the key targets in ferroptosis, p53 and GSH metabolism signaling pathways may be an important strategy for the prevention and treatment of HALI.

Advances in peptide-based drug delivery systems.

Drug delivery systems (DDSs) are designed to deliver drugs to their specific targets to minimize their toxic effects and improve their susceptibility to clearance during targeted transport. Peptides have high affinity, low immunogenicity, simple amino acid composition, and adjustable molecular size; therefore, most peptides can be coupled to drugs via linkers to form peptide-drug conjugates (PDCs) and act as active pro-drugs. PDCs are widely thought to be promising DDSs, given their ability to improve drug bio-compatibility and physiological stability. Peptide-based DDSs are often used to deliver therapeutic substances such as anti-cancer drugs and nucleic acid-based drugs, which not only slow the degradation rate of drugs in vivo but also ensure the drug concentration at the targeted site and prolong the half-life of drugs in vivo. This article provides an profile of the advancements and future development in functional peptide-based DDSs both domestically and internationally in recent years, in the expectation of achieving targeted drug delivery incorporating functional peptides and taking full advantage of synergistic effects.

Effect of nitrogen reduction by chemical fertilization with green manure (Vicia sativa L.) on soil microbial community, nitrogen metabolism and and yield of Uncaria rhynchophylla by metagenomics.

Uncaria rhynchophylla is an important herbal medicine, and the predominant issues affecting its cultivation include a single method of fertilizer application and inappropriate chemical fertilizer application. To reduce the use of inorganic nitrogen fertilization and increase the yield of Uncaria rhynchophylla, field experiments in 2020-2021 were conducted. The experimental treatments included the following categories: S1, no fertilization; S2, application of chemical NPK fertilizer; and S3-S6, application of chemical fertilizers and green manures, featuring nitrogen fertilizers reductions of 0%, 15%, 30%, and 45%, respectively. The results showed that a moderate application of nitrogen fertilizer when combined with green manure, can help alleviate soil acidification and increase urease activity. Specifically, the treatment with green manure provided in a 14.71-66.67% increase in urease activity compared to S2. Metagenomics sequencing results showed a decrease in diversity in S3, S4, S5, and S6 compared to S2, but the application of chemical fertilizer with green manure promoted an increase in the relative abundance of Acidobacteria and Chloroflexi. In addition, the nitrification pathway displayed a progressive augmentation in tandem with the reduction in nitrogen fertilizer and application of green manure, reaching its zenith at S5. Conversely, other nitrogen metabolism pathways showed a decline in correlation with diminishing nitrogen fertilizer dosages. The rest of the treatments showed an increase in yield in comparison to S1, S5 showing significant differences (p < 0.05). In summary, although S2 demonstrate the ability to enhance soil microbial diversity, it is important to consider the long-term ecological impacts, and S5 may be a better choice.

Gpnmb silencing protects against hyperoxia-induced acute lung injury by inhibition of mitochondrial-mediated apoptosis.

Background: Hyperoxia-induced acute lung injury (HALI) is a complication to ventilation in patients with respiratory failure, which can lead to acute inflammatory lung injury and chronic lung disease. The aim of this study was to integrate bioinformatics analysis to identify key genes associated with HALI and validate their role in H2O2-induced cell injury model.Methods: Integrated bioinformatics analysis was performed to screen vital genes involved in hyperoxia-induced lung injury (HLI). CCK-8 and flow cytometry assays were performed to assess cell viability and apoptosis. Western blotting was performed to assess protein expression.Results: In this study, glycoprotein non-metastatic melanoma protein B (Gpnmb) was identified as a key gene in HLI by integrated bioinformatics analysis of 4 Gene Expression Omnibus (GEO) datasets (GSE97804, GSE51039, GSE76301 and GSE87350). Knockdown of Gpnmb increased cell viability and decreased apoptosis in H2O2-treated MLE-12 cells, suggesting that Gpnmb was a proapoptotic gene during HALI. Western blotting results showed that knockdown of Gpnmb reduced the expression of Bcl-2 associated X (BAX) and cleaved-caspase 3, and increased the expression of Bcl-2 in H2O2 treated MLE-12 cells. Furthermore, Gpnmb knockdown could significantly reduce reactive oxygen species (ROS) generation and improve the mitochondrial membrane potential.Conclusion: The present study showed that knockdown of Gpnmb may protect against HLI by repressing mitochondrial-mediated apoptosis.

On-site portable detection of gaseous methyl iodide using an electrochemical method.

We report an electrochemical device for portable on-site detection of gaseous CH3I based on PVIm-F for the first time. The device achieves detection of gaseous CH3I with a significant selectivity and a low detection limit (0.474 ppb) in 20 min at 50 °C and 50% relative humidity, which is of great significance for achieving real-time on-site monitoring of radioactive hazardous environments.

Aggregating Synechococcus contributes to particle organic carbon export in coastal estuarine waters: Its lineage features and assembly processes.

The release and deposition of phytoplankton-derived particulate organic matter is crucial in marine carbon export, yet the roles of picoplankton in these processes were seldom considered. Therefore, this study aimed to shed light on the matter by investigating the aggregating (AG) lifestyle of Synechococcus, a main group of picoplankton, in the coastal waters of the Yellow River Estuary with ample sediments acting as ballast minerals. We revealed that AG Synechococcus constituted a substantial portion, maximally reaching up to 85.4 %, of the total Synechococcus population. Pearson correlations and random forest (RF) regression analyses found significant connections (p < 0.01) between AG Synechococcus and the content of particulate organic carbon (POC), which emphasized its underlying role in facilitating POC export in this region. Furthermore, by employing high-throughput sequencing of the RNA polymerase gene (rpoC1), it was demonstrated that S5.1 clade I exhibited a significantly higher proportion in the AG fraction than in the free-living (FL) fraction (p < 0.05). This suggests distinct inclinations in the phylogenetic preference for different Synechococcus lineages between different lifestyles in the studied area. Finally, we ascertained "small-world" and higher robustness attributes of aggregates formed through the co-occurrence construction between Synechococcus and heterotrophic bacteria, likely facilitated by the reciprocal exchange of carbon and nitrogen elements. Overall, these findings have implications for our understanding of the role of Synechococcus in the ecology and biogeochemistry of marine ecosystems, and they are significant for more accurately evaluating the contribution of picophytoplankton in ocean carbon export.

Evolving the 3-O/6-O regiospecificity of a microbial glycosyltransferase for efficient production of ginsenoside Rh1 and unnatural ginsenoside.

Glycosyltransferase is a popular and promising enzyme to produce high-value-added natural products. Rare ginsenoside Rh1 and unnatural ginsenoside 3ß-O-Glc-PPT are promising candidates for drugs. Herein, the microbial glycosyltransferase UGTBL1 was able to catalyze the 20(S)-protopanaxatriol (PPT) 3-O/6-O-glycosylation with poor 6-O-regiospecificity. A structure-guided strategy of mutations involving loop engineering, PSPG motif evolution, and access tunnel engineering was proposed to engineer the enzyme UGTBL1. The variant I62R/M320H/P321Y/N170A from protein engineering achieved a great improvement in 6-O regioselectivity which increased from 10.98 % (WT) to 96.26 % and a booming conversion of 95.57 % for ginsenoside Rh1. A single mutant M320W showed an improved 3-O regioselectivity of 84.83 % and an increased conversion of 98.13 % for the 3ß-O-glc-PPT product. Molecular docking and molecular dynamics (MD) simulations were performed to elucidate the possible molecular basis of the regiospecificity and catalytic activity. The unprecedented high titer of ginsenoside Rh1 (20.48 g/L) and 3ß-O-Glc-PPT (18.04 g/L) was attained with high regioselectivity and yields using fed-batch cascade reactions from UDPG recycle, which was the highest yield reported to date. This work could provide an efficient and cost-effective approach to the valuable ginsenosides.

Therapeutic effect of phycocyanin on chronic obstructive pulmonary disease in mice.

INTRODUCTION: The prevention and treatment of chronic obstructive pulmonary disease (COPD) is closely tied to antioxidation and anti-inflammation. Phycocyanin (PC) has numerous pharmacological effects, such as antioxidation and anti-inflammation. However, it remains unclear whether PC can play a therapeutic role in COPD. OBJECTIVE: As inflammation and oxidative stress can aggravate COPD, this study is to explore the effect of PC on COPD mice and its mechanisms. METHODS: The COPD mice model was established by exposing them to lipopolysaccharide (LPS) and cigarette smoke (CS); PC was administrated in a concentration of 50 mg/kg for 30 days. On the last day, lung function was measured, and bronchoalveolar lavage fluid (BALF) was obtained and classified for cells. Lung tissue pathological change was analyzed, and organ indices statistics were measured. Based on molecular docking, the mechanism was explored with Western blotting, immunohistochemical, and immunofluorescence in vivo and in vitro. RESULTS: PC significantly ameliorated the pulmonary function of COPD mice and reduced inflammation of the lung (p < 0.05), and hematoxylin and eosin (H&E) staining showed PC depressed lung inflammatory cell accumulation and emphysema. Periodic acid Schiff (PAS) and Masson staining revealed that PC retarded goblet cells metaplasia and collagen deposition (p < 0.05). In addition, in vivo PC regulated Heme oxygenase 1 (HO-1) (p < 0.05) and NAD(P)H dehydrogenase quinone 1 (NQO1) level (p < 0.01) in the lung, as well as NOX2 level in pulmonary macrophages. Molecular docking results indicate that phycocyanobilin (PCB) in PC had a good binding site in Keap1 and NOX2 proteins; the phycocyanobilin-bound phycocyanin peptide (PCB-PC-peptide) was obtained for further studies. In vitro, PCB-PC-peptide could depress the phospho-NF-E2-related factor 2 (p-Nrf2) and NQO1 protein expression in RAW264.7 cells induced by cigarette smoke extract (CSE) (p < 0.05). CONCLUSION: PC exerts beneficial effects on COPD via anti-inflammatory and antioxidative stress, which may be achieved through PCB.

Monotropein Induced Apoptosis and Suppressed Cell Cycle Progression in Colorectal Cancer Cells.

OBJECTIVE: To determine whether monotropein has an anticancer effect and explore its potential mechanisms against colorectal cancer (CRC) through network pharmacology and molecular docking combined with experimental verification. METHODS: Network pharmacology and molecular docking were used to predict potential targets of monotropein against CRC. Cell counting kit assay, plate monoclonal assay and microscopic observation were used to investigate the antiproliferative effects of monotropein on CRC cells HCT116, HT29 and LoVo. Flow cytometry and scratch assay were used to analyze apoptosis and cell cycle, as well as cell migration, respectively in HCT116, HT29, and LoVo cells. Western blotting was used to detect the expression of proteins related to apoptosis, cell cycle, and cell migration, and the expression of proteins key to the Akt pathway. RESULTS: The Gene Ontology and Reactome enrichment analyses indicated that the anticancer potential of monotropein against CRC might be involved in multiple cancer-related signaling pathways. Among these pathways, RAC-beta serine/threonine-protein kinase (Akt1, Akt2), cyclin-dependent kinase 6 (CDK6), matrix metalloproteinase-9 (MMP9), epidermal growth factor receptor (EGFR), cell division control protein 42 homolog (CDC42) were shown as the potential anticancer targets of monotropein against CRC. Molecular docking suggested that monotropein may interact with the 6 targets (Akt1, Akt2, CDK6, MMP9, EGFR, CDC42). Subsequently, cell activity of HCT116, HT29 and LoVo cell lines were significantly suppressed by monotropein (P<0.05). Furthermore, our research revealed that monotropein induced cell apoptosis by inhibiting Bcl-2 and increasing Bax, induced G1-S cycle arrest in colorectal cancer by decreasing the expressions of CyclinD1, CDK4 and CDK6, inhibited cell migration by suppressing the expressions of CDC42 and MMP9 (P<0.05), and might play an anticancer role through Akt signaling pathway. CONCLUSION: Monotropein exerts its antitumor effects primarily by arresting the cell cycle, causing cell apoptosis, and inhibiting cell migration. This indicates a high potential for developing novel medication for treating CRC.

Structural framework for the understanding spectroscopic and functional signatures of the cyanobacterial Orange Carotenoid Protein families.

The Orange Carotenoid Protein (OCP) is a unique photoreceptor crucial for cyanobacterial photoprotection. Best studied Synechocystis sp. PCC 6803 OCP belongs to the large OCP1 family. Downregulated by the Fluorescence Recovery Protein (FRP) in low-light, high-light-activated OCP1 binds to the phycobilisomes and performs non-photochemical quenching. Recently discovered families OCP2 and OCP3 remain structurally and functionally underexplored, and no systematic comparative studies have ever been conducted. Here we present two first crystal structures of OCP2 from morphoecophysiologically different cyanobacteria and provide their comprehensive structural, spectroscopic and functional comparison with OCP1, the recently described OCP3 and all-OCP ancestor. Structures enable correlation of spectroscopic signatures with the effective number of hydrogen and discovered here chalcogen bonds anchoring the ketocarotenoid in OCP, as well as with the rotation of the echinenone's ß-ionone ring in the CTD. Structural data also helped rationalize the observed differences in OCP/FRP and OCP/phycobilisome functional interactions. These data are expected to foster OCP research and applications in optogenetics, targeted carotenoid delivery and cyanobacterial biomass engineering.

Advances in biosynthesis of peptide drugs: Technology and industrialization.

Peptide drugs are developed from endogenous or synthetic peptides with specific biological activities. They have advantages of strong target specificity, high efficacy and low toxicity, thus showing great promise in the treatment of many diseases such as cancer, infections, and diabetes. Although an increasing number of peptide drugs have entered market in recent years, the preparation of peptide drug substances is yet a bottleneck problem for their industrial production. Comparing to the chemical synthesis method, peptide biosynthesis has advantages of simple synthesis, low cost, and low contamination. Therefore, the biosynthesis technology of peptide drugs has been widely used for manufacturing. Herein, we reviewed the development of peptide drugs and recent advances in peptide biosynthesis technology, in order to shed a light to the prospect of industrial production of peptide drugs based on biosynthesis technology.

How can Phycobilisome, the unique light harvesting system in certain algae working highly efficiently: The connection in between structures and functions.

Algae, which are ubiquitous in ecosystems, have evolved a variety of light-harvesting complexes to better adapt to diverse habitats. Phycobilisomes/phycobiliproteins, unique to cyanobacteria, red algae, and certain cryptomonads, compensate for the lack of chlorophyll absorption, allowing algae to capture and efficiently transfer light energy in aquatic environments. With the advancement of microscopy and spectroscopy, the structure and energy transfer processes of increasingly complex phycobilisomes have been elucidated, providing us with a vivid portrait of the dynamic adaptation of their structures to the light environment in which algae thrive: 1) Cyanobacteria living on the surface of the water use short, small phycobilisomes to absorb red-orange light and reduce the damage from blue-violet light via multiple methods; 2) Large red algae inhabiting the depths of the ocean have evolved long and dense phycobilisomes containing phycoerythrin to capture the feeble blue-green light; 3) In far-red light environments such as caves, algae use special allophycocyanin cores to optimally utilize the far-red light; 4) When the environment shifts, algae can adjust the length, composition and density of their rods to better adapt; 5) By carefully designing the position of the pigments, phycobilisomes can transfer light energy to the reaction center with nearly 100% efficiency via three energy transfer processes.