1.SIRT5 Potentiates Hepatocarcinogenesis by Modulating Protein Acylation in Mice
Yu ZHANG ; Feng-Rui REN ; Jia-Yun LI ; Xiang-Yu CHEN ; Zi-Yi WANG ; Qi SUN ; Jun-Cheng ZHAO ; Ye ZHANG ; Zhen HUANG ; Hao HU ; Tao-Tao WEI ; Min XIAO
Progress in Biochemistry and Biophysics 2026;53(6):1712-1722
ObjectiveHepatocellular carcinoma (HCC) represents 90% of all primary liver cancers. The main risk factors associated with HCC include viral hepatitis (B and/or C), alcohol abuse, and metabolic dysfunction-associated steatotic liver disease (MASLD), which progressively advance to liver fibrosis, cirrhosis, and ultimately evolve into HCC. Surgical resection represents the most effective treatment for HCC, while recent advances in immunotherapy, including immune checkpoint inhibitors and adoptive cell therapies, have provided improved treatment prospects for patients with unresectable HCC. However, the complex metabolic heterogeneity of HCC limits the therapeutic efficacy. Metabolic intermediates acyl-CoA not only provide energy and substrates for numerous biochemical reactions but also serve as donors for protein lysine acylation, a major class of post-translational modification (PTM). Therefore, a deeper understanding of the molecular mechanisms underlying protein lysine acylation and hepatocarcinogenesis is urgently needed. MethodsThe levels of protein lysine acylation and silence information regulator 5 (SIRT5) expression levels in clinical HCC samples were analyzed by Western blot. Quantitative malonylome and succinylome of HCC samples were analyzed by antibody-based affinity enrichment coupled with tandem mass spectrometry. The proliferation of HCC cells was analyzed with Cell Counting Kit-8 (CCK-8) assays, the apoptosis was quantified by Annexin V-FITC/propidium iodide (PI) staining coupled with flow cytometry, and the ability of cells to migrate was assayed by Transwell assays. The enzymatic activity of glutathione S-transferase Mu 1 (GSTM1) was quantified. Transgenic mice with hepatic overexpression of SIRT5 were constructed using CRISPR-Cas9, and primary hepatocarcinogenesis was induced by administration of diethylnitrosamine. ResultsWestern blot analysis indicated that the expression level of SIRT5 was elevated in clinical samples from HCC patients, and the levels of lysine malonylation, glutarylation, and succinylation were significantly reduced in HCC tissues. Knockout of SIRT5 in MHCC-97H and MHCC-97L hepatoma cells suppressed cell proliferation, and increased the percentage of apoptotic cells significantly. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses of the differentially malonylome and succinylome of HCC samples revealed significant enrichment in two major classes of biological processes: core energy metabolism (e.g., glycolysis/gluconeogenesis, tricarboxylic acid metabolic process, fatty acid beta oxidation) and detoxification and oxidative stress response (e.g., response to toxic substance, chemical carcinogenesis, reactive oxygen species (ROS)). SIRT5 removes malonylation from lysine residues in GSTM1 and restores its detoxification activity, which is crucial for the survival of hepatocytes under stressed conditions. More importantly, in vivo experiment indicated that hepatic-specific overexpression of SIRT5 in mice accelerated diethylnitrosamine-induced liver fibrosis and hepatocarcinogenesis, indicating the critical role of SIRT5 in HCC progression. ConclusionThis study highlights the previously unrecognized SIRT5-GSTM1 axis as a key regulator in hepatocarcinogenesis, and suggests a potential target for the treatment of patients with HCC.
2.Clinical Efficacy of Modified Linggui Zhugan Tang in Patients with Obstructive Sleep Apnea-Hypopnea Syndrome of Spleen Deficiency and Dampness Obstruction with Blood Stasis Type and Its Effect on MIF, miR-223, and IL-18
Jun ZHANG ; Mengmei WEI ; Bo LI ; Yi YANG ; Changhui LINGHU ; Mingchang ZHANG ; Zhengxing GE
Chinese Journal of Experimental Traditional Medical Formulae 2026;32(9):171-179
ObjectiveTo investigate the intervention effects of modified Linggui Zhugan Tang (LGZGT) on patients with obstructive sleep apnea-hypopnea syndrome (OSAHS) of the spleen deficiency and dampness obstruction with blood stasis type, reveal its possible mechanisms, and provide a theoretical basis for the clinical treatment of OSAHS with traditional Chinese medicine (TCM). MethodsEighty OSAHS patients with spleen deficiency and dampness obstruction with blood stasis were randomly assigned to a control group and an observation group (1∶1) using a random number table, with 40 patients in each group. The control group received standard basic treatment combined with oral Doxofylline tablets, while the observation group received standard basic treatment combined with modified LGZGT. Serum levels of macrophage migration inhibitory factor (MIF), microRNA-223 (miR-223), and interleukin-18 (IL-18) were measured by enzyme-linked immunosorbent assay (ELISA), and the mRNA expression levels of MIF, miR-223, and IL-18 were measured by real-time quantitative polymerase chain reaction (Real-time PCR). After two months of treatment, the total clinical efficacy, apnea-hypopnea index (AHI), lowest nocturnal oxygen saturation (LSpO2), body mass index (BMI), TCM syndrome scores, and expression levels of MIF, miR-223, and IL-18 before and after treatment were compared between the two groups. Correlations between MIF, miR-223, IL-18 and AHI and LSpO2 were also analyzed. ResultsCompared with the control group, the observation group showed a significantly higher total clinical effective rate (P<0.01, Z=-3.49). Within the control group, no significant changes were observed in AHI, LSpO2, BMI, TCM syndrome scores, or MIF, miR-223, IL-18 levels and their mRNAs after treatment. In the observation group, AHI, BMI, TCM syndrome scores, and MIF and IL-18 levels and their mRNAs decreased significantly, while LSpO2 increased significantly (P<0.01). After treatment, compared with the control group, the observation group exhibited significantly lower AHI, BMI, TCM syndrome scores, and MIF and IL-18 levels and their mRNAs, and significantly higher LSpO2 (P<0.01). Correlation analysis showed that MIF and IL-18 were positively correlated with AHI (P<0.01) and negatively correlated with LSpO2 (P<0.01), whereas miR-223 was negatively correlated with AHI (P<0.01) and positively correlated with LSpO2 (P<0.01). ConclusionModified LGZGT may improve OSAHS of the spleen deficiency and dampness obstruction with blood stasis type by reducing airway inflammatory factors, alleviating airway inflammation, relieving airway edema and stenosis, and improving airway obstruction.
3.Expert consensus on neoadjuvant PD-1 inhibitors for locally advanced oral squamous cell carcinoma (2026)
LI Jinsong ; LIAO Guiqing ; LI Longjiang ; ZHANG Chenping ; SHANG Chenping ; ZHANG Jie ; ZHONG Laiping ; LIU Bing ; CHEN Gang ; WEI Jianhua ; JI Tong ; LI Chunjie ; LIN Lisong ; REN Guoxin ; LI Yi ; SHANG Wei ; HAN Bing ; JIANG Canhua ; ZHANG Sheng ; SONG Ming ; LIU Xuekui ; WANG Anxun ; LIU Shuguang ; CHEN Zhanhong ; WANG Youyuan ; LIN Zhaoyu ; LI Haigang ; DUAN Xiaohui ; YE Ling ; ZHENG Jun ; WANG Jun ; LV Xiaozhi ; ZHU Lijun ; CAO Haotian
Journal of Prevention and Treatment for Stomatological Diseases 2026;34(2):105-118
Oral squamous cell carcinoma (OSCC) is a common head and neck malignancy. Approximately 50% to 60% of patients with OSCC are diagnosed at a locally advanced stage (clinical staging III-IVa). Even with comprehensive and sequential treatment primarily based on surgery, the 5-year overall survival rate remains below 50%, and patients often suffer from postoperative functional impairments such as difficulties with speaking and swallowing. Programmed death receptor-1 (PD-1) inhibitors are increasingly used in the neoadjuvant treatment of locally advanced OSCC and have shown encouraging efficacy. However, clinical practice still faces key challenges, including the definition of indications, optimization of combination regimens, and standards for efficacy evaluation. Based on the latest research advances worldwide and the clinical experience of the expert group, this expert consensus systematically evaluates the application of PD-1 inhibitors in the neoadjuvant treatment of locally advanced OSCC, covering combination strategies, treatment cycles and surgical timing, efficacy assessment, use of biomarkers, management of special populations and immune related adverse events, principles for immunotherapy rechallenge, and function preservation strategies. After multiple rounds of panel discussion and through anonymous voting using the Delphi method, the following consensus statements have been formulated: 1) Neoadjuvant therapy with PD-1 inhibitors can be used preoperatively in patients with locally advanced OSCC. The preferred regimen is a PD-1 inhibitor combined with platinum based chemotherapy, administered for 2-3 cycles. 2) During the efficacy evaluation of neoadjuvant therapy, radiographic assessment should follow the dual criteria of Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 and immune RECIST (iRECIST). After surgery, systematic pathological evaluation of both the primary lesion and regional lymph nodes is required. For combination chemotherapy regimens, PD-L1 expression and combined positive score need not be used as mandatory inclusion or exclusion criteria. 3) For special populations such as the elderly (≥ 70 years), individuals with stable HIV viral load, and carriers of chronic HBV/HCV, PD-1 inhibitors may be used cautiously under the guidance of a multidisciplinary team (MDT), with close monitoring for adverse events. 4) For patients with a poor response to neoadjuvant therapy, continuation of the original treatment regimen is not recommended; the subsequent treatment plan should be adjusted promptly after MDT assessment. Organ transplant recipients and patients with active autoimmune diseases are not recommended to receive neoadjuvant PD-1 inhibitor therapy due to the high risk of immune related activation. Rechallenge is generally not advised for patients who have experienced high risk immune related adverse events such as immune mediated myocarditis, neurotoxicity, or pneumonitis. 5) For patients with a good pathological response, individualized de escalation surgery and function preservation strategies can be explored. This consensus aims to promote the standardized, safe, and precise application of neoadjuvant PD-1 inhibitor strategies in the management of locally advanced OSCC patients.
4.Analysis of completion rate of tumor evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer : a national multicenter real-world study
Kexuan LI ; Tixian XIAO ; Xiaodong WANG ; Bin WU ; Guole LIN ; Yuchen GUO ; Ming QU ; Si WU ; Xiaodong YANG ; Yinshengbo′er BAO ; Baohua WANG ; Fan ZHANG ; Xiangwang YU ; Beizhan NIU ; Junyang LU ; Lai XU ; Guannan ZHANG ; Zhen SUN ; Guoyou ZHANG ; Yan SHI ; Hong JIANG ; Yongjing TIAN ; Yongxiang LI ; Hongwei YAO ; Jun XUE ; Quan WANG ; Lie YANG ; Qian LIU ; Yi XIAO
Chinese Journal of Digestive Surgery 2025;24(1):113-119
Objective:To investigate the completion rate of tumor evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients in the national multicenter real-world database.Methods:The prospective real-world study was conducted. The clinicopathological data of 1 074 patients who underwent surgical treatment for mid and low rectal cancer in 47 national medical institutions, including Peking Union Medical College Hospital et al, from May 12,2023 to May 11,2024 were collected. Observation indicators: (1) clinical characteristics of patients with mid and low rectal cancer; (2) initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer; (3) initial imaging evaluation of patients with mid and low rectal cancer; (4) imaging evaluation after neoadjuvant therapy for patients with mid and low rectal cancer. Measurement data with normal distribution were represented as Mean± SD, and measurement data with skewed distribution were represented as M( Q1, Q3). Count data were described as absoluter numbers and/or percentages. Results:(1) Clinical characteristics of patients with mid and low rectal cancer. Of the 1 074 patients, there were 713 males and 361 females, aged 63(56,70)years. The body mass index of 1 074 patients was 24(21,26)kg/m 2.For American Society of Anesthesiologists classification, there were 147 cases of stage Ⅰ, 641 cases of stage Ⅱ, 157 cases of stage Ⅲ, 2 cases of stage Ⅳ, and there were 127 cases missing data. (2) Initial colonoscopy and pathologic evaluation of tumors in patients with mid and low rectal cancer. Of the 1 074 patients, there were 787 cases (73.28%) undergoing complete colonoscopy, and there were only 197 cases (18.34%) undergoing immunohistochemical evaluation of all four mismatch repair proteins. (3) Initial imaging evaluation of patients with mid and low rectal cancer. Of the 1 074 patients, there were 842(78.40%) patients completing magnetic resonance imaging (MRI) or ultrasound evaluation, and there were 914(85.10%) patients completing chest, abdomen, and pelvis enhanced computed tomography (CT) evaluation. In the 149 patients completing rectal ultrasound evaluation, there were 122 cases (81.88%) comple-ting T staging evaluation, and there were 81 cases (54.36%) completing N staging evaluation. In the 808 patients completing rectal MRI evaluation, there were 708 cases (87.62%) completing T staging evaluation, and there were 590 cases (73.02%) completing N staging evaluation. (4) Imaging evalua-tion after neoadjuvant therapy for patients with mid and low rectal cancer. Of the 388 patients with neoadjuvant therapy, there were 332 patients (85.57%) completing MRI or ultrasound evaluation, and there were 327 patients (84.28%) completing chest, abdomen, and pelvis enhanced CT evalua-tion. In the 70 patients completing rectal ultrasound evaluation, there were 65 cases (92.86%) com-pleting T staging evaluation, and there were 49 cases (70.00%) completing N staging evaluation. In the 327 patients completing rectal MRI evaluation, there were 246 cases (75.23%) completing T staging, and there were 228 cases (69.72%) completing N staging evaluation. Conclusion:The com-pletion rate of tumor imaging evaluation at initial assessment and after neoadjuvant therapy for mid and low rectal cancer patients on a national scale is relatively good.
5.Frontalis sling surgery using polypropylene non-absorbable sutures: a novel approach for the treatment of senile ptosis
Yi YANG ; Xueyong MENG ; Jun ZHANG ; Jinlong HUANG
Chinese Journal of Plastic Surgery 2025;41(1):8-14
Objective:To investigate the effect of a new method of utilizing frontalis sling with polypropylene non-absorbable sutures for the treatment of senile ptosis.Methods:A retrospective analysis was conducted on the clinical data of senile patients with blepharoptosis who were treated with frontalis sling surgery with polypropylene non-absorbable sutures at the Department of Plastic Surgery, Affiliated Hospital of Nanjing University of Chinese Medicine between January 2022 and December 2023. The palpebral fissure height and margin reflex distance (MRD1) of the upper eyelid margin were measured and recorded before and after the operation, and the operation time and postoperative detumescence time were recorded. Postoperative complications and recurrence of ptosis were followed up. Patients’ satisfaction with the postoperative effect was investigated and divided into three levels: very satisfied, satisfied, and dissatisfied. Normal distribution measurement data were expressed as Mean±SD; counting data were expressed as frequency.Results:A total of 8 patients were enrolled, including 3 males and 5 females, with an age of (68.8±6.1) years. Six patients underwent bilateral ptosis correction surgery, and two underwent unilateral ptosis correction surgery. The ptosis was graded as follows: 1 case was mild, 2 cases were moderate, and 5 cases were severe. There were 2 cases of aponeurotic ptosis, 3 cases of congenital ptosis and 3 cases of traumatic ptosis (1 of which was prosthetic eye). The operative time of 8 patients (14 eyes) with unilateral ptosis was (43.9±4.9) min. The swelling resolved in (9.4±1.7) days. One patient still had symptoms of lagophthalmos and corneal irritation 7 days after the operation. The symptoms gradually relieved after wearing corneal protective goggles and applying eye ointment. The postoperative follow-up lasted from 2 to 15 months (mean 6.3 months). Palpebral cleft height [(9.8±0.6) mm vs. (3.3±1.2) mm] and MRD1[(4.1±0.5) mm vs. (-1.1±0.8) mm] in 8 patients (14 eyes) after surgery were significantly higher than those before the operation( P<0.01). There was no recurrence of ptosis after the operation. There were 2 cases of upper eyelid hysteresis, of which 1 case was mild upper eyelid hysteresis, and the other case had relatively obvious upper eyelid hysteresis on prosthetic side. Satisfaction survey showed that 7 patients were very satisfied with the result of the operation, and 1 patient was satisfied. Conclusion:Frontal muscle suspension with polypropylene non-absorbable suture is a feasible method for the treatment of ptosis in elderly patients with simple operation, little tissue damage, positive effect, rapid postoperative recovery and acceptable complications.
6.Clinical efficacy of three surgical approaches for repairing adult giant atrial septal defects
Chunzhu XUE ; Yang HE ; Banghui LAI ; Jun CHEN ; Yi ZHANG ; Shungang LI ; Xianzhi WANG ; Cunfu MU
Chongqing Medicine 2025;54(9):2142-2146
Objective To compare the clinical efficacies among three surgical approaches of small inci-sion in the lower segment of the sternum,small incision in the right axilla and thoracoscopic 3 incisions for re-pairing adult giant atrial septal defects(ASD).Methods The medical records of 112 patients with giant ASD undergoing surgical repair in this hospital from January 2018 to January 2024 were retrospectively analyzed.According to the different surgical approaches,the patients were divided into the group A(n=35,small inci-sion in the lower part of the sternum),group B(n=37,small incision in the right axilla)and group C(n=40,thoracoscopic 3 incisions).The general data,operation time,cardiopulmonary bypass time,blood transfusion volume,incision length,postoperative VAS score,postoperative mechanical ventilation time,ICU stay time,postoperative hospitalization duration,hospitalization cost and postoperative complications occurrence rates were compared among the various groups.Results There were no statistically significant differences in the operation time,cardiopulmonary bypass time,blood transfusion volume,postoperative mechanical ventilation time,ICU stay time and postoperative hospitalization duration among 3 groups(P>0.05).The hospitalization cost in the group C was higher than that in the groups A and group B,the postoperative VAS score in the group B was higher than that in the group A and C,the incision size in the group C was shorter than that in the group A and group B,and the differences were statistically significant(P<0.05).All patients were suc-cessfully repaired.The incidence rate of postoperative pulmonary infection in the group A and group C was lower than that in the group B,and the difference was statistically significant(P<0.05).Conclusion All three surgical approaches could safely and effectively repair adult giant ASD.Different surgical approaches should be selected based on the specific conditions of the patients.
7.Studies on the Design and Activity of Anticancer Peptides Based on the Weak Acidic Microenvironment of Tumors
Yue-Qi NIE ; Miao JIANG ; Hui-Yan WU ; Chang-Hao DING ; Wei REN ; Jun-Yi CHANG ; Ke CHEN ; Shao-Long DU ; Peng ZHANG ; Zhong-Hua LIU
Chinese Journal of Biochemistry and Molecular Biology 2025;41(10):1380-1391
Lung cancer poses a serious threat to global public health security.Chemotherapy,as the main strategy for cancer treatment,faces challenges such as high toxicity and drug resistance.Anticancer peptides have the potential of being developed into new anticancer drugs due to their advantages of broad-spectrum anticancer activity,rapid action,and difficulty in generating drug resistance,but they also face shortcomings such as weak activity and strong toxic side effects.The weakly acidic microenvironment of tumors(pH 6.5-6.8)provides a good idea for the design of anticancer peptides of high-efficiency and low-toxicity.Previously,we designed the acid-sensitive antibacterial peptide pHly-1 using the wolf spider(Lycosa singoriensis)toxin Lycosin-Ⅰ as a template.In this study,we found that pHly-1 also had acid-sensitive anticancer activity.Further alanine scanning analysis of pHly-1 was carried out,and we ob-tained a mutant pHTP-2 with better acid sensitivity,whose IC50(half maximal inhibitory concentration)against A549 cells was 15.68 μmol/L at pH 6.6 and was greater than 100 μmol/L at pH 7.4.At pH 6.6,pHTP-2 could act on various lung cancer cell lines and induce the death of A549 cells by rapid ly-sis;at pH 7.4,500 μmol/L pHTP-2 had weak toxicity to red blood cells(the hemolysis rate was ap-proximately 38%)and primary myocardial cells(the inhibition rate was 49.7%,with P<0.05).Analy-sis of its charge,particle size,morphology,and secondary structure showed that at pH 6.6,the histidine in the sequence of pHTP-2 was protonated,increasing the positive charge(P<0.01),decreasing the hy-drated particle size(P<0.05)and forming an α-helical structure to induce membrane lysis of A549 cells.At pH 7.4,it was deprotonated,the positive charge decreases,a β-sheet structure was formed and self-aggregation occurred,limiting its effect on the A549 cell membrane and showing weak activity.In summary,pHTP-2 could respond to the weakly acidic microenvironment of tumors to exert selective cyto-toxic activity,effectively overcoming the shortcomings of anticancer peptides such as low efficiency and high toxicity.Our findings suggest that it is a high-quality lead molecule for anticancer drugs.
8.Prevalence and influencing factors of chronic somatic comorbidities in patients with schizophrenia in Shanghai communities
Wei-bo ZHANG ; Jiang-nan LI ; Yan-li LIU ; Yi-zhou JIANG ; Yi ZHU ; Na WANG ; Jun CAI
Fudan University Journal of Medical Sciences 2025;52(4):484-491,499
Objective To investigate the prevalence of chronic somatic comorbidities in schizophrenic patients in Shanghai communities,and to explore the factors influencing comorbidities.Methods Based on Shanghai community-based severe mental disorders cohort,5 422 patients with schizophrenia(SCZ)were included in the study.12 common chronic somatic diseases,defined by patients'self-report,were selected to analyze the prevalence of comorbidity,and Logistic regression model was used to analyze the factors influencing the number of somatic comorbidities.Results The total prevalence of somatic comorbidity was 37.0%in 5 422 patients with SCZ,with the highest prevalence of hypertension(22.6%)and diabetes mellitus(13.1%)among 12 somatic diseases selected.Older age was the main factor associated with chronic somatic comorbidities in community schizophrenic patients.The risk of 1-2 comorbidities in patients aged≥60 years was 3.34(95%CI:2.74-4.07)times higher than those aged<45 years,while the risk of≥3 comorbidities was 3.27(95%CI:2.11-5.09)times higher,correspondingly.Female gender,marriage,smoking,and longer duration of illness were also risk factors for comorbidity.Women after menopause had higher risk of comorbidity than perimenopausal women.Conclusion Cardiovascular and metabolic diseases were common somatic comorbidities among schizophrenic patients in Shanghai communities.Older age,female gender,marriage,smoking,and longer duration of illness were risk factors for increasing number of comorbidities.
9.RICH1 regulates myocardial fibrosis through TGF-β/SMAD signaling pathway
Lu-xuan WAN ; Ying-qing HU ; Yuan-yuan LIU ; Yong-song TANG ; Jun-yi HUANG ; Zi-xuan ZHANG ; Xiao-xiao MAO ; Xin-wen NIE ; Zhan-hong REN
Chinese Pharmacological Bulletin 2025;41(11):2089-2096
Aim To reveal the mechanism of CIP4 homologs protein 1(RICH1)are involved in the regu-lation of myocardial fibrosis.Methods Mouse cardiac fibroblasts(MCFs)cells were treated with transforming growth factor-β(TGF-β1)to induce the formation of a myocardial fibrosis cell model;the level of the target protein was detected by Western blotting;and the RICH1 gene was detected by transfection of the cells with plasmid.The RICH1 gene was overexpressed(RICH 1 OE)using plasmid transfection;the RICH1 gene was silenced using siRNA fragment(siRICH1);and the expression levels of myocardial fibrosis marker genes,such as Col1 a1,Col3 a1,and Acta2,were de-tected using RT-qPCR.Results RICH1 was signifi-cantly down-regulated in TGF-β1-treated MCFs;the expression levels of myocardial fibrosis marker genes,such as Col1 a1,Col3a1,and Acta2,were down-regu-lated in the RICH1 OE+TGF-β1 group;and in the siRICH1+TGF-β1 group,myocardial fibrosis marker genes,such as Col1 a1,Col3a1 and Acta2 were up-regulated at the expression level;phosphorylated SMAD2(p-SMAD2)and phosphorylated SMAD3(p-SMAD3)levels were down-regulated in the siRICH1 OE+TGF-β1 group.p-SMAD2 and P-SMAD3 levels were upregulated in the siRICH1+TGF-β1 group.Conclusion RICH1 inhibits TGF-β1-induced myo-cardial fibrosis;RICH1 inhibits TGF-β1-induced myo-cardial fibrosis by negatively regulating the SMAD2/3 signaling pathway.
10.Experimental and Computational Investigation of pH-Dependent Urease Conformational Dynamics and Its Impact on MICP Efficiency
Qiu-Cai ZHANG ; Yi-Fei ZHENG ; Mei-Zhong HUANG ; Xiu-Kang SHEN ; Ling-Ling WU ; Zhi-Jun ZHANG
Chinese Journal of Biochemistry and Molecular Biology 2025;41(6):879-894
The engineering application of microbially induced carbonate precipitation(MICP)is limited by pH-dependent conformational dynamics of urease.Focusing on the α-subunit urease from Sporosarcina pasteurii,this study integrated conductivity experiments and constant-pH molecular dynamics simulations to analyze active site conformational dynamics and catalytic function across pH 3-11.Results showed that under neutral conditions(pH 7-8),key histidine residues(HIS139/HIS249)exhibited minimal dis-placement(<0.5 ?),the longest hydrogen bond lifetime(>8 ps),highest conformational stability(root mean square deviation,RMSD:0.15-0.18 nm),and optimal catalytic activity(conductivity change rate:0.03 mS/cm·min-1,CaCO3 precipitation:3.84 g).Extreme pH(pH 3/11)induced structural collapse(displacement up to 1.8 ?)and complete activity loss.Simulations revealed that neutral pH sta-bilizes a protonation-dependent cooperative allosteric network by maintaining active site cavity volume(~120 ?3)and moderate conformational coherence(correlation coefficient~0.8).This work deciphers the molecular mechanism of pH-regulated urease dynamics through protonation states,providing theoreti-cal support for MICP applications in acidic mine tailing remediation and alkaline soil stabilization.


Result Analysis
Print
Save
E-mail