1.Plasma miRNA testing in the differential diagnosis of very early-stage hepatocellular carcinoma: a multicenter real-world study
Jie HU ; Ying XU ; Ao HUANG ; Lei YU ; Zheng WANG ; Xiaoying WANG ; Xinrong YANG ; Zhenbin DING ; Qinghai YE ; Yinghong SHI ; Shuangjian QIU ; Huichuan SUN ; Qiang GAO ; Jia FAN ; Jian ZHOU
Chinese Journal of Clinical Medicine 2025;32(3):350-354
Objective To explore the application of plasma 7 microRNA (miR7) testing in the differential diagnosis of very early-stage hepatocellular carcinoma (HCC). Methods This study is a multicenter real-world study. Patients with single hepatic lesion (maximum diameter≤2 cm) who underwent plasma miR7 testing at Zhongshan Hospital, Fudan University, Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Anhui Provincial Hospital, and Peking University People’s Hospital between January 2019 and December 2024 were retrospectively enrolled. Patients were divided into very early-stage HCC group and non-HCC group, and the clinical pathological characteristics of the two groups were compared. The value of plasma miR7 levels, alpha-fetoprotein (AFP), and des-gamma-carboxy prothrombin (DCP) in the differential diagnosis of very early-stage HCC was evaluated using receiver operating characteristic (ROC) curves and area under the curve (AUC). In patients with both negative AFP and DCP (AFP<20 ng/mL, DCP<40 mAU/mL), the diagnostic value of plasma miR7 for very early-stage HCC was analyzed. Results A total of 64 528 patients from 4 hospitals underwent miR7 testing, and 1 682 were finally included, of which 1 073 were diagnosed with very early-stage HCC and 609 were diagnosed with non-HCC. The positive rate of miR7 in HCC patients was significantly higher than that in non-HCC patients (67.9% vs 24.3%, P<0.001). ROC curves showed that the AUCs for miR7, AFP, and DCP in distinguishing HCC patients from the non-HCC individuals were 0.718, 0.682, and 0.642, respectively. The sensitivities were 67.85%, 43.71%, and 44.45%, and the specificities were 75.70%, 92.78%, and 83.91%, respectively. The pairwise comparison of AUCs showed that the diagnostic efficacy of plasma miR7 detection was significantly better than that of AFP or DCP (P<0.05). Although its specificity was slightly lower than AFP and DCP, the sensitivity was significantly higher. Among patients negative for both AFP and DCP, miR7 maintained an AUC of 0.728 for diagnosing very early-stage HCC, with 67.82% sensitivity and 77.73% specificity. Conclusions Plasma miR7 testing is a potential molecular marker with high sensitivity and specificity for the differential diagnosis of small hepatic nodules. In patients with very early-stage HCC lacking effective molecular markers (negative for both AFP and DCP), miR7 can serve as a novel and effective molecular marker to assist diagnosis.
2.Effect of Different Time Interventions of Yangxin Tongmai Formula (养心通脉方) on DNA Methylation in Rat Models of Premature Coronary Heart Disease with Blood Stasis Syndrome
Xing CHEN ; Zixuan YU ; Shumeng ZHANG ; Yanjuan LIU ; Shuangyou DENG ; Ying WANG ; Lingli CHEN ; Jie LI
Journal of Traditional Chinese Medicine 2025;66(11):1165-1173
ObjectiveTo observe the effect of Yangxin Tongmai Formula (养心通脉方) by midnight-noon ebb-flow administration method for rat models of premature coronary heart disease (PCHD) with blood stasis syndrome, and to explore the possible mechanism of action from the perspective of DNA methylation differential gene expression. MethodsThere were 3 SD rats in each of the blank group, model group and Yangxin Tongmai Formula group, and the rats in the model group and Yangxin Tongmai Formula group were fed with high-fat chow plus vitamin D3 by gavage plus isoproterenol hydrochloride by subcutaneous injection to construct rat models of PCHD with blood stasis syndrome. After successful modelling, rats in Yangxin Tongmai Formula group were gavaged with 18 g/(kg‧d) of Yangxin Tongmai Formula, and rats in blank group and the model group were gavaged with 4 ml/(kg‧d) of 0.9% NaCl solution, and serum samples of rats in each group were collected for DNA methylation sequencing after 3 weeks to screen for the relevant DNA methylation differentiation genes. In addition, rats with successful modelling of PCHD with blood stasis were randomly divided into model group, Yangxin Tongmai Formula with midnight-noon ebb-flow administration method group [18 g/(kg‧d) of Yangxin Tongmai Formula was gavaged twice in the heart channel period (12:00) and pericardium channel period (20:00)], the Yangxin Tongmai Formula control group [18 g/(kg‧d) of Yangxin Tongmai Formula was gavaged twice at 8:00 and 18:00] and the Atorvastatin Calcium group [atorvastatin calcium tablets solution 1.8 mg/(kg‧d) at the same intervention time as that in Yangxin Tongmai Formula control group], and set up a blank group of 8 rats in each group. The model group and blank group were gavaged with 0.9% NaCl solution 4 ml/(kg‧d) for the same time as the Yangxin Tongmai Formula control group. After 3 weeks of gavage, the blood lipids [including total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL)] levels of rats in each group were detected; the HE staining of myocardial tissues and thoracic aorta was used to observe the pathomorphological changes; the levels of serum inflammation indexes [tumour necrosis factor alpha (TNF-alpha), lipopolysaccharide (LPS), and interleukin 10 (IL-10)] were detected; immunoprecipitation-realtime fluorescence quantitative PCR was used to detect the relative expression of cardiac tissue screening differential genes. ResultsThe genes screened for differentially methylated regions were calmodulin 2 (Calm2), calcium voltage-gated channel subunit α1s (Cacna1s), and phospholipase Cβ1 (Plcb1). Compared with the blank group, rats in the model group showed elevated levels of TC, LDL, TNF-α and LPS, and decreased levels of HDL and IL-10 (P<0.05 or P<0.01); HE staining showed obvious swelling of myocardial fibres, accompanied by a large number of inflammatory cell infiltration, and thickening of the inner wall of the aortic vessels with internal wall damage, which was visible as a large number of lipid cholesterol crystals and obvious inflammatory cell infiltration. Compared with the model group, the TC, LDL, TNF-α and LPS contents of rats in the Yangxin Tongmai Formula with midnight-noon ebb-flow administration method group, the Yangxin Tongmai Formula control group, and the atorvastatin calcium group all reduced, and the contents of HDL and IL-10 all elevated (P<0.05), with the improvement of myocardial tissue damage and the reduction of inflammatory infiltration, and the improvement of the damage of the inner lining of the thoracic aorta and the reduction of lipid infiltration. Compared with Yangxin Tongmai Formula control group, LDL, TNF-α and LPS contents reduced, and IL-10 contents increased in the midnight-noon ebb-flow administration method group (P<0.05). Compared with the model group, the relative expression of Calm2 and Plcb1 genes decreased and the relative expression of Cacna1s gene increased in Yangxin Tongmai Formula control group and the midnight-noon ebb-flow administration method group (P<0.05); compared with the Yangxin Tongmai Formula control group, the relative expression of Calm2 gene decreased and the relative expression of Cacna1s gene increased in the midnight-noon ebb-flow administration method group (P<0.05). ConclusionThe intervention of Yangxin Tongmai Formula in the heart channel period (12:00) and pericardium channel period (20:00) was more effective in improving the blood lipid level, inhibiting inflammation, and improving myocardial tissue damage in rats of PCHD with blood stasis syndrome, and Calm2 and Cacna1s genes may be the key targets of Yangxin Tongmai Formula in intervening the blood stasis syndrome of PCHD.
3.A Sensitive Lateral Flow Immunoassay for Detection of Interleukin-6 Using Carbon Dots-Mesoporous Silica Nanocomposite Fluorescent Probes
Yue-Qian YANG ; Peng-Yue WANG ; Jia-Qi REN ; Xiao PAN ; Feng-Hua TAN ; Yu-Jie MA ; Cong-Ying WEN ; Jing-Bin ZENG
Chinese Journal of Analytical Chemistry 2025;53(9):1467-1475
In this study,a sensitive lateral flow immunoassay(LFIA)platform based on carbon dots-mesoporous silica nanocomposite(CD-MSNs)fluorescent probes was constructed for high-performance detection of inflammatory marker interleukin-6(IL-6).Green fluorescent carbon dots(CDs)were prepared by hydrothermal method with 3,9-perylenic acid and 3-aminopropyltriethoxysilane(APTES)as raw materials,and highly fluorescent CD-MSNs composites were then constructed by encapsulating the prepared CDs in mesoporous silica nanoparticles(MSNs).Fluorescent probes were prepared by covalent coupling of CD-MSNs with IL-6 antibody.Fluorescent immunochromatographic test strips were constructed by spraying IL-6 capture antibody and goat anti-mouse IgG on nitrocellulose membrane as detection line(T-line)and quality control line(C-line),respectively.The fluorescence immunoassay analyzer was used to quantitatively detect the fluorescence intensity of T-line,and the experimental results showed that the LFIA platform based on this probe had a good linear relationship in IL-6 concentration range of 102-106 pg/mL,and the detection limit was 64 pg/mL,which was two orders of magnitude more sensitive than that of the traditional colloidal gold test strips.This method effectively solved the issue of insufficient sensitivity of traditional LFIA technique,and provided a rapid and highly sensitive detection method for early diagnosis of inflammatory diseases.
4.Carvedilol to prevent hepatic decompensation of cirrhosis in patients with clinically significant portal hypertension stratified by new non-invasive model (CHESS2306)
Chuan LIU ; Hong YOU ; Qing-Lei ZENG ; Yu Jun WONG ; Bingqiong WANG ; Ivica GRGUREVIC ; Chenghai LIU ; Hyung Joon YIM ; Wei GOU ; Bingtian DONG ; Shenghong JU ; Yanan GUO ; Qian YU ; Masashi HIROOKA ; Hirayuki ENOMOTO ; Amr Shaaban HANAFY ; Zhujun CAO ; Xiemin DONG ; Jing LV ; Tae Hyung KIM ; Yohei KOIZUMI ; Yoichi HIASA ; Takashi NISHIMURA ; Hiroko IIJIMA ; Chuanjun XU ; Erhei DAI ; Xiaoling LAN ; Changxiang LAI ; Shirong LIU ; Fang WANG ; Ying GUO ; Jiaojian LV ; Liting ZHANG ; Yuqing WANG ; Qing XIE ; Chuxiao SHAO ; Zhensheng LIU ; Federico RAVAIOLI ; Antonio COLECCHIA ; Jie LI ; Gao-Jun TENG ; Xiaolong QI
Clinical and Molecular Hepatology 2025;31(1):105-118
Background:
s/Aims: Non-invasive models stratifying clinically significant portal hypertension (CSPH) are limited. Herein, we developed a new non-invasive model for predicting CSPH in patients with compensated cirrhosis and investigated whether carvedilol can prevent hepatic decompensation in patients with high-risk CSPH stratified using the new model.
Methods:
Non-invasive risk factors of CSPH were identified via systematic review and meta-analysis of studies involving patients with hepatic venous pressure gradient (HVPG). A new non-invasive model was validated for various performance aspects in three cohorts, i.e., a multicenter HVPG cohort, a follow-up cohort, and a carvediloltreating cohort.
Results:
In the meta-analysis with six studies (n=819), liver stiffness measurement and platelet count were identified as independent risk factors for CSPH and were used to develop the new “CSPH risk” model. In the HVPG cohort (n=151), the new model accurately predicted CSPH with cutoff values of 0 and –0.68 for ruling in and out CSPH, respectively. In the follow-up cohort (n=1,102), the cumulative incidences of decompensation events significantly differed using the cutoff values of <–0.68 (low-risk), –0.68 to 0 (medium-risk), and >0 (high-risk). In the carvediloltreated cohort, patients with high-risk CSPH treated with carvedilol (n=81) had lower rates of decompensation events than non-selective beta-blockers untreated patients with high-risk CSPH (n=613 before propensity score matching [PSM], n=162 after PSM).
Conclusions
Treatment with carvedilol significantly reduces the risk of hepatic decompensation in patients with high-risk CSPH stratified by the new model.
5.Carvedilol to prevent hepatic decompensation of cirrhosis in patients with clinically significant portal hypertension stratified by new non-invasive model (CHESS2306)
Chuan LIU ; Hong YOU ; Qing-Lei ZENG ; Yu Jun WONG ; Bingqiong WANG ; Ivica GRGUREVIC ; Chenghai LIU ; Hyung Joon YIM ; Wei GOU ; Bingtian DONG ; Shenghong JU ; Yanan GUO ; Qian YU ; Masashi HIROOKA ; Hirayuki ENOMOTO ; Amr Shaaban HANAFY ; Zhujun CAO ; Xiemin DONG ; Jing LV ; Tae Hyung KIM ; Yohei KOIZUMI ; Yoichi HIASA ; Takashi NISHIMURA ; Hiroko IIJIMA ; Chuanjun XU ; Erhei DAI ; Xiaoling LAN ; Changxiang LAI ; Shirong LIU ; Fang WANG ; Ying GUO ; Jiaojian LV ; Liting ZHANG ; Yuqing WANG ; Qing XIE ; Chuxiao SHAO ; Zhensheng LIU ; Federico RAVAIOLI ; Antonio COLECCHIA ; Jie LI ; Gao-Jun TENG ; Xiaolong QI
Clinical and Molecular Hepatology 2025;31(1):105-118
Background:
s/Aims: Non-invasive models stratifying clinically significant portal hypertension (CSPH) are limited. Herein, we developed a new non-invasive model for predicting CSPH in patients with compensated cirrhosis and investigated whether carvedilol can prevent hepatic decompensation in patients with high-risk CSPH stratified using the new model.
Methods:
Non-invasive risk factors of CSPH were identified via systematic review and meta-analysis of studies involving patients with hepatic venous pressure gradient (HVPG). A new non-invasive model was validated for various performance aspects in three cohorts, i.e., a multicenter HVPG cohort, a follow-up cohort, and a carvediloltreating cohort.
Results:
In the meta-analysis with six studies (n=819), liver stiffness measurement and platelet count were identified as independent risk factors for CSPH and were used to develop the new “CSPH risk” model. In the HVPG cohort (n=151), the new model accurately predicted CSPH with cutoff values of 0 and –0.68 for ruling in and out CSPH, respectively. In the follow-up cohort (n=1,102), the cumulative incidences of decompensation events significantly differed using the cutoff values of <–0.68 (low-risk), –0.68 to 0 (medium-risk), and >0 (high-risk). In the carvediloltreated cohort, patients with high-risk CSPH treated with carvedilol (n=81) had lower rates of decompensation events than non-selective beta-blockers untreated patients with high-risk CSPH (n=613 before propensity score matching [PSM], n=162 after PSM).
Conclusions
Treatment with carvedilol significantly reduces the risk of hepatic decompensation in patients with high-risk CSPH stratified by the new model.
6.Carvedilol to prevent hepatic decompensation of cirrhosis in patients with clinically significant portal hypertension stratified by new non-invasive model (CHESS2306)
Chuan LIU ; Hong YOU ; Qing-Lei ZENG ; Yu Jun WONG ; Bingqiong WANG ; Ivica GRGUREVIC ; Chenghai LIU ; Hyung Joon YIM ; Wei GOU ; Bingtian DONG ; Shenghong JU ; Yanan GUO ; Qian YU ; Masashi HIROOKA ; Hirayuki ENOMOTO ; Amr Shaaban HANAFY ; Zhujun CAO ; Xiemin DONG ; Jing LV ; Tae Hyung KIM ; Yohei KOIZUMI ; Yoichi HIASA ; Takashi NISHIMURA ; Hiroko IIJIMA ; Chuanjun XU ; Erhei DAI ; Xiaoling LAN ; Changxiang LAI ; Shirong LIU ; Fang WANG ; Ying GUO ; Jiaojian LV ; Liting ZHANG ; Yuqing WANG ; Qing XIE ; Chuxiao SHAO ; Zhensheng LIU ; Federico RAVAIOLI ; Antonio COLECCHIA ; Jie LI ; Gao-Jun TENG ; Xiaolong QI
Clinical and Molecular Hepatology 2025;31(1):105-118
Background:
s/Aims: Non-invasive models stratifying clinically significant portal hypertension (CSPH) are limited. Herein, we developed a new non-invasive model for predicting CSPH in patients with compensated cirrhosis and investigated whether carvedilol can prevent hepatic decompensation in patients with high-risk CSPH stratified using the new model.
Methods:
Non-invasive risk factors of CSPH were identified via systematic review and meta-analysis of studies involving patients with hepatic venous pressure gradient (HVPG). A new non-invasive model was validated for various performance aspects in three cohorts, i.e., a multicenter HVPG cohort, a follow-up cohort, and a carvediloltreating cohort.
Results:
In the meta-analysis with six studies (n=819), liver stiffness measurement and platelet count were identified as independent risk factors for CSPH and were used to develop the new “CSPH risk” model. In the HVPG cohort (n=151), the new model accurately predicted CSPH with cutoff values of 0 and –0.68 for ruling in and out CSPH, respectively. In the follow-up cohort (n=1,102), the cumulative incidences of decompensation events significantly differed using the cutoff values of <–0.68 (low-risk), –0.68 to 0 (medium-risk), and >0 (high-risk). In the carvediloltreated cohort, patients with high-risk CSPH treated with carvedilol (n=81) had lower rates of decompensation events than non-selective beta-blockers untreated patients with high-risk CSPH (n=613 before propensity score matching [PSM], n=162 after PSM).
Conclusions
Treatment with carvedilol significantly reduces the risk of hepatic decompensation in patients with high-risk CSPH stratified by the new model.
7.Atomic force microscopic observation of surface structure of purified protein molecules in vitro
Zhao-ying CHEN ; Xiao-feng FANG ; Dan-yan LIU ; Meng-qin CHEN ; Xi LING ; Jie-min ZHAO ; Wei WEI ; Yu-jing WU
Chinese Pharmacological Bulletin 2025;41(1):193-199
Aim To compare the observation results of atomic force microscopy(AFM)and scanning electron microscopy(SEM),and to summarize the main problems and solutions of AFM in observing biological macromolecules,using the observa-tion subjects of protein samples purified by our research group.Methods The protein samples were diluted to 15 nmol·L-1 with PBS,fixed on glass slides,silicon wafers,and mica sheets,dried,and made into solid-phase observation samples.SEM sam-ples were plated with platinum before observation.The surface structures of proteins were observed using AFM and SEM,sample heights were calculated,and differences in results were com-pared.Results Protein samples with positive charges tended to shift to the right during observation due to the repulsion of the AFM probe;mica sheets could effectively eliminate the positive charge of proteins to avoid sample movement;PBS provided a stable environment for protein samples,but the crystallization of PBS salts interfered with probe operation and imaging clarity;SEM samples needed to be plated with platinum before observa-tion and could not achieve the precision of AFM.Conclusions Both AFM and SEM can directly observe protein structures in vitro,with AFM providing higher precision results;when protein sample stability permits,ultrapure water is preferred as the sol-vent carrier,and volatile liquids such as ethanol can also serve as solvent carriers.The application of AFM offers a new approach for pharmacological studies on interactions between biological macromolecules.
8.Survival and cause-of-death analysis of 55 thousand thyroid cancer cases in China from a large single institution hospital-based cancer registry database
Jie SHEN ; Wanlin LIU ; Zezhou WANG ; Sibo MU ; Miao MO ; Changming ZHOU ; Jing YUAN ; Yu WANG ; Ying ZHENG ; Qinghai JI
China Oncology 2025;35(1):68-76
Background and purpose:Thyroid cancer is the most common malignant endocrine tumor,particularly prevalent among the Asian population.The overall survival for thyroid cancer patients is relatively high,but there are significant survival differences among patients.Based on long-term hospital-based cancer registry database,this study analyzed the 10-year observed overall survival(OS)rate of thyroid cancer cases and the distribution of causes of death,providing real-world evidences to further survival management of thyroid cancer in China.Methods:A total of 55343 thyroid cancer patients who underwent treatment at Fudan University Shanghai Cancer center from 2005 to 2021 were included in this study.Clinical information and the follow-up endpoint data were collected through medical records review,telephone visits and death registry data linkage.The last follow-up date was October 31,2024.Kaplan-Meier method was applied in evaluating the OS rate,and survival data were described by different subgroups as age group,gender,treatment period,tumor staging and pathological characteristics.The standardized mortality ratio(SMR)and absolute excess risk(AER)were calculated using general Shanghai population as the reference,and the mortality risk was described by gender,age at diagnosis and histological subtype.Results:With a median follow-up time of 63.01 months,the overall 1-,3-,5-and 10-year OS rates of thyroid cancer patients were 99.67%(95%CI:99.62%-99.72%),99.11%(95%CI:99.03%-99.19%),98.48%(95%CI:98.36%-98.60%)and 95.81%(95%CI:95.50%-96.11%),respectively.The 10-year OS rates of stage Ⅰ,Ⅱ,Ⅲ and Ⅳ were 97.99%(95%CI:97.70%-98.28%),89.80%(95%CI:87.24%-92.37%),77.84%(95%CI:70.76%-84.92%)and 62.95%(95%CI:55.37%-70.54%),respectively.The differences in OS among patients with different age,gender and histological classification were significant.1256(2.27%)deaths occurred,of which 18.63%,50.88%and 7.32%were attributable to thyroid cancer,other cancers and cardiovascular disease(CVD),respectively.Compared with the general population,patients with different subtypes of thyroid cancer had higher all-cause mortality rates,progressively increasing with papillary,follicular,medullary and anaplastic thyroid carcinoma/poorly differentiated carcinoma.Compared with general population,the death risk was 2.24 times higher in papillary thyroid cancer patients(95%CI:2.06-2.44),9.94 times higher in follicular thyroid cancer patients(95%CI:6.79-14.09),12.16 times higher in medullary thyroid cancer patients(95%CI:8.05-17.69),and the highest risk was observed in patients with anaplastic thyroid carcinoma/poorly differentiated carcinoma[SMR=79.67(95%CI:58.38-106.31),AER=766.01/1 000 person-years].Conclusion:The 10-year long survival data and cause of death for thyroid cancer patients with different histological types were reported in China based on a large single institution hospital-based cancer registry database.Staging and histological characteristics were the most important factors directly affected the survival.Early diagnosis and individualized treatment are crucial for improving prognosis.
9.Early Efficacy of Intense Pulsed Light Combined with Non-Ablative Fractional Laser in Preventing Postoperative Pathological Scar Formation and Intervention of Inflammatory Factors
Li-min TIAN ; Yan-qin YU ; Yang ZHANG ; Xin-ying YANG ; Meng-jie WANG ; Ya-gaer TU ; Hao-dong CHEN ; Yue-nan YANG
Progress in Modern Biomedicine 2025;25(13):2181-2187
Objective:To observe the early efficacy of intense pulsed light(IPL)combined with non-ablative fractional laser(NAFL)in preventing postoperative pathological scar formation and intervention of inflammatory factors.Methods:93 patients with postoperative pathological scar formation who were admitted to our hospital from March 2022 to September 2024 were selected,they were divided into control group A(silicone gel treatment,n=31),control group B(NAFL on the basis of control group A,n=31)and study group(IPL on the basis of control group B,n=31)using the random number table method.The clinical efficacy,simple quality of life scale(SF-36),vancouver scar scale(VSS),inflammatory factors[interleukin-6(IL-6),tumor necrosis factor-α(TNF-α),C-reactive protein(CRP)],and adverse reactions among three groups were compared.Results:The clinical total effective rate in the study group were higher than those in the control group A and control group B(P<0.05).SF-36 increased sequentially and VSS decreased sequentially in control group A,control group B,and study group after treatment(P<0.05).CRP,IL-6,and TNF-α decreased sequentially in control group A,control group B,and study group after treatment(P<0.05).There was no significant difference in the incidence of adverse reactions among the three groups(P>0.05).Conclusion:IPL combined with NAFL in preventing postoperative pathological scar formation,can effectively reduce scar formation,reduce inflammatory factors levels,improve patients' quality of life,and be safe and reliable.
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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