Homo- or heterodimeric compounds that affect dimeric protein function through interaction between monomeric moieties and protein subunits can serve as valuable sources of potent and selective drug candidates. Here, we screened an in-house dimeric natural product collection, and panepocyclinol A (PecA) emerged as a selective and potent STAT3 inhibitor with profound anti-tumor efficacy. Through cross-linking C712/C718 residues in separate STAT3 monomers with two distinct Michael receptors, PecA inhibits STAT3 DNA binding affinity and transcription activity. Molecular dynamics simulation reveals the key conformation changes of STAT3 dimers upon the di-covalent binding with PecA that abolishes its DNA interactions. Furthermore, PecA exhibits high efficacy against anaplastic large T cell lymphoma in vitro and in vivo, especially those with constitutively activated STAT3 or STAT3^Y640F. In summary, our study describes a distinct and effective di-covalent modification for the dimeric compound PecA to disrupt STAT3 function.

Kirsten rat sarcoma viral oncogene homolog (KRAS) protein inhibitors are a promising class of therapeutics, but research on molecules that effectively penetrate the blood-brain barrier (BBB) remains limited, which is crucial for treating central nervous system (CNS) malignancies. Although molecular generation models have recently advanced drug discovery, they often overlook the complexity of biological and chemical factors, leaving room for improvement. In this study, we present a structure-constrained molecular generation workflow designed to optimize lead compounds for both drug efficacy and drug absorption properties. Our approach utilizes a variational autoencoder (VAE) generative model integrated with reinforcement learning for multi-objective optimization. This method specifically aims to enhance BBB permeability (BBBp) while maintaining high-affinity substructures of KRAS inhibitors. To support this, we incorporate a specialized KRAS BBB predictor based on active learning and an affinity predictor employing comparative learning models. Additionally, we introduce two novel metrics, the knowledge-integrated reproduction score (KIRS) and the composite diversity score (CDS), to assess structural performance and biological relevance. Retrospective validation with KRAS inhibitors, AMG510 and MRTX849, demonstrates the framework's effectiveness in optimizing BBBp and highlights its potential for real-world drug development applications. This study provides a robust framework for accelerating the structural enhancement of lead compounds, advancing the drug development process across diverse targets.

Endo-beta-N-acetylglucosaminidase (ENGase) is widely distributed in various organisms. The first reported ENGase activity was detected in Diplococcus pneumoniae in 1971. The protein (Endo D) was purified and its peptide sequence was determined in 1974. Three ENGases (Endo F1-F3) were discovered in Flavobacterium meningosepticum from 1982 to 1993. After that, the activity was detected from different species of bacteria, yeast, fungal, plant, mice, human, etc. Multiple ENGases were detected in some species, such as Arabidopsis thaliana and Trichoderma atroviride. The first preliminary crystallographic analysis of ENGase was conducted in 1994. But to date, only a few ENGases structures have been obtained, and the structure of human ENGase is still missing. The currently identified ENGases were distributed in the GH18 or GH85 families in Carbohydrate-Active enZyme (CAZy) database. GH18 ENGase only has hydrolytic activity, but GH85 ENGase has both hydrolytic and transglycosylation activity. Although ENGases of the two families have similar (β/α)8-TIM barrel structures, the active sites are slightly different. ENGase is an effective tool for glycan detection andglycan editing. Biochemically, ENGase can specifically hydrolyze β‑1,4 glycosidic bond between the twoN-acetylglucosamines (GlcNAc) on core pentasaccharide presented on glycopeptides and/or glycoproteins. Different ENGases may have different substrate specificity. The hydrolysis products are oligosaccharide chains and a GlcNAc or glycopeptides or glycoproteins with a GlcNAc. Conditionally, it can use the two products to produce a new glycopeptides or glycoprotein. Although ENGase is a common presentation in cell, its biological function remains unclear. Accumulated evidences demonstrated that ENGase is a none essential gene for living and a key regulator for differentiation. No ENGase gene was detected in the genomes of Saccharomyces cerevisiae and three other yeast species. Its expression was extremely low in lung. As glycoproteins are not produced by prokaryotic cells, a role for nutrition and/or microbial-host interaction was predicted for bacterium produced enzymes. In the embryonic lethality phenotype of the Ngly1-deficient mice can be partially rescued by Engase knockout, suggesting down regulation of Engase might be a solution for stress induced adaptation. Potential impacts of ENGase regulation on health and disease were presented. Rabeprazole, a drug used for stomach pain as a proton inhibitor, was identified as an inhibitor for ENGase. ENGases have been applied in vitro to produce antibodies with a designated glycan. The two step reactions were achieved by a pair of ENGase dominated for hydrolysis of substrate glycoprotein and synthesis of new glycoprotein with a free glycan of designed structure, respectively. In addition, ENGase was also been used in cell surface glycan editing. New application scenarios and new detection methods for glycobiological engineering are quickly opened up by the two functions of ENGase, especially in antibody remodeling and antibody drug conjugates. The discovery, distribution, structure property, enzymatic characteristics and recent researches in topical model organisms of ENGase were reviewed in this paper. Possible biological functions and mechanisms of ENGase, including differentiation, digestion of glycoproteins for nutrition and stress responding were hypothesised. In addition, the role of ENGase in glycan editing and synthetic biology was discussed. We hope this paper may provide insights for ENGase research and lay a solid foundation for applied and translational glycomics.

Protein as the allergens could lead to allergy. In addition, a widespread class of allergens were known as glycans of N-glycoprotein. N-glycoprotein contained oligosaccharide linked by covalent bonds with protein. Recently,studies implicated that allergy was associated with glycans of heterologous N-glycoprotein found in food, inhalants, insect toxins, etc. The N-glycan structure of N-glycoprotein allergen has exerted an influence on the binding between allergens and IgE, while the recognition and presentation of allergens by antigen-presenting cells (APCs) were also affected. Some researches showed thatN-glycan structure of allergen was remodeled by N-glycosidase, such as cFase I, gpcXylase, as binding of allergen and IgE partly decreased. Thus, allergic problems caused by N-glycoproteins could potentially be solved by modifying or altering the structure ofN-glycoprotein allergens, addressing the root of the issue. Mechanism of N-glycans associated allergy could also be elaborated through glycosylation enzymes, alterations of host glycosylation. This article hopes to provide a separate insight for glycoimmunology perspective, and an alternative strategy for clinical prevention or therapy of allergic diseases.

From the perspective of the physiological basis of liver and kidney sharing the common source in traditional Chinese medicine(TCM),and by integrating the theory of kidney dominating bone,liver dominating tendon,and meridian sinew of TCM as well as the bone resorption and collapse theory,and non-uniform settlement theory and lower-limb musculoskeletal bowstring structure theory of modern orthopedics,the pathogenesis of osteonecrosis of the femoral head(ONFH)under the system of non-uniform settlement during bone resorption and multidimensional composite bowstring working in coordination with the theory of liver-kidney and muscle-bone was explored.The key to the TCM pathogenesis of ONFH lies in the deficiency of the liver and kidney,and then the imbalance of kidney yin-yang leads to the disruption of the dynamic balance of bone formation and bone resorption mediated by osteoblasts-osteoclasts,which manifests as the elevated level of bone metabolism and the enhancement of focal bone resorption in the femoral head,and then leads to the necrosis and collapse of the femoral head.It is considered that the kidney dominates bone,liver dominates tendon,and the tendon and bone together constitute the muscle-bone-joint dynamic and static system of the hip joint.The appearance of collapse destroys the originally balanced muscle-bone-joint system.Moreover,the failure of liver blood in the nourishment of muscles and tendons further exacerbates the imbalance of the soft tissues around the hip joint,accelerates the collapse of the muscle-bone-joint dynamic and static system,speeds up the process of femoral head collapse,and ultimately results in irreversible outcomes.Based on the above pathogenesis,the systematic integrative treatment of ONFH should be based on the TCM holistic concept,focuses on the focal improvement of internal and external blood circulation of the femoral head by various approaches,so as to rebuild the coordination of joint function.Moreover,attention should be paid to the physical constitution of the patients,and therapy of tonifying the kidney and regulating the liver can be used to restore the balance between osteogenesis and osteoblastogenesis,and to reconstruct the muscle-bone-joint system,so as to effectively delay or even prevent the occurrence of ONFH.

italic>Platycodon grandiflorum (Jacq.) A. DC is one of the most commonly used bulk medicinal herbs. It has important value in the fields of medicine, food and cosmetics, and its market demand is increasing year by year, and it has a good development prospect. In this study, based on 403 distribution records and 8 environmental variables, we used Maxent model to predict the potential distribution of P. grandiflorum under climate change. The results showed that the model simulation effect was the best when the Maxent parameter was FC (feature combination) = LQPH (L: linear features; Q: quadratic features; P: product features; H: hinge features) and RM (regularization multiplier) = 2.1, AUC (area under curve) = 0.901, and the model prediction showed that P. grandiflorum was widely distributed in 28 provinces of China under the current climate conditions, with a suitable area of 2 337 419.98 km². Under the influence of climate change in the future, the area of suitable habitat of P. grandiflorum showed a decreasing trend, and the distribution center as a whole showed a trend of northward and eastward shift. The distribution area of P. grandiflorum in the three main producing areas is affected by climate change, and the overall trend is that the future suitable distribution area of Chifeng in Inner Mongolia increases, while the future suitable distribution area of Zibo in Shandong and Taihe, Bozhou in Anhui decreases or even disappears under the SSP5-8.5 scenario (shared socioeconomic pathways). It is suggested to maintain and protect the ecological environment and germplasm resources of the reserved area suitable for the growth of P. grandiflorum, and increase the cultivation research in the expansion area of P. grandiflorum, so as to lay a foundation for the subsequent expansion of P. grandiflorum planting and to promote the protection and sustainable development of P. grandiflorum resources.

Objective To establish a sensitive,accurate and simple method for the determination of methotrexate and methotrexate polyglutamates(MTXPG2 and MTXPG3)in human erythrocytes.Methods A dual three element gradient liquid chromatograph with a fluorescence detector was used,the C18-WP column(20 mm ×4 mm,5μm)was used as the online SPE column,and the Athena C18-WP column(150 mm x4.6 mm,3 μm)was used as the analytical column.Erythrocyte lysate was precipitated with zinc sulphate-10％formic acid methanol(100:90,v/v),and postcolumn photo-oxidation of MTXPGs to fluorescent analytes using H2O2.The fluorescence excitation wavelength was 274 nm,the emission wavelength was 470 nm,the column temperature was 40 ℃,and the injection volume was 100 μL.The specificity,standard curve,lower limit of quantitation,precision,recovery and stability of the method were investigated.Results MTX,MTXPG2 and MTXPG3 had good linearity in the range of 12.5-400.0 nmol·L-1.The standard curve of MTX was y=763.8x-2 961.1(R2=0.999 5),and the extraction recovery rate was 60.7％-66.1％;the standard curve of MTXPG2 was y=1 017.8x-239.8(R2=0.998 4),and the extraction recovery rate was 67.2％-67.3％;the standard curve of MTXPG3 was y=1 069.1x-819.6(R2=0.999 4),the extraction recovery rate was 62.9％-70.1％.Intra-day precision RSD＜8.8％,inter-day precision RSD＜10.8％.Conclusion This method is accurate and reproducibility,and the online solid-phose extraction enrichment and separation of target compounds simplify the sample pretreatment steps,improve the analysis efficiency,and is suitable for detecting the concentration of MTX,MTXPG2 and MTXPG3 in erythrocytes of patients with rheumatoid arthritis.

Objective To find potential biomarkers and analyzing metabolic pathways of the treatment by honey-processed Hedysari Radix,the cecal contents of rats with spleen-Qi deficiency were used as samples for analysis.Methods Sixty male SD rats were randomly divided into blank,model,experimental and control groups.The rats in other groups except the control group were carried out by using the three-factor compound modeling method of bitter-cold diarrhea,excessive exertion and hunger and satiety disorders.Experimental group was given 12.60 g·kg-1 honey-processed Hedysari Radix;control group was given 0.63 g·kg-1 lactobacillus bifidum triplex tabletsa;control and model groups received with equal volume of distilled water for a total of 15 days.Measure body weight,anal temperature,immune organ index of rats.Ultra-pressure liquid chromatography-quadrupole-exactive-mass spectrometry technology was used to measure the levels of endogenous metabolites in cecum contents.Orthogonal partial least squares discriminant analysis and database"Kyoto Encyclopedia of Genes and Genomes"were used to identify potential differential metabolites and possible metabolic pathways.Results After the intervention,the average body weight of the experimental,control,model and blank groups was(216.87±7.85),(210.96±9.03),(159.47±5.18)and(293.51±22.98)g;anal temperature was(36.14±0.48),(35.40±0.64),(34.50±0.78)and(36.61±0.34)℃;the thymus indexes were(1.19±0.20),(1.24±0.25),(0.47±0.15)and(1.31±0.21)mg·g-1;the spleen indexes were(1.95±0.33),(2.18±0.28),(1.61±0.27)and(2.29±0.24)mg·g-1.Compared with the model group,the above indexes of the experimental group and the control group were significantly increased(all P＜0.01).A total of 14 potential biomarkers of Honey-processed Hedysari Radix in treating spleen-Qi deficiency syndrome were screened out in this study,which mainly involved amino acid metabolism such as tryptophan and glutamate,riboflavin metabolism and adenosine 5'-monophosphate-activated protein kinase metabolism.Conclusion Honey-processed Hedysari Radix can further protect the intestinal mucosal barrier and reduce the intestinal inflammatory response by improving the metabolic level of cecum contents in rats with spleen-Qi deficiency in cecum contents,thus exerting the effect of strengthening the spleen and tonifying the Qi.

Radiation mainly comes from medical radiation,industrial radiation,nuclear waste and atmospheric ultraviolet radiation,etc.,radiation is divided into ionizing radiation and non-ionizing radiation.Studying the effects of ionizing and non-ionizing radiation on drug metabolism,understanding the absorption and distribution of drugs in the body after radiation and the speed of elimination under radiation conditions can provide reasonable guidance for clinical medication.This article reviews the effects of radiation on the pharmacokinetics of different drugs,elaborates the changes of different pharmacokinetics under radiation state,and discusses the reasons for the changes.