1.Mass Spectrometry-based Antibody Sequencing Technologies
Sheng-Mei LIU ; Peng XUE ; Xiao-Jian WANG
Progress in Biochemistry and Biophysics 2026;53(4):840-854
Antibodies play a critical role in adaptive immune responses and serve as key components in disease diagnosis and treatment. These molecules exhibit dynamic post-translational modifications (PTMs), such as glycosylation and phosphorylation, which regulate their effector functions. To date, nearly all of our knowledge about antibody repertoires has come from B cell receptor (BCR) sequencing (BCR-seq), which facilitates the profiling of clonal composition and the tracing of maturation trajectories within B-cell repertoires. However, circulating antibodies found in bodily fluids—such as serum, saliva, milk, mucosal secretions, and cerebrospinal fluid—exhibit diversities and specificities beyond what BCR-seq alone can predict. Therefore, identifying and quantifying antibody clonotypes at the protein level could enhance diagnosis, prognosis, and treatment strategies in personalized medicine. The critical gap between genotype and phenotype necessitates complementary methodologies that enable the direct characterization of antibody proteins in their native functional states. Mass spectrometry (MS)-based antibody repertoire sequencing (Ab-seq) is currently the only feasible approach for this task and primarily includes database-dependent methods—such as bottom-up, middle-down, and top-down approaches—as well as database-independent de novo sequencing technology. These strategies enable multi-level, high-precision characterization ranging from peptides and domains to intact antibody molecules. Unlike the shotgun strategy commonly used in routine proteomics, obtaining full sequences of all antibodies presents unique challenges. It requires specialized methodological adaptations to address issues related to dynamic range, sequence variation, and sample complexity. This review introduces the technical principles, methodological workflows, and recent applications of various mass spectrometry-based antibody repertoire sequencing (Ab-seq) strategies, with a focus on approaches designed to improve sequence coverage and identification accuracy. These include multi-enzyme digestion, hybrid fragmentation methods, and artificial intelligence-assisted de novo sequencing. By systematically comparing database-dependent techniques—such as bottom-up, middle-down, and top-down approaches—with database-independent de novo sequencing, this review outlines their respective advantages and limitations in terms of sample throughput, sequence coverage, post-translational modification characterization, and data analysis complexity. In addition, this review discusses emerging technological trends, including the integration of ion mobility separation, native mass spectrometry, and artificial intelligence-driven data interpretation, which are expected to enhance the depth and accuracy of antibody characterization. Although current methods continue to face challenges related to sample complexity, dynamic range, and unambiguous sequence variant assignment, we emphasize the importance of integrating BCR-seq and Ab-seq data to construct gene-protein association maps. These maps help validate sequence accuracy and facilitate epitope discovery. This dual-platform strategy helps bridge the gap between genotype and phenotype, thereby enhancing both the resolution and scope of antibody repertoire studies. Such an integrative approach also offers a valuable tool for therapeutic antibody development, structure-function analysis, and precise evaluation of vaccine efficacy.
2.β-glucan attenuates intestinal ischemia-reperfusion injury in mice by promoting glucagon-like peptide-1 secretion
Wei WANG ; Ben HAN ; Lihua SUN ; Huichao XIE ; Xiong ZENG ; Weidong XIAO ; Jian WANG
Journal of Army Medical University 2025;47(2):112-121
Objective To investigate the protective effect of β-glucan(BG)against intestinal ischemia reperfusion(II/R)injury by regulating the secretion of glucagon-like peptide-1(GLP-1).Methods Male C57BL/6 mice(6~8 weeks old)were subjected,and finally,the experiments had sham group,II/R group,II/R+BG group(0.1 mg/mL BG in drinking water for 2 weeks before modeling),II/R+liraglutide(LLT,GLP-1 analogue)group(0.2 μg/g LLT injected every 12 hours for 3 consecutive days before modeling),and II/R+BG+Ex9-39(GLP-1 R antagonist)group(intraperitoneal injection of 2 μg/g Ex9-39 1 h before modeling).After modeling,HE staining was used to observe intestinal morphological changes,and RT-qPCR and Western blotting were employed to evaluate the molecules(Occludin,ZO-1 and Claudin-1)related to intestinal barrier damage.The effect of 0.1 mg/mL BG treatment on the GLP-1 level in the serum and intestinal tissues of normal mice was determined with ELISA and immunofluorescence assay,respectively,and RT-PCR for the molecules related to GLP-1 expression(Gcg,Pcsk1/2,GIP and Foxa2).The effects of LLT and Ex9-39 pretreatment on intestinal morphology and intestinal barrier damage were also determined by morphological observation and expression levels of related molecules.Results II/R induced significant decreases in the mRNA levels of Occludin,ZO-1 and Claudin-1 and increase in Chiu's score when compared with sham control mice(P<0.05).While,the mRNA levels of the 3 molecules were obviously higher and the Chiu's score was lower in the II/R+BG group than the II/R group(P<0.05).BG pretreatment induced notably enhanced secretion of GLP-1 in the serum and intestinal tract of normal mice,and improved the mRNA expression of GLP-1-related molecules(P<0.05).The intervention of GLP-1 analogue LLT could attenuate the II/R damage and decreased Chiu's score,with statistical difference in comparison with the II/R group(P<0.05).GLP-1 receptor antagonist Ex9-39 reversed the protective effects of BG pretreatment against II/R damage,with notably differences in the expression of Occludin,ZO-1 and Claudin-1 and Chiu's score(P<0.05).Conclusion BG can attenuate intestinal mucosal and functional injury after II/R by promoting intestinal GLP-1 secretion.
3.Research Advances of Deep Learning-based Raman Spectroscopy and Their Application in Detection of Microplastics
Yong-Hui HAN ; Chun-Bo SHI ; Wang LIANG ; Xiao-Yue ZHANG ; Jian-Sheng CUI ; Bo YAO
Chinese Journal of Analytical Chemistry 2025;53(2):153-163
Microplastics are widely present in various environments such as water bodies,land,and atmosphere,which pose threats to the ecological environment and human health through transmission and accumulation in the food chain.The existing detection techniques for microplastics face challenges such as complex preparation procedure of samples,low efficiency in processing large batches of samples,and difficulties in handling complex samples.Therefore,there is an urgent need for rapid and efficient detection techniques suitable for complex microplastics samples in the field of environmental monitoring.Raman spectroscopy,known for its advantages such as rapidity,accuracy,high sensitivity,non-destructiveness,and non-contact,demonstrates great application potential in detection of microplastics.Deep learning,an artificial intelligence method known for its large-scale data processing,nonlinear modeling and automatic feature extraction capabilities,is receiving increasing attention in the analysis of Raman spectroscopy signals.The application of deep learning-based Raman spectroscopy has significantly improved performance indicators such as detection efficiency and accuracy.This article introduced the existing Raman enhancement techniques,summarized the deep learning methods applied in Raman spectroscopy signal analysis,reviewed the recent research and application progress of deep learning-based Raman spectroscopy in detection of microplastics,and finally discussed the challenges and future prospects of deep learning-based Raman spectroscopy in detection of microplastics.
4.Synthesis and Identification of Saturated Arsenic-containing Hydrocarbons
Jia-Jia CHEN ; Ying-Xiong ZHONG ; Xin-Huang KANG ; Chun-Mei DENG ; Bing-Bing SONG ; Xiao-Fei LIU ; Zhuo WANG ; Rui LI ; Jian-Ping CHEN ; Xue-Jing JIA ; Sai-Yi ZHONG
Chinese Journal of Analytical Chemistry 2025;53(3):472-480
Arsenic is a semi-metal,and lipid-soluble arsenic compounds are one of the widespread forms in the environment and food chain,but there is a lack of standards for lipid-soluble arsenic compounds,which is one of the bottlenecks in the current analytical detection and toxicological studies of organic arsenic.In this study,four saturated arsenic-containing hydrocarbons,AsHC 318,AsHC 332,AsHC 346,and AsHC 374(The number is relative molecular mass),were successfully synthesized in three steps by using dimethylarsinic acid,potassium iodide,sodium hydroxide,and four brominated alkanes(1-Bromotetradecane,1-bromopentadecane,1-bromohexadecane,and 1-bromooctadecane)as raw materials.The structures of these four saturated arsenic-containing hydrocarbons were characterized by proton nuclear magnetic resonance(1H NMR)spectroscopy,13C nuclear magnetic resonance(13C NMR)spectroscopy,and high-resolution mass spectrometry(HR-MS).The yields of the method were 8%-10%,and the synthesized compounds could be used in subsequent toxicity evaluation experiments to assess the toxic effects and mechanisms of action of arsenic-containing hydrocarbons.This study provided an effective method for synthesis of arsenic-containing hydrocarbons,enriching the synthesis methods of arsenic-containing hydrocarbons,and provided raw materials for the subsequent toxicological studies of arsenic-containing hydrocarbons.
5.Dual-modal Magnetic Resonance Imaging Contrast Agents Based on Polymetallic Nanoclusters for Targeted Diagnosis of Prostate Cancer
Qing-Dong LI ; Peng WANG ; Jian-Min XIAO ; Wen-Juan GAO ; Zhen-Hong XIA ; Gui-Long ZHANG ; Zheng-Yan WU
Chinese Journal of Analytical Chemistry 2025;53(4):602-611
Fe/Mn/Gd polymetallic nanooxide(FMGN)were prepared by one-step solvent thermal reaction by using Fe(acac)3,Mn(acac)2 and Gd(acac)3 as reaction precursors.Next,hyaluronic acid(HA)was used to modify FMGN to fabricate tumor-targeting T 1-T 2 dual-mode magnetic resonance imaging(MRI)contrast agent(HA-FMGN)for accurate diagnosis of prostate cancer.The structure and morphology of FMGN were observed by transmission electron microscope(TEM).It was found that FMGN exhibited a uniform nanocluster spherical structure when the feeding ratio of iron acetylacetonate,manganese acetylacetonate,and gadolinium acetylacetonate was 3:2:1.X-ray diffraction(XRD)analysis showed that FMGN had a typical inverse spinel structure of Mn doped Fe 3O 4,with Gd existing in the form of amorphous gadolinium oxide.The longitudinal relaxivity(r 1)and transverse relaxivity(r 2)of FMGN were 13.395 and 428.535 L/(mmol·s),respectively,measured by 0.5 T MRI analyzer,which proved that FMGN had excellent T 1-T 2 dual-mode MRI contrast capability.The cytotoxicity and hemolysis test found that HA-FMGN didn't damage red cells and induce toxicity for normal cells,indicating that HA-FMGN had excellent cell biocompatibility.The internalization efficacy of HA-FMGN was observed by CLSM,and the results showed that HA-FMGN possessed excellent prostate tumor-targeting ability.In vivo MRI experiment showed that HA-FMGN significantly enhanced T 1 and T 2 weighted MRI signal to noise ratio(SNR)of prostate tumor,which promoted the accurate diagnosis of orthotopic prostate cancer.
6.Preparation and In Vitro Degradation Characteristics Analysis of Poly(lactic-co-glycolide)Microspheres Based on Microfluidic Process
Bao-Cheng WANG ; Cong-Yu MA ; Ke WANG ; Si-Tong ZHENG ; Xiao-Yan ZHANG ; Yue-Mei ZHAO ; Xun ZHAO ; Jian-Bin PAN ; Zheng-Song GAO ; Hai-Wei SHI ; Yao-Zuo YUAN ; Hong-Yuan CHEN
Chinese Journal of Analytical Chemistry 2025;53(4):621-630
Poly(lactic-co-glycolide)(PLGA)is a key excipient in long-acting sustained-release preparations,and its degradation properties directly affect the drug release behavior.In this study,PLGA microspheres were prepared by microfluidic techniques,and the morphology changes of the microspheres were observed by scanning electron microscopy(SEM).In alkaline environment,due to the accelerated hydrolysis of ester bonds,the surface of the microspheres was rapidly dissolved and eroded,and the degradation rate was significantly higher than that in acidic environment.High temperature accelerated the degradation of PLGA microspheres.Under neutral and alkaline conditions,the microspheres showed aggregation and adhesion.Under acidic conditions,the microspheres gradually decomposed into irregular fragments.The high ionic strength further promoted the surface corrosion of the microspheres,especially under extreme pH conditions.Simultaneously,PLGA microspheres encapsulating coumarin were prepared to simulate the microsphere formulation.The release rate of coumarin after degradation of the microspheres under different conditions was observed by measuring the absorbance with ultraviolet-visible spectrophotometry.The results were consistent with those of the blank microspheres.This study revealed that the degradation of PLGA microspheres was significantly pH-dependent,temperature sensitive and ion strength responsive.These findings not only helped to understand and optimize the long-term stability and controlled release performance of drug-carrying microspheres,but also provided a theoretical basis for further improvement of PLGA-based drug carrier design.
7.Synthesis and Applications of Indole-3-formylhydrazine Modified Pyrene Schiff Base Compound as Copper Ion Fluorescence Probe
Mu-Xi WANG ; Zhen-Yu HUANG ; Xiao-Feng LIN ; Xiao-Lan LEI ; Jian SUN ; Li-Jun MA
Chinese Journal of Analytical Chemistry 2025;53(7):1108-1117
In this work,a fluorescent probe PIN was synthesized using indole-3-carbohydrazide and pyrenecarboxaldehyde as raw materials.PIN showed weak fluorescence emission in aqueous solution with acetonitrile volume fraction of 70%.However,when Cu2+was added to this aqueous solution of PIN,a new fluorescence emission peak appeared at 495 nm,and the intensity of this peak gradually increased with the increase of concentration of Cu2+,and also caused a significant change in the fluorescence color of the solution.In contrast,the addition of 15 kinds of other common metal ions did not cause such change.The detection limit of PIN for Cu2+was 78.7 nmol/L,which was much lower than the maximum permitting level of Cu2+in drinking water in hygienic standard for drinking water in China.Therefore,PIN was a highly selective and sensitive fluorescence-enhanced probe for Cu2+.Meanwhile,the addition of Cu2+could also cause a new absorption peak at 440 nm in the ultraviolet-visible absorption spectrum of the aqueous solution of PIN,and meanwhile the colorless PIN solution changed into yellow,exhibiting the performance of PIN as a colorimetric probe for Cu2+.By fitting with the Levenberg-Marquardt algorithm equation,the binding ratio of PIN to Cu2+was 2:1,and the binding constant was 3.42×1012 L2/mol2.In addition,the binding mode of PIN with Cu2+was explored by using proton nuclear magnetic resonance(1H NMR)titration experiments and density functional theory simulations.The results showed that the addition of Cu2+could cause the aggregation of PIN molecules to form excimers,thus showing highly selective recognition.Finally,PIN was made into a simple test strip,which could achieve rapid and convenient fluorescence detection of Cu2+in actual water samples.
8.Validation and Forensic Application of a Domestic Human DNA Quantitative De-tection Kit
Jing CHEN ; Ya-Ping WANG ; Yun-Peng FENG ; Xiao-Xin HU ; Zhen-Jun JIA ; Hong-Di LIU ; An-Xin YAN ; Yong-Jiu LI ; Zhu PENG ; Zhi-Fang LIU ; Jian-Gang CHEN
Journal of Forensic Medicine 2025;41(3):252-259
Objective To verify the efficacy of a domestic human DNA quantification kit based on real-time fluorescence quantitative PCR in detecting the total human DNA concentration,male DNA concen-tration in mixed male/female DNA samples,the degree of DNA degradation and inhibitor tolerance.Methods Samples with different concentrations,different male/female ratios,different concentrations of inhibitors,and different degradation degrees were tested using the domestic human DNA quantification kit based on real-time fluorescence quantitative PCR.This kit was compared with a similar product on the market and was applied to the detection of DNA from real cases.Results This human DNA quan-tification kit can effectively detect human DNA as low as 0.001 65 ng/μL,and 6.25 pg/μL of male DNA in mixed samples with a male-to-female ratio of 1∶15 000.Even when the sample contains as high as 400 ng/μL of humic acid or 1 000 μmol/L of hemin alone,the DNA concentration can still be accurately detected.The degradation index can effectively characterize the degradation degree of the sample.This kit has been successfully applied in forensic practice.Conclusion This human DNA quan-tification kit is accurate and reliable in detection.It can accurately reflect the degradation of DNA and inhibitor tolerance.It has good performance in quantitative accuracy,determination of the male/female ratio in mixed samples,and inhibitor tolerance.It has application potential in forensic case examination.
9.Criteria and prognostic models for patients with hepatocellular carcinoma undergoing liver transplantation
Meng SHA ; Jun WANG ; Jie CAO ; Zhi-Hui ZOU ; Xiao-ye QU ; Zhi-feng XI ; Chuan SHEN ; Ying TONG ; Jian-jun ZHANG ; Seogsong JEONG ; Qiang XIA
Clinical and Molecular Hepatology 2025;31(Suppl):S285-S300
Hepatocellular carcinoma (HCC) is a leading cause of cancer-associated death globally. Liver transplantation (LT) has emerged as a key treatment for patients with HCC, and the Milan criteria have been adopted as the cornerstone of the selection policy. To allow more patients to benefit from LT, a number of expanded criteria have been proposed, many of which use radiologic morphological characteristics with larger and more tumors as surrogates to predict outcomes. Other groups developed indices incorporating biological variables and dynamic markers of response to locoregional treatment. These expanded selection criteria achieved satisfactory results with limited liver supplies. In addition, a number of prognostic models have been developed using clinicopathological characteristics, imaging radiomics features, genetic data, and advanced techniques such as artificial intelligence. These models could improve prognostic estimation, establish surveillance strategies, and bolster long-term outcomes in patients with HCC. In this study, we reviewed the latest findings and achievements regarding the selection criteria and post-transplant prognostic models for LT in patients with HCC.
10.Effects of drought stress training on polysaccharide accumulation and drought resistance of Codonopsis pilosula.
Lu-Lu WANG ; Xiao-Lin WANG ; Zhe-Yu LIU ; Li-Zhen WANG ; Jia-Tong SHI ; Jiao-Jiao JI ; Jian-Ping GAO ; Yun-E BAI
China Journal of Chinese Materia Medica 2025;50(3):672-681
In order to clarify the effects of drought stress training on the quality and drought resistance of Codonopsis pilosula, this study used PEG to simulate drought stress and employed potting with water control for the drought stress training of C. pilosula plants. The polysaccharide content, secondary metabolites, antioxidant system, and photosynthetic pigment system of C. pilosula after drought stress training were analyzed. The results showed that the content of fructans in the root of C. pilosula increased after two rounds of drought stress treatment, and it was significantly higher than that of the control group. The accumulation of fructans in the root of C. pilosula showed an upward trend during the rehydration treatment. The content of lobetyolin and tangshenoside Ⅰ increased after drought stress treatment compared with that of the control group. The rehydration treatment caused first increasing and then decreasing in the content of lobetyolin, while it had no significant effect on the tangshenoside Ⅰcontent. The content of photosynthetic pigments decreased after drought stress treatment, and it gradually increased during the first round of rehydration and the second round of rehydration. Moreover, the increase was faster in the second round of rehydration than in the first round of rehydration. The content of the peroxidation product malondialdehyde(MDA) and the activities of superoxide dismutase(SOD), peroxidase(POD), and catalase(CAT) increased after drought stress treatment compared with those of the control group, and they showed a tendency of decreasing during rehydration. Moreover, the decrease was faster in the second round of rehydration than in the first round of rehydration. When the plants of C. pilosula after drought stress training were again subjected to severe drought stress, the wilting rate decreased significantly, and the biomass increases significantly. This study showed that the drought stress training could promote the accumulation of polysaccharides and secondary metabolites in the root of C. pilosula. When encountering drought stress again, C. pilosula plants could quickly regulate the antioxidant system and delay the decomposition of chlorophyll to respond to drought stress. The findings provide a theoretical basis for the ecological cultivation of C. pilosula in arid and semi-arid areas.
Codonopsis/growth & development*
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Droughts
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Polysaccharides/metabolism*
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Stress, Physiological
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Water/metabolism*
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Antioxidants/metabolism*
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Photosynthesis
;
Drought Resistance

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