Climate, litter quality and radiation duration jointly regulate the net effect of UV radiation on litter decomposition.

Photodegradation via ultraviolet (UV) radiation is an important factor driving plant litter decomposition. Despite increasing attention to the role of UV photodegradation in litter decomposition, the specific impact of UV radiation on the plant litter decomposition stage within biogeochemical cycles remains unclear at regional and global scales. To clarify the variation rules of magnitude of UV effect on plant litter decomposition and their regulatory factors, we conducted a meta-analysis based on 54 published papers. Our results indicated that UV significantly promoted the mass loss of litter by facilitating decay of carbonaceous fractions and release of nitrogen and phosphorus. The promotion effect varied linearly or non-linearly with the time that litter exposed to UV, and with climatic factors. The UV effect on litter decomposition decreased first than increased on precipitation and temperature gradients, reaching its minimum in the area with a precipitation of 400-600 mm, and a temperature of 15-20 °C. This trend might be attributed to a potential equilibrium between the photofacilitation and photo-inhibition effects of UV under this condition. This variation in UV effect on precipitation gradient was in agreement with the fact that UV photodegradation effect was weakest in grassland ecosystems compared to that in forest and desert ecosystems. In addition, initial litter quality significantly influenced the magnitude of UV effect, but had no influence on the correlation between UV effect and climate gradient. Litter with lower initial nitrogen and lignin content shown a greater photodegradation effect, whereas those with higher hemicellulose and cellulose content had a greater photodegradation effect. Our study provides a comprehensive understanding of photodegradation effect on plant litter decomposition, indicates potentially substantial impacts of global enhancements of litter decomposition by UV, and highlights the necessity to quantify the contribution of photochemical minerallization pathway and microbial degradation pathway in litter decomposition.

Proteomic Ligandability Maps of Spirocycle Acrylamide Stereoprobes Identify Covalent ERCC3 Degraders.

Covalent chemistry coupled with activity-based protein profiling (ABPP) offers a versatile way to discover ligands for proteins in native biological systems. Here, we describe a set of stereo- and regiochemically defined spirocycle acrylamides and the analysis of these electrophilic "stereoprobes" in human cancer cells by cysteine-directed ABPP. Despite showing attenuated reactivity compared to structurally related azetidine acrylamide stereoprobes, the spirocycle acrylamides preferentially liganded specific cysteines on diverse protein classes. One compound termed ZL-12A promoted the degradation of the TFIIH helicase ERCC3. Interestingly, ZL-12A reacts with the same cysteine (C342) in ERCC3 as the natural product triptolide, which did not lead to ERCC3 degradation but instead causes collateral loss of RNA polymerases. ZL-12A and triptolide cross-antagonized one another's protein degradation profiles. Finally, we provide evidence that the antihypertension drug spironolactone─previously found to promote ERCC3 degradation through an enigmatic mechanism─also reacts with ERCC3_C342. Our findings thus describe monofunctional degraders of ERCC3 and highlight how covalent ligands targeting the same cysteine can produce strikingly different functional outcomes.

Deciphering the epidemiological dynamics: Toxoplasma gondii seroprevalence in mainland China's food animals, 2010-2023.

Background: Toxoplasma gondii (T. gondii) is a significant protozoan pathogen among food animals. Despite the threat to public health by T. gondii infections, there's limited understanding of its seroprevalence and trends in food animals across mainland China. This study aimed to estimate the seroprevalence of T. gondii infections among swine, sheep, goats, chickens, and cattle in mainland China from 2010 to 2023. Methods: We searched cross-sectional studies published between 2010 and 2023 that reported the prevalence of T. gondii in food animals from databases including PubMed, Embase, Web of Science, China Biology Medicine Disc (CBM), China National Knowledge Infrastructure (CNKI), Wanfang data, and the China Science and Technology Journal Database (CQVIP). We performed subgroup analyses to explore the impact of different factors on the seroprevalence of T. gondii. Pooled estimates of T. gondii seroprevalence were calculated with a random-effects model. Results: An analysis of 184 studies involving 211985 animals revealed a T. gondii overall seroprevalence of 15.3% (95% CI: 13.1-17.8). Although the seroprevalence of food animals across mainland China was relatively stable from 2010 to 2023, notable variations were observed across different animal types and regions (P < 0.01), along with changes in geographical distribution. Sample type, detection method, animal age, and history of abortion were identified as key risk factors for T. gondii seroprevalence. Conclusion: The study conducted a meta-analysis on the seroprevalence of T. gondii in mainland China's Food Animals from 2010 to 2023, and identified key risk factors. These findings advance our understanding of T. gondii infection dynamics, offering critical insights for developing control strategies and guiding public health policies.

Self-assembled nanoparticles of acid-induced fish (Cyprinus carpio L.) scale gelatin: Structure, physicochemical properties, and application for loading curcumin.

This work expands the functionality of fish scale gelatin (FSG) as a carrier of hydrophobic bioactive substances. The hydrophobicity of FSG was enhanced to promote its interaction with hydrophobic curcumin and to increase its bioavailability. This results in a remarkable increase in the curcumin loading capacity of acid-hydrolyzed FSG (HFSG) from 1.08 ± 0.08 µg/mg (0 h) to 9.15 ± 0.21 µg/mg (3 h). The amino acid composition indicated that acid hydrolysis effectively increased the ratio of hydrophobic amino acids of FSG. Acid hydrolysis facilitated the transformation of the α-helical conformation into a ß-sheet structure. Hydrophobic interactions between HFSG and curcumin were strengthened by moderate acid hydrolysis. A sustained-release profile emerged for the curcumin-loaded HFSG during simulated gastrointestinal digestion, thereby improving the bioaccessibility and bioavailability of curcumin. These findings contribute to the application of acid hydrolysis in modifying FSG for enhanced hydrophobicity and curcumin loading capacity in the food industry.

Chemical tools to expand the ligandable proteome: diversity-oriented synthesis-based photoreactive stereoprobes.

Chemical proteomics enables the global assessment of small molecule-protein interactions in native biological systems and has emerged as a versatile approach for ligand discovery. The range of small molecules explored by chemical proteomics has, however, been limited. Here, we describe a diversity-oriented synthesis (DOS)-inspired library of stereochemically-defined compounds bearing diazirine and alkyne units for UV light-induced covalent modification and click chemistry enrichment of interacting proteins, respectively. We find that these 'photo-stereoprobes' interact in a stereoselective manner with hundreds of proteins from various structural and functional classes in human cells and demonstrate that these interactions can form the basis for high-throughput screening-compatible nanoBRET assays. Integrated phenotypic analysis and chemical proteomics identified photo-stereoprobes that modulate autophagy by engaging the mitochondrial serine protease CLPP. Our findings show the utility of photo-stereoprobes for expanding the ligandable proteome, furnishing target engagement assays, and discovering and characterizing bioactive small molecules by cell-based screening.

Ultrasonic-enhanced photocatalysis through piezoelectric and cavitation effects for lignin depolymerization.

Although a promising method for lignin depolymerization, photocatalysis faces the challenge of low efficiency. In this study, MoS2/ZnO heterojunction catalysts, endowed with piezocatalysis and photocatalytic capabilities, were crafted through Zn ion intercalation for the depolymerization of phenoxyphenylethanol (PP-ol) and alkali lignin. Then, the synergistic interplay between ultrasonic-induced piezoelectric fields and heterojunctions was analyzed. The amalgamation of the piezoelectric field and heterojunction in MoS2/ZnO catalysts resulted in a diminished photogenerated hole/electron recombination efficiency, thereby fostering the generation of ·OH during the reaction. This pivotal role of ·OH emerged as a crucial reactive substance, converting 95.8 % of PP-ol through ß-O-4 bond breaking within a 3-h treatment. By incorporating ultrasonic, the contact probability of PP-ol with the catalyst was significantly improved, resulting in efficient conversion even with a reduced amount of acetonitrile in the solvent system (20 %). Furthermore, ultrasonic-light methods show high efficiency for depolymerizing Alkali lignin (AL), with 33.2 % of lignin undergoing depolymerization in a 4-h treatment. This treatment simultaneously reduces the molecular weight of AL and cleaves numerous chemical bonds within it. Overall, this work presents a green approach to lignin depolymerization, providing insights into the synergistic action of ultrasonic and photocatalysis.

Past dynamics and future prediction of the impacts of land use cover change and climate change on landscape ecological risk across the Mongolian plateau.

Land use/land cover (LULC) change and climate change are interconnected factors that affect the ecological environment. However, there is a lack of quantification of the impacts of LULC change and climate change on landscape ecological risk under different shared socioeconomic pathways and representative concentration pathways (SSP-RCP) on the Mongolian Plateau (MP). To fill this knowledge gap and understand the current and future challenges facing the MP's land ecological system, we conducted an evaluation and prediction of the effects of LULC change and climate change on landscape ecological risk using the landscape loss index model and random forest method, considering eight SSP-RCP coupling scenarios. Firstly, we selected MCD12Q1 as the optimal LULC product for studying landscape changes on the MP, comparing it with four other LULC products. We analyzed the diverging patterns of LULC change over the past two decades and observed significant differences between Mongolia and Inner Mongolia. The latter experienced more intense and extensive LULC change during this period, despite similar climate changes. Secondly, we assessed changes in landscape ecological risk and identified the main drivers of these changes over the past two decades using a landscape index model and random forest method. The highest-risk zone has gradually expanded, with a 30% increase compared to 2001. Lastly, we investigated different characteristics of LULC change under different scenarios by examining future LULC products simulated by the FLUS model. We also simulated the dynamics of landscape ecological risks under these scenarios and proposed an adaptive development strategy to promote sustainable development in the MP. In terms of the impact of climate change on landscape ecological risk, we found that under the same SSP scenario, increasing RCP emission concentrations significantly increased the areas with high landscape ecological risk while decreasing areas with low risk. By integrating quantitative assessments and scenario-based modeling, our study provides valuable insights for informing sustainable land management and policy decisions in the region.

Assigning functionality to cysteines by base editing of cancer dependency genes.

Covalent chemistry represents an attractive strategy for expanding the ligandability of the proteome, and chemical proteomics has revealed numerous electrophile-reactive cysteines on diverse human proteins. Determining which of these covalent binding events affect protein function, however, remains challenging. Here we describe a base-editing strategy to infer the functionality of cysteines by quantifying the impact of their missense mutation on cancer cell proliferation. The resulting atlas, which covers more than 13,800 cysteines on more than 1,750 cancer dependency proteins, confirms the essentiality of cysteines targeted by covalent drugs and, when integrated with chemical proteomic data, identifies essential, ligandable cysteines in more than 160 cancer dependency proteins. We further show that a stereoselective and site-specific ligand targeting an essential cysteine in TOE1 inhibits the nuclease activity of this protein through an apparent allosteric mechanism. Our findings thus describe a versatile method and valuable resource to prioritize the pursuit of small-molecule probes with high function-perturbing potential.

Green Extraction of Polyphenols via Deep Eutectic Solvents and Assisted Technologies from Agri-Food By-Products.

Polyphenols are the largest group of phytochemicals with important biological properties. Their presence in conveniently available low-cost sources, such as agri-food by-products, has gained considerable attention in their recovery and further exploitation. Retrieving polyphenols in a green and sustainable way is crucial. Recently, deep eutectic solvents (DESs) have been identified as a safe and environmentally benign medium capable of extracting polyphenols efficiently. This review encompasses the current knowledge and applications of DESs and assisted technologies to extract polyphenols from agri-food by-products. Particular attention has been paid to fundamental mechanisms and potential applications in the food, cosmetic, and pharmaceutical industries. In this way, DESs and DESs-assisted with advanced techniques offer promising opportunities to recover polyphenols from agri-food by-products efficiently, contributing to a circular and sustainable economy.

Insights into the Acid-Induced Gelation of Original Pectin from Potato Cell Walls by Gluconic Acid-δ-Lactone.

The acid-induced gelation of pectin in potato cell walls has been gradually recognized to be related to the improvement in the cell wall integrity after heat processing. The aim of this study was to characterize the acid-induced gelation of original pectin from a potato cell wall (OPP). Rheological analyses showed a typical solution-sol-gel transition process of OPP with different additions of gluconic acid-δ-lactone (GDL). The gelation time (Gt) of OPP was significantly shortened from 7424 s to 2286 s. The complex viscosity (η*) of OPP gradually increased after 4000 s when the pH was lower than 3.13 and increased from 0.15 to a range of 0.20~6.3 Pa·s at 9000 s. The increase in shear rate caused a decrease in η, indicating that OPP belongs to a typical non-Newtonian fluid. Furthermore, a decrease in ζ-potential (from -21.5 mV to -11.3 mV) and an increase in particle size distribution (from a nano to micro scale) was observed in OPP after gelation, as well as a more complex (fractal dimension increased from 1.78 to 1.86) and compact (cores observed by cryo-SEM became smaller and denser) structure. The crystallinity of OPP also increased from 8.61% to 26.44%~38.11% with the addition of GDL. The above results call for an investigation of the role of acid-induced OPP gelation on potato cell walls after heat processing.

Lignin-ultrasound method: Enhancement of antimicrobial capacity of MoS2-containing films.

To improve the antimicrobial ability of MoS2-containing films, we used lignin and triple-frequency ultrasound for liquid-phase exfoliation (LPE) to obtain MoS2 nanosheets. Photoresponsive antimicrobial films with MoS2 nanosheets, lignin, polyvinyl alcohol and deep eutectic solvents were subsequently prepared. Lignin functionalized the MoS2 nanosheets by chemically linking with S in MoS2 and significantly improved the exfoliation efficiency. Tri-frequency ultrasound produces beneficial effects on the LPE process by creating a more homogeneous sound field and a stronger degree of cavitation. The concentration of MoS2 nanosheets in the exfoliating solution could reach 1.713 mg/mL under the effect of lignin-ultrasound. The antimicrobial ability of the films was analyzed, and the colony-forming units of E. coli and S. aureus could be reduced from 7 × 106 to 1 × 106 cfu/mL under the irradiation of infrared. The lignin in the film undergoes depolymerization and demethoxylation under the irradiation of infrared to have a more phenolic hydroxyl structure, which confers the growth inhibition ability of the films for bacteria that cannot be in close contact with the film. The method we used has some significance for the preparation of MoS2 nanosheets, and composite films prepared from MoS2, and lignin can be used in food packaging, wound antimicrobials, and other fields.

Performance of different colorectal cancer screening strategies: a long-term passive follow-up population-based screening program in Beijing, China.

BACKGROUND: We aimed to assess the performance of the risk assessment questionnaire and fecal immunochemical test (FIT) in a population-based colorectal cancer (CRC) screening program to provide timely evidence for tailored screening strategies in China. METHODS: This analysis was conducted using data from Beijing Cancer Screening Prospective Cohort Study (BCSPCS). A risk assessment questionnaire and FIT were selected as the primary screening methods, and participants with any positive results were referred to undergo a diagnostic colonoscopy. RESULTS: From 2015 to 2020, 148,636 Beijing residents aged 40-69 years were invited from designated communities, with 147,807 finishing the risk assessment questionnaire and 115,606 (78.2%) completing the FIT. Among the 42,969 (29.1%) high-risk CRC participants, 23,824 (55.4%) underwent colonoscopy. One year after enrollment, all subjects were linked to the Beijing Cancer Registry (BCR) database and 241 cases of CRC were confirmed. The CRC incidence rate was 58.2/100,000 for the low-risk arm and 418.9/100,000 for the high-risk arm. For participants who underwent colonoscopy, 91 CRC cases were detected, with a detection rate of 91.9% and 63.7% of them were early-stage cases. Furthermore, the sensitivities of utilizing the risk assessment questionnaire alone, FIT alone, combined risk assessment questionnaire and FIT were 75.7%, 50.1%, and 95.1%, and the specificities were 75.3%, 87.3%, and 70.7%, respectively. CONCLUSION: The Beijing CRC screening program can effectively detect early-onset CRC; however, the compliance with colonoscopy still needs to be improved.

Enhancing anionic redox stability via oxygen coordination configurations.

Anionic redox in Li-rich cathode materials with disordered crystal structures has potential to increase battery energy density. However, capacity fading due to anionic redox-induced structural transformation hinders practical implementation. To address this challenge, it is crucial to understand the influence of the anion coordination structure on redox reversibility. By comprehensively studying the spinel-like Li1.7Mn1.6O3.7F0.3 and layered Li2MnO3 model systems, we found that tetrahedral oxygen exhibits higher kinetic and thermodynamic stability than octahedral oxygen in Li1.7Mn1.6O3.7F0.3 and Li2MnO3, effectively suppressing aggregation of oxidized anions. Electronic structure analysis showed that the 2p lone-pair states in tetrahedral oxygen lie deeper than those in octahedral oxygen. The Li-O-TM bond angle in a polyhedron is identified as a characteristic parameter to correlate anionic redox stability. TM substitutions using Co3+, Ti4+ and Mo5+ could effectively regulate the Li-O-Mn bond angle and anionic active electronic state. Our finding that anionic redox stability is influenced by the polyhedral structure offers new opportunities for designing high-energy-density Li-rich cathode materials.

Cultivar difference characterization of kiwifruit wines on phenolic profiles, volatiles and antioxidant activity.

Antioxidant activity and volatiles of kiwifruit wine with different flesh colors were investigated in this study. Green (Guichang and Xuxiang), red (Donghong and Hongyang), and yellow (Jinyan) kiwifruits were analyzed to determine their alcohol content, phenolic profiles, antioxidant activity, and aroma composition. The results showed that Hongyang and Donghong wines had higher antioxidant activity and content of antioxidant substances. Hongyang wine possessed the most abundance of polyphenolic compounds, chlorogenic acid and catechins were the main polyphenols of kiwi wines. The 101 aromatic components were detected, Xuxiang wine possessed 64 aromatic compounds, Donghong and Hongyang wines had the higher esters compositions, 79.87%, and 78.0% respectively. From PCA (Principal Component Analysis), the volatile substances of kiwi wine with the same flesh color were similar. Five kinds of kiwi wines shared 32 kinds of volatile compounds, these compounds may be the core volatiles in kiwi wine. Therefore, the color of kiwi flesh can impact wine flavor, with Hongyang and Donghong kiwis owning red flesh being the most suitable for producing kiwi wine which would be a new milestone to the wine manufactures.

Proteomic discovery of chemical probes that perturb protein complexes in human cells.

Most human proteins lack chemical probes, and several large-scale and generalizable small-molecule binding assays have been introduced to address this problem. How compounds discovered in such "binding-first" assays affect protein function, nonetheless, often remains unclear. Here, we describe a "function-first" proteomic strategy that uses size exclusion chromatography (SEC) to assess the global impact of electrophilic compounds on protein complexes in human cells. Integrating the SEC data with cysteine-directed activity-based protein profiling identifies changes in protein-protein interactions that are caused by site-specific liganding events, including the stereoselective engagement of cysteines in PSME1 and SF3B1 that disrupt the PA28 proteasome regulatory complex and stabilize a dynamic state of the spliceosome, respectively. Our findings thus show how multidimensional proteomic analysis of focused libraries of electrophilic compounds can expedite the discovery of chemical probes with site-specific functional effects on protein complexes in human cells.

Difference analysis of the structure and functional properties among coix seed prolamin fractions (α-, ß-, and γ-coixin).

The differences in proteins in structural characteristics are reported to affect their physicochemical and functional properties. In this study, three types of prolamins (γ-, α-, and ß-coixin) derived from coix seed separately distributed among fractions 1-3 extracts. They were studied respecting molecular weight, amino acid composition, secondary structure, microstructure, surface hydrophobicity, solubility, water holding capacity, and oil holding capacity. Results showed that the molecular weights of those three fractions were between 10 and 40 kDa. The secondary structure of those fractions was almost the same, mainly based on ß-sheet and irregular structure. The microstructure of α- and γ-coixin presented an irregular shape, whereas ß-coixin presented a regular spherical shape. Those three fractions exhibited species of abundant essential amino acids with the same amino acid composition but different contents. The ß-coixin fraction had the highest content of hydrophobic amino acids (238.39 mg/g) followed by the α-coixin fraction (235.05 mg/g), whereas the γ-coixin fraction had the lowest content (33.27 mg/g). The γ-coixin fraction has the maximum surface hydrophobicity, whereas the ß-coixin fraction has the highest solubility. In addition, the good amphiphilicity of ß-coixin fraction made it possible to be used as a surfactant. The excellent functional properties of the ß-coixin fraction presented in this research would widen the applications of coix seed prolamins. PRACTICAL APPLICATION: The molecular weights of those three fractions were between 10 and 40 kDa. The secondary structure was almost the same, mainly based on ß-sheet and irregular structure. Those three fractions exhibited species of abundant essential amino acids with the same amino acid composition but different contents. The WHC and OHC of ß-coixin were the best, indicating its potential as a surfactant and forming stable lotion.

Remodeling oncogenic transcriptomes by small molecules targeting NONO.

Much of the human proteome is involved in mRNA homeostasis, but most RNA-binding proteins lack chemical probes. Here we identify electrophilic small molecules that rapidly and stereoselectively decrease the expression of transcripts encoding the androgen receptor and its splice variants in prostate cancer cells. We show by chemical proteomics that the compounds engage C145 of the RNA-binding protein NONO. Broader profiling revealed that covalent NONO ligands suppress an array of cancer-relevant genes and impair cancer cell proliferation. Surprisingly, these effects were not observed in cells genetically disrupted for NONO, which were instead resistant to NONO ligands. Reintroduction of wild-type NONO, but not a C145S mutant, restored ligand sensitivity in NONO-disrupted cells. The ligands promoted NONO accumulation in nuclear foci and stabilized NONO-RNA interactions, supporting a trapping mechanism that may prevent compensatory action of paralog proteins PSPC1 and SFPQ. These findings show that NONO can be co-opted by covalent small molecules to suppress protumorigenic transcriptional networks.

Green and sustainable extraction of lignin by deep eutectic solvent, its antioxidant activity, and applications in the food industry.

Lignin, an amorphous biomacromolecule abundantly distributed in the plant kingdom, has gained considerable attention due to its intrinsic bioactivities and renewable nature. Owing to its polyphenolic structure, lignin has a variety of human health activities, including antioxidant, antimicrobial, antidiabetic, antitumor, and other activities. The extraction of lignin from various sources in a green and sustainable manner is critical in the food industry. Deep eutectic solvent (DES) has recently been recognized as a class of safe and environmentally friendly media capable of efficiently extracting lignin. This article comprehensively reviews the recent advances in lignin extraction using DES, discusses the influential factors on the antioxidant activity of lignin, interprets the relationship between antioxidant activity and lignin structure, and overviews the applications of lignin in the food industry. We aim to highlight the advantages of DES in lignin extraction and valorization from the nutrition and food views.

TMEM164 is an acyltransferase that forms ferroptotic C20:4 ether phospholipids.

Ferroptosis is an iron-dependent form of cell death driven by oxidation of polyunsaturated fatty acid (PUFA) phospholipids. Large-scale genetic screens have uncovered a specialized role for PUFA ether phospholipids (ePLs) in promoting ferroptosis. Understanding of the enzymes involved in PUFA-ePL production, however, remains incomplete. Here we show, using a combination of pathway mining of genetic dependency maps, AlphaFold-guided structure predictions and targeted lipidomics, that the uncharacterized transmembrane protein TMEM164-the genetic ablation of which has been shown to protect cells from ferroptosis-is a cysteine active center enzyme that selectively transfers C20:4 acyl chains from phosphatidylcholine to lyso-ePLs to produce PUFA ePLs. Genetic deletion of TMEM164 across a set of ferroptosis-sensitive cancer cell lines caused selective reductions in C20:4 ePLs with minimal effects on C20:4 diacyl PLs, and this lipid profile produced a variable range of protection from ferroptosis, supportive of an important but contextualized role for C20:4 ePLs in this form of cell death.

Exploring the mechanism of C473D mutation on CDC25B causing weak binding affinity with CDK2/CyclinA by molecular dynamics study.

CDC25B belongs to the CDC25 family, and it plays an important part in regulating the activity of CDK/CyclinA. Studies have shown that CDC25B is closely related to cancer development. When CYS473 on CDC25B is mutated into ASP, the affinity between CDC25B and CDK2/CyclinA weakens, and their dissociation speed is greatly improved. However, the mechanism by which the CDC25BC473D mutant weakens its binding to CDK2/CyclinA is unclear. In order to study the effect of CDC25BC473D mutants on CDK2/CyclinA substrates, we constructed and verified the rationality of the CDC25BWT:CDK2/CyclinA system and CDC25BC473D:CDK2/CyclinA system and conducted molecular dynamics (MD) simulation analysis. In the post-analysis, the fluctuations of residues ARG488-SER499, LYS541-TRP550 on CDC25B and residues ASP206-ASP210 on CDK2 were massive in the mutant CDC25BC473D:CDK2/CyclinA system. And the interactions between residue ARG492 and residue GLU208, residue ARG544 and residue GLU42, residue ARG544 and TRP550 were weakened in the mutant CDC25BC473D:CDK2/CyclinA system. The results showed that when CYS473 on CDC25B was mutated into ASP473, the mutant CDC25BC473D:CDK2/CyclinA system was less stable than the wild-type CDC25BWT:CDK2/CyclinA system. Finally, active site CYS473 of CDC25B was speculated to be the key residue, which had great effects on the binding between CDC25BCYS473 and CDK2 in the CDC25BC473D:CDK2/CyclinA system. Consequently, overall analyses appeared in this study ultimately provided a useful understanding of the weak interactions between CDC25BCYS473D and CDK2/CyclinA.Communicated by Ramaswamy H. Sarma.