1.Long-term survival outcomes and prognostic factors following radical resection of pancreatic body and tail cancer:a retrospective analysis of 992 patients
Dong XU ; Yang WU ; Kai ZHANG ; Nan LYU ; Qianqian WANG ; Pengfei WU ; Jie YIN ; Baobao CAI ; Guodong SHI ; Jianzhen LIN ; Yazhou WANG ; Lingdi YIN ; Zipeng LU ; Min TU ; Jianmin CHEN ; Feng GUO ; Jishu WEI ; Junli WU ; Wentao GAO ; Cuncai DAI ; Yi MIAO ; Kuirong JIANG
Chinese Journal of Surgery 2026;64(1):46-54
Objective:To investigate the survival outcomes and prognostic factors in patients undergoing radical resection for pancreatic body and tail cancer.Methods:A retrospective case series study was conducted on 992 patients who underwent radical resection for pancreatic body and tail cancer at the Pancreatic Center of the First Affiliated Hospital of Nanjing Medical University from January 2016 to June 2024. In this study, 577 (58.2%) were male and 415 (41.8%) were female,with an age of (65±9) years (range: 26 to 86 years). Follow-up continued until June 2024. Survival rates were estimated using the Kaplan-Meier method,and prognostic factors were identified using univariate and multivariate Cox proportional hazards models.Results:Among 992 patients,open surgery was the predominant approach (89.1%, 884/992), and radical antegrade modular pancreatosplenectomy (RAMPS) was performed in 317 patients (32.0%). Combined organ resection,venous resection,and arterial resection were performed in 23.5%, 9.3%,and 11.2% of patients,respectively. The rates of R0, R1-1 mm, and R1-direct resections were 49.8% (494/992),41.5% (412/992), and 8.7% (86/992),respectively. Stage ⅡB was the most common TNM stage (32.2%,319/992). A total of 801 patients (80.8%) received adjuvant chemotherapy. The median follow-up period was 32.0(8.8) months(range:3.2 to 105.3 months),during which 508 patients (51.2%) died. The overall median survival (OS) was 26.4 months,with 1-,3-, and 5-year survival rates of 79.0%,40.0%, and 29.0%, respectively. In the recent five years (from 2020 to 2024), the median OS improved significantly to 34.1 months compared to 20.0 months from 2016 to 2019 ( P<0.01). Histological subtype analysis showed that the median OS time was 26.7 months for pancreatic ductal adenocarcinoma (PDAC, n=855),58.9 months for invasive intraductal papillary mucinous carcinoma (IPMC, n=32),and 15.7 months for adenosquamous carcinoma of pancreas (ASCP, n=73) ( P=0.001). Among PDAC patients, adjuvant chemotherapy significantly improved survival (29.1 months vs. 14.4 months, P<0.01);in IPMC patients, adjuvant chemotherapy also extended survival (65.7 months vs. 58.9 months, P=0.047). Although ASCP patients receiving chemotherapy had a longer median OS time than those without (18.8 months vs. 8.9 months),the difference was not statistically significant ( P=0.151). Multivariate Cox regression analysis in PDAC patients indicated that adjuvant chemotherapy, R0 resection, T stage,N stage,and tumor differentiation were independent prognostic factors ( P<0.01). The median OS time by TNM stage was:not reached for stage ⅠA, 51.6 months for ⅠB, 25.5 months for ⅡA, 23.7 months for ⅡB, 23.0 months for Ⅲ, and 14.4 months for Ⅳ. The median OS time for R0,R1-1 mm,and R1-direct resections was 34.1,24.7,and 15.7 months,respectively ( P<0.01). Conclusion:Adjuvant chemotherapy,R0 resection,tumor stage,and differentiation are independent prognostic factors for pancreatic body and tail cancer.
2.Analysis of Clinical Prognostic Characteristics in Patients with Primary Sjögren's Syndrome-Related Renal Fanconi Syndrome
Xiaoxiao SHI ; Yuan DONG ; Jiahe JIANG ; Peng XIA ; Shuo ZHANG ; Yubing WEN ; Dong XU ; Fengchun ZHANG ; Limeng CHEN
Medical Journal of Peking Union Medical College Hospital 2026;17(2):358-369
Renal Fanconi syndrome (FS) is a rare renal manifestation of primary Sjögren's syndrome (pSS). This study aims to analyze the clinical and prognostic characteristics of patients with pSS-associated renal FS (pSS-FS) and provide insights for clinical management. Patients diagnosed with pSS-FS via renal biopsy at Peking Union Medical College Hospital from 1993 to 2024 were enrolled. Data collected included age, sex, clinical symptoms (xerostomia, xerophthalmia, skin purpura, arthralgia, polyuria, and systemic symptoms), laboratory findings [serum immunoglobulin G (IgG) and IgM, complement (C3, C4), antinuclear antibody, anti-Sjögren's syndrome-associated antigen A antibody (SSA), anti-SSB antibody, 24-hour urinary protein quantification, tubular proteinuria, serum creatinine, serum electrolytes], treatment, and follow-up information. Systematic assessments included the EULAR Sjögren's Syndrome Disease Activity Index (ESSDAI) score, pulmonary involvement (including non-infectious interstitial pneumonia, pulmonary fibrosis, pulmonary hypertension, etc.), hematological involvement (anemia, leukopenia, thrombocytopenia), etc. Efficacy evaluations encompassed improvements in immunological parameters, renal function, and tubular function. Group comparisons were performed using chi-square/Fisher's exact tests, A total of 38 patients with pSS-FS were included, with 37(97.4%) being female. The median age at pSS diagnosis was 43(37, 57) years. Xerostomia (76.3%) and xerophthalmia (71.1%) were the predominant clinical symptoms. The most common renal tubular dysfunctions were generalized aminoaciduria (96.9%), tubular proteinuria (96.0%), and hypokalemia (94.7%). The median eGFR was 52.57(32.04, 76.10)mL/(min·1.73 m2), with 60.5% (23/38) of patients having an eGFR below 60 mL/(min·1.73 m2).After six months of immunosuppressive therapy, including moderate-to-high-dose glucocorticoids, significant improvements were observed in immunological parameters (improvement rate: 69.2%), renal tubular function (89.5%), and renal function (44.4%). Following immunosuppressive treatment, the median eGFR increased from 54.95(33.06, 76.10)mL/(min·1.73 m2) to 65.56(56.24, 83.58)mL/(min·1.73 m2).Compared to patients with normal or mildly impaired baseline eGFR [≥ 60 mL/(min·1.73 m2)], those with significantly decreased baseline eGFR [< 60 mL/(min·1.73 m2)] were older (46 years This study reports the clinical characteristics of the largest single-center cohort of pSS-FS patients internationally, characterized by varying degrees of proximal renal tubular dysfunction and renal impairment. Timely initiation of immunosuppressive therapy, including glucocorticoids, is crucial, particularly for patients with significantly reduced eGFR, who may experience more substantial renal function improvement.
3.Long-term survival outcomes and prognostic factors following radical resection of pancreatic body and tail cancer:a retrospective analysis of 992 patients
Dong XU ; Yang WU ; Kai ZHANG ; Nan LYU ; Qianqian WANG ; Pengfei WU ; Jie YIN ; Baobao CAI ; Guodong SHI ; Jianzhen LIN ; Yazhou WANG ; Lingdi YIN ; Zipeng LU ; Min TU ; Jianmin CHEN ; Feng GUO ; Jishu WEI ; Junli WU ; Wentao GAO ; Cuncai DAI ; Yi MIAO ; Kuirong JIANG
Chinese Journal of Surgery 2026;64(1):46-54
Objective:To investigate the survival outcomes and prognostic factors in patients undergoing radical resection for pancreatic body and tail cancer.Methods:A retrospective case series study was conducted on 992 patients who underwent radical resection for pancreatic body and tail cancer at the Pancreatic Center of the First Affiliated Hospital of Nanjing Medical University from January 2016 to June 2024. In this study, 577 (58.2%) were male and 415 (41.8%) were female,with an age of (65±9) years (range: 26 to 86 years). Follow-up continued until June 2024. Survival rates were estimated using the Kaplan-Meier method,and prognostic factors were identified using univariate and multivariate Cox proportional hazards models.Results:Among 992 patients,open surgery was the predominant approach (89.1%, 884/992), and radical antegrade modular pancreatosplenectomy (RAMPS) was performed in 317 patients (32.0%). Combined organ resection,venous resection,and arterial resection were performed in 23.5%, 9.3%,and 11.2% of patients,respectively. The rates of R0, R1-1 mm, and R1-direct resections were 49.8% (494/992),41.5% (412/992), and 8.7% (86/992),respectively. Stage ⅡB was the most common TNM stage (32.2%,319/992). A total of 801 patients (80.8%) received adjuvant chemotherapy. The median follow-up period was 32.0(8.8) months(range:3.2 to 105.3 months),during which 508 patients (51.2%) died. The overall median survival (OS) was 26.4 months,with 1-,3-, and 5-year survival rates of 79.0%,40.0%, and 29.0%, respectively. In the recent five years (from 2020 to 2024), the median OS improved significantly to 34.1 months compared to 20.0 months from 2016 to 2019 ( P<0.01). Histological subtype analysis showed that the median OS time was 26.7 months for pancreatic ductal adenocarcinoma (PDAC, n=855),58.9 months for invasive intraductal papillary mucinous carcinoma (IPMC, n=32),and 15.7 months for adenosquamous carcinoma of pancreas (ASCP, n=73) ( P=0.001). Among PDAC patients, adjuvant chemotherapy significantly improved survival (29.1 months vs. 14.4 months, P<0.01);in IPMC patients, adjuvant chemotherapy also extended survival (65.7 months vs. 58.9 months, P=0.047). Although ASCP patients receiving chemotherapy had a longer median OS time than those without (18.8 months vs. 8.9 months),the difference was not statistically significant ( P=0.151). Multivariate Cox regression analysis in PDAC patients indicated that adjuvant chemotherapy, R0 resection, T stage,N stage,and tumor differentiation were independent prognostic factors ( P<0.01). The median OS time by TNM stage was:not reached for stage ⅠA, 51.6 months for ⅠB, 25.5 months for ⅡA, 23.7 months for ⅡB, 23.0 months for Ⅲ, and 14.4 months for Ⅳ. The median OS time for R0,R1-1 mm,and R1-direct resections was 34.1,24.7,and 15.7 months,respectively ( P<0.01). Conclusion:Adjuvant chemotherapy,R0 resection,tumor stage,and differentiation are independent prognostic factors for pancreatic body and tail cancer.
4.Construction of a biomimetic three-layered PLLA/PCL large-diameter vessel via electrospinning and ultrasonic pore-forming: Preliminary animal evaluation
Wenjun WANG ; Yang GAO ; Feng GAO ; Lei SHI ; Wei LIU ; Weiwang FAN ; Chang XU ; Hong ZHENG ; Xufeng DONG ; ZHUANG Xijing
Chinese Journal of Clinical Thoracic and Cardiovascular Surgery 2026;33(07):1093-1100
Objective To fabricate a large-diameter vascular graft with a pore size gradient structure mimicking that of natural blood vessels, using poly-L-lactic acid (PLLA) and polycaprolactone (PCL) as base materials through electrospinning and ultrasonic pore-forming techniques, and to evaluate its application potential. Methods A three-layered tubular graft was fabricated from a PCL/PLLA blend (mass ratio 6 : 4) via electrospinning, followed by an ultrasonic pore-forming process to create a gradient porosity. The resulting graft (diameter: 2 cm, length: 4 cm) was implanted into the descending thoracic aorta of an experimental pig using an end-to-end anastomosis. Graft patency and anastomotic sites were monitored by computed tomography angiography (CTA) at 1 and 6 weeks post-surgery. After 2 months, the graft was explanted for systematic evaluation of vascular regeneration and repair through gross examination, histopathology (H&E and elastic fiber staining), immunohistochemistry [for ETS-related gene (ERG), Actin, and Vimentin], and scanning electron microscopy (SEM). Results Postoperative CTA confirmed excellent graft patency at both 1 and 6 weeks, with no evidence of thrombosis or anastomotic stenosis. Gross examination of the 2-month explant revealed a smooth luminal surface covered by neotissue. Histopathological analysis demonstrated that the graft successfully induced the formation of a three-layered structure resembling a native vessel wall, comprising endothelial cells, smooth muscle cells, and fibroblasts. Immunohistochemistry further verified coverage of the luminal surface by endothelial cells (ERG-positive), along with the presence of neosmooth muscle (Actin-positive) and fibroblasts (Vimentin-positive). Endothelial cells were observed adhering to the inner surface of the artificial vessel under SEM. Conclusion The biomimetic, three-layered PLLA/PCL large-diameter vascular graft, constructed via electrospinning and ultrasonic pore-forming, exhibits excellent short-term patency and biocompatibility in a large animal model. More importantly, it demonstrates a significant potential to promote host cell infiltration and achieve in situ regeneration of a three-layered vascular wall structure, providing a promising experimental basis for the development of next-generation functional vascular substitutes.
5.A Personalized Brain-computer Interface Paradigm and Decoding Method for The Objective Evaluation of Auditory Frequency Difference Limen
Sheng-Ye LI ; Xiao-Lin XIAO ; Shi-Hang YU ; Bei-Bei ZHANG ; Xing-Wei AN ; Min-Peng XU ; Dong MING
Progress in Biochemistry and Biophysics 2026;53(7):1927-1941
ObjectiveThe frequency difference limen (FDL) serves as a fundamental metric utilized for effectively quantifying the precise perceptual capabilities of the central auditory system. However, traditional measurement methods rely heavily on the active behavioral responses of subjects and are consequently highly susceptible to the negative influence of confounding subjective factors. Furthermore, existing research paradigms frequently employ uniform stimulus configurations that overlook critical individual perceptual differences. Based on brain-computer interface (BCI) technology, this comprehensive study aims to establish an objective and quantitative evaluation method for auditory frequency discrimination by systematically analyzing and decoding the specific neural responses elicited at the exact threshold state. MethodsWe designed a personalized rapid serial auditory presentation (RSAP) paradigm customized based on each individual’s precise FDL. A cohort of eleven healthy participants was recruited to evaluate the paradigm using pure-tone sequences at a baseline frequency of 4 000 Hz. This experimental paradigm simulates a realistic auditory perception environment through the continuous presentation of acoustic stimuli, thereby allowing for an in-depth investigation into the specific neural representations evoked by weak frequency deviations at the threshold state. Given that auditory stimulus-evoked response features exhibit complex and differentiated spatiotemporal distribution patterns across multiple frequency domains, this study further deeply integrates the cross-scale feature interaction module with the dynamic spatiotemporal attention allocation strategy, innovatively proposing the Multi-Scale Spatial-Temporal Dual Attention Network (MS-STAMNet). Specifically, the network constructs parallel processing branches with multiple receptive fields and introduces a dynamic adaptive weighting strategy to precisely localize core neural activity signals, further deeply integrating multi-scale information through cross-branch feature information interaction to achieve robust single-trial decoding of weak auditory evoked responses. ResultsThe comprehensive electrophysiological data analysis demonstrated that subtle auditory frequency deviation stimuli presented at the threshold level successfully elicited pronounced N2 and P3 event-related potential features, reflecting pre-attentive mismatch detection and subsequent cognitive evaluation, which were prominently distributed over the frontal, central, and temporal regions of the scalp. In the complex time-frequency domain, the extracted neural response characteristics exhibited distinct, statistically significant event-related synchronization within both the low-frequency δ and θ frequency bands, which was simultaneously accompanied by a widespread, prominent event-related desynchronization within the higher α band. A comparative analysis of model performance demonstrated that MS-STAMNet achieved an average unweighted average recall (UAR) of (69.67±6.12)% and area under the curve (AUC) of 0.761 8±0.07, significantly outperforming the established baseline models such as EEGNet and PLNet. Furthermore, a distinct dissociation phenomenon was verified between neural decoding and behavioral performance through regression analysis (R2=0.016, P=0.709), indicating that this model can effectively capture the implicit features of subtle frequency deviations, even when they fail to trigger explicit conscious responses. Additionally, attention weight visualization analysis further reveals the highly accurate focus of the network on key features concentrated over the bilateral temporal and fronto-parietal regions. ConclusionThis study systematically and comprehensively uncovers the multi-dimensional spatiotemporal evolutionary patterns of complex neural responses processing subtle acoustic variations under long-sequence threshold auditory stimulation. Concurrently, it verifies the efficacy and robustness of the proposed MS-STAMNet architecture in accurately deciphering weak, single-trial electroencephalogram signals amidst complex background noise. Ultimately, these neurophysiological and algorithmic findings lay a solid theoretical and methodological foundation for the objective and quantitative evaluation of individual auditory cognitive capabilities in clinical applications, transcending the fundamental limitations of traditional behavioral paradigms and providing robust technical support for future auditory research and related clinical assessments.
6.The Role of Impulsivity in Cognitive Impairment in Manic Episodes of Bipolar Ⅰ Disorder
Jie LI ; Mi-liang SHI ; Gen-xiang PEI ; Xu-dong LI ; Ai-hong ZHANG
Progress in Modern Biomedicine 2025;25(15):2511-2516,2529
Objective:To observe the role of impulsivity in cognitive impairment in manic episodes of bipolar Ⅰ disorder(BPDTI)patients.Methods:180 cases of patients with BPDTI manic episodes admitted to our hospital from February 2024 to December 2024 were selected as the manic group,and another 180 cases of volunteers who were psychologically tested as normal during the same period were selected as the healthy group.The impulse Barratt-11 scale(BIS-11)and the MATRICS Consensus Cognitive Test(MCCB)were used to investigate and evaluate impulsivity and cognitive function,and correlation analysis and risk factor analysis were conducted.Results:In the BIS-11 scale,there was no statistically significant difference between the two groups in the unplanned factor(P>0.05),but there were significant differences compared between the two groups in cognitive,motor factors,and total score(P<0.05).The MCCB scores of the manic group in information processing speed,working memory,word learning,visual learning,social cognition,reasoning and problem solving,and attention vigilance were significantly lower than those of the healthy group(P<0.05).The relationship between BIS-11 total score and cognitive impulsivity factor and MCCB total score and word learning showed there were negative correlation(P<0.05);The exercise factor in the BIS-11 scale were negatively correlated with the MCCB total score and working memory factor(P<0.05);The unplanned factor in the BIS-11 scale showed there were negative correlation with the MCCB total score,word learning(P<0.05),and information processing speed.BIS-11,the number of years of education was an influencing factor for BPDTI mania(P<0.05).Conclusion:BPDTI mania patients had high impulsivity and cognitive impairment,high impulsivity and number of years of education were influencing factors for mania,high impulsivity affected cognitive function through corresponding brain regions,aggravating the condition.
7.circHERC4_041 Inhibits the Fibrotic Phenotype of Cardiac Fibroblasts by Encoding Protein
Yuan GAO ; Chuan-Meng ZHOU ; Hua-Yan WU ; Ya WANG ; Ru-Shi WU ; Pei-Ying GUAN ; Jun-Tao FANG ; Jin-Dong XU ; Yu-Peng LIU ; Zhi-Qin HU ; Zhi-Xin SHAN
Chinese Journal of Biochemistry and Molecular Biology 2025;41(3):393-403
A mounting body of research suggests that circRNAs significantly contribute to the develop-ment of myocardial fibrosis.The microarray results of human circular RNA expression profile indicated that circHERC4_041 expression increased in the myocardium of patients with heart failure,RT-qPCR a-nalysis confirmed that the myocardial expression level of circHERC4_041 in individuals with heart failure were considerably elevated compared to that in healthy organ donors.Fluorescence in situ hybridization(FISH)confirmed that circHERC4_041 was abundant in the cytoplasm of human cardiomyocyte AC16.Overexpression of circHERC4_041 in mouse myocardial fibroblasts(mCFs)mediated by adenovirus in-hibited the expression of fibrosis-related proteins in mCFs.Experiments involving cell proliferation,wound healing,and Transwell assays demonstrated that overexpression of circHERC4_041 suppressed the growth and mobility of mCFs(P<0.001).Sequence analysis results suggested that circHERC4_041 con-tains potential ribosome entry sequence(IRES)and open reading frame(ORF).Western blot confirmed that circHERC4_041 could translate the 516 amino acid HERC4-516aa protein,which was mainly located in the cytoplasm of the cell.Cell functional experiments confirmed that circHERC4_041 inhibited the fi-brotic phenotype of mCFs by specifically translating HERC4-516aa(P<0.05).The specific interaction between HERC4-516aa and transglutaminase 2(TGM2)was confirmed by IP-MS screening and Co-IP i-dentification.Further results found that the degradation of TGM2 was promoted through proteasome path-way.The overexpression of TGM2 in mCFs facilitated by adenoviral vectors could counteract the suppres-sive effects of HERC4-516aa on the fibrotic phenotype of mCFs.Therefore,this study confirmed that the HERC4-516aa protein translated by circHERC4_041 can specifically bind to TGM2 to inhibit the fibrotic phenotype of myocardial fibroblasts.
8.Risk prediction mode of breast cancer in patients with pathological nipple discharge based on decision tree method
Guang-dong SHAO ; Ming-ming SHI ; Yi-ning SONG ; Chun-hong XU ; Xiao-dong MA ; Xiao-liang HAO
Chinese Journal of Current Advances in General Surgery 2025;28(3):175-179
Objective:To construct a decision tree model to predict the risk of breast cancer in patients with pathological nipple discharge.Methods:A total of 157 patients with pathological nipple discharge,who were diagnosed and treated at Weifang Municipal Hospital of Traditional Chinese Medicine from January 2019 to April 2024 and met the inclusion criteria,were selected.A risk prediction model for concurrent breast cancer in patients with pathological nipple discharge was developed using Logistic regression analysis.A decision tree was then constructed,and the predictive performance of the model was assessed based on the area under the receiver operating characteristic curve(AUC).Re-sults:The incidence of concurrent breast cancer among patients with pathological nipple discharge was 24.2%.Accord-ing to the results of binary Logistic regression analysis,elevated CEA and CA 153 levels in nipple discharge,as well as bloody discharge,emerged as independent risk factors for the development of breast cancer in such patients(P<0.05).Based on these findings,a decision tree model was constructed to predict the risk of concurrent breast cancer in patients with pathological nipple discharge.The validation results showed that the Logistic regression model had an AUC value of 0.800,while the decision tree model achieved an AUC value of 0.889.Conclusions:The decision tree model,built upon the identified influencing factors,exhibits strong predictive power for the risk of developing concurrent breast can-cer in patients with pathological nipple discharge,thus facilitating more precise preoperative diagnoses by clinicians for these patients.
9.Comparison of chemical constituents in traditional decoction and formula granule decoction of Wendan Decoction
Tan XUE ; Man-wen XU ; Xue-hua FAN ; Feng-yu DONG ; Yan MIAO ; Jia-ning SUN ; Jun-han SHI ; Lu ZHANG ; Jing YAO ; Rui-xin LIU
Chinese Traditional Patent Medicine 2025;47(2):384-394
AIM To compare the chemical constituents in traditional decoction and formula granule decoction of classical famous prescription Wendan Decoction.METHODS The HPLC fingerprints were established,after which the contents of adenosine,synephrine,liquiritin,naringin,hesperidin,6-gingerol and adenosine cyclophosphate were determined,cluster analysis,principal component analysis and multidimensional scaling analysis were adopted in the investigation of component differences,and the equivalent of formula granules was adjusted.RESULTS The similarities of HPLC fingerprints for 10 batches of traditional decoctions were higher than those of HPLC fingerprints for 9 batches of formula granule decoctions(P<0.01).Adenosine,synephrine,liquiritin,hesperidin and cyclic adenosine monophosphate demonstrated higher contents in traditional decoctions than those in formula granule decoctions(P<0.05),6-gingerol displayed lower content than that in the latter produced by manufacturers A,C(P<0.05),which was higher than that in the latter produced by manufacturer B(P<0.01).Various batches of traditional decoctions and formula granule decoctions could be obviously distinguished,adenosine,synephrine and hesperidin exhibited great influences on the classification of principal component analysis,and the quality of formula granule decoctions produced by manufacturer C was closer to that of traditional decoctions.After equivalent correction,the contents of various constituents in formula granule decoctions produced by manufacturers A,C showed no significant differences as compared with those in traditional decoction(P>0.05).CONCLUSION The formula granules of Wendan Decoction from different manufacturers exist quality differences,so the preparation process and extraction process of this preparation should be optimized to improve quality,and equivalent ratio should be adjusted according to actual requirements to ensure its scientific and rational clinical application.
10.Novel Structural Features of Isoflavone Synthase from Medicago truncatula Shed Light on Its Unique Enzymatic Mechanism
Chao SHI ; Zhao-Yang YE ; Fei XU ; Xiang-Ning DU ; Zhang-Xin CHEN ; Ming-Yue GU ; Jie DENG ; Wei WANG ; Liang-Yu LIU ; Mei-Ying WANG ; Xiao-Dong SU ; He-Li LIU ; Ming-Ying SHANG ; Li-Xin HUANG ; Zhen-Zhan CHANG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(8):1204-1213,中插1-中插6
Isoflavones which mainly distributed in leguminous plants have plenty of health benefits.Isoflavone synthase(IFS)is a membrane-associated cytochrome P450 enzyme(CYP450)which carries out the unique aryl-ring migration and hydroxylation.So far,few crystal structures of plant P450s have been obtained.We determined the crystal structure of IFS from Medicago truncatula at 1.9 ? by MAD method using a selenomethionine substituted crystal and conducted molecular docking and mutagenesis study.The structure of IFS complexed with imidazole exhibits the helix Ⅰa-loop-helix Ⅰβ motif which cor-responds to helix Ⅰ of other P450s.Compared with structures of common P450s,IFS/imidazole structure contains an extra domain,i.e.,the γ-domain.The structure reveals a homodimer in which the γ-domain of one molecule interacts with the β-domain of another.The plane of heme group makes an angle of ap-proximately 40° with the helix Ⅰa-loop-helix Ⅰβ motif.Molecular docking combined with mutagenesis study suggested that Trp-128 and Asp-300 might play important roles in substrate binding and recogni-tion.Phe-301,Ser-303 and Gly-305 from the helix Ⅰa-loop-helix Ⅰβ motif may play important roles in the aryl-ring migration.These novel structural features reveal insights into the unique reaction mechanism of IFS and provide a basis for engineering IFS in leguminous crops for health purpose.

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