INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
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2025
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IF 8.5
Hengrui Liu,Xiaorong Yang
L-DOPA (3,4-dihydroxyphenyl-L-alanine) is a key drug for the Parkinson's disease. The global demand of L-DOPA is continuously increasing. Tyrosine phenol-lyase (TPL) is the environmentally friendly biocatalyst for L-DOPA biosynthesis. In this study, a novel TPL from Mycobacterium tuberculosis (Mt-TPL) was identified and expressed in Escherichia coli . The characterization of Mt-TPL indicated that the optimal temperature and pH values were 40 °C and 9.0, respectively, and the half-lives (t 1/2 ) at 30 °C were 6.52 h. To further improve its catalytic performance, protein engineering of Mt-TPL was undertaken using a consensus sequence-based strategy. It was found that the I384V mutant exhibited the increase of 40.31 % in the enzymatic activity as compared with the wild-type enzyme. Molecular docking and molecular dynamics (MD) simulations revealed that the I384V mutation changed the local flexibility of enzyme and the orientation of substrate, and shortened the proton transfer distance between the generic acid Y71 and substrate pyrocatechol. Finally, the whole-cell catalysts with wild type and I384V Mt-TPL were used to product the L-DOPA, the L-DOPA production of 95.46 g/L for whole-cells with I384V Mt-TPL was achieved in a 5 L fermenter by the fed-batch, 38.6 % higher than that of the wild type enzyme.
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高影响因子
FISH & SHELLFISH IMMUNOLOGY
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2024
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IF 4.1
Ting Yu,Meng Xie,Kai Luo,Xiao Zhang,Weihua Gao,Qiaoqing Xu,Shuhuan Zhang
IFN-γ plays a crucial role in both innate and adaptive immune responses and is a typical Th1 cytokine that promotes Th1 response and activates macrophages. When macrophages were incubated with IFN-γ, their phagocytosis ratio against Mycobacterium marinum increased significantly, as observed under fluorescence microscopy. The macrophages engulfed a large number of M. marinum . The proliferative ability of macrophages treated with IFN-γ was significantly weaker on the 4th and 7th day after phagocytosis and subsequent re-infection with marine chlamydia (P < 0.001). This suggests that IFN-γ enhances the phagocytosis and killing ability of macrophages against M. marinum . IFN-γ protein also significantly increased the production of reactive oxygen species (H 2 O 2 ) and nitric oxide (NO) by macrophages. Additionally, the expression levels of toll-like receptor 2 ( tlr2 ) and caspase 8 ( casp8 ) were significantly higher in macrophages after IFN-γ incubation compared to direct infection after 12 h of M. marinum stimulation. Apoptosis was also observed to a higher degree in IFN-γ incubated macrophage. Moreover, mRNA expression of major histocompatibility complex (MHC) molecules produced by macrophages after IFN-γ incubation was significantly higher than direct infection. This indicates that IFN-γ enhances antigen presentation by upregulating MHC expression. It also upregulates tlr2 and casp8 expression through the TLR2 signaling pathway to induce apoptosis in macrophages. The pro-inflammatory cytokine showed an initial increase followed by a decline, suggesting that IFN-γ enhances the immune response of macrophages against M. marinum infection. On the other hand, the anti-inflammatory cytokine showed a delayed increase, significantly reducing the expression of pro-inflammatory cytokines. The expression of both cytokines balanced each other and together regulated the inflammatory reaction against M. marinum infection.
研究领域:
免疫学
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微生物学
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分子生物学
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细胞生物学
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Frontiers in Cellular and Infection Microbiology
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2025
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IF 4.8
Yihui Xie,Zhaoqin Zhu,Yuxin Shi,Zihui Zhao,Xueqin Qian,Yinzhong Shen
Objective The BACTEC MGIT 960 system is currently the most widely used rapid culture system for Mycobacterium tuberculosis . However, its reagents have complex compositions, expensive, and rely on import. This study aimed to develop a self-formulated culture with simple composition, low cost, and performance comparable to or even better than that of the BACTEC MGIT 960 system. Methods Five experimental media were formulated by supplementing Sauton medium with carrot extract, potato extract, oleic acid, or choline chloride. These were compared against commercial MGIT 960 medium using M. tuberculosis H37Rv suspensions (10 - ³-10 -6 mg/mL, triplicate cultures). Time to detection (TTD) and growth index (GI) were monitored automatically using the BACTEC MGIT 960 system. Results For medium-high inocula (10 - ³-10 -5 mg/mL), carrot- and potato-supplemented Sauton media showed equivalent performance to MGIT 960 (1-day longer TTD, P>0.05; comparable GI values). At low inoculum (10 -6 mg/mL), MGIT 960 failed to detect growth within 42 days, whereas supplemented Sauton medium achieved positivity within 30 days. The carrot extract medium performed best (mean TTD = 20.2 days), followed by oleic acid and oleic acid + choline chloride formulations. Conclusion Carrot- and potato-supplemented Sauton medium demonstrated comparable performance to the MGIT 960 system for specimens with medium-to-high bacterial loads. Carrot extract, oleic acid, and choline chloride significantly enhanced the detection rate of low-inoculum, with carrot extract exhibiting the most pronounced growth-promoting effects. This study validates an accessible alternative to expensive imported media, particularly beneficial for resource-limited settings.
研究领域:
微生物学
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临床检验科学
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结核病研究
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诊断方法
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JOURNAL OF INTERFERON AND CYTOKINE RESEARCH
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2016
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IF 2.135
Wu Li,Minqiang Liu,Jianping Xie
The pathogenesis of tuberculosis, caused by Mycobacterium tuberculosis, is largely because of the pathogen's successful entry and survival within macrophages. We predicted that rv3369, a gene encoding a conserved protein, might play a role in the interactions with host cells. To test this, rv3369 gene was heterologously expressed in a nonpathogenic fast-growing Mycobacterium smegmatis strain. The recombinant strain survives better than the control within macrophages, accompanied by more host cell death and a marked higher secretion of interleukin-1β (IL-1β). Furthermore, pharmacological inhibition experiments showed that the NF-κB and ERK pathways were involved in the Rv3369-triggered IL-1β changes. These results provided evidence for the engagement of Rv3369 in the interaction between mycobacteria and host.
研究领域:
微生物学
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免疫学
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感染病学
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分子生物学
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细胞生物学
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病原生物学
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ACS Sensors
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2019
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IF 6.944
Xiaoqing Zhang,Ye Feng,Shaoyun Duan,Lingling Su,Jialin Zhang,Fengjiao He
The accurate and rapid detection of Mycobacterium tuberculosis (M. tuberculosis) is essential for the effective treatment of tuberculosis. In this article, we propose an electrochemical sensor to detect M. tuberculosis reference strain H37Rv. The sensor contains an H37Rv aptamer and oligonucleotides modified with gold nanoparticles (AuNPs–DNA). An H37Rv aptamer screened by our laboratory was used as the recognition probe. The change in frequency shift mediated by AuNPs–DNA in the presence of H37Rv was detected using a multichannel series piezoelectric quartz crystal (MSPQC) system. Three oligonucleotides modified with gold nanoparticles were designed. These oligonucleotides contained 12, 12, and 13 bases that hybridized with the 37-nt H37Rv aptamer. H37Rv aptamer was immobilized on the gold electrode surface by Au–S bonds. A conductive-layer was then formed by sequential hybridization of the aptamer with the three designed AuNPs–DNAs. When H37Rv was present, it specifically bound to the aptamer, resulting in the detachment of AuNPs–DNA from the electrode. The conductive layer was thereby replaced by a nonconductive complex of aptamer and bacteria. These changes were monitored by the MSPQC system. The proposed sensor is rapid, specific and sensitive, the detection time was 2 h. The detection limit was 100 cfu/mL. This sensor would be of great benefit for the early clinical diagnosis of tuberculosis.
研究领域:
医学诊断
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生物传感器
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纳米技术
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ANALYTICA CHIMICA ACTA
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2020
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IF 5.977
Xin Yue,Yu Huang,Yu Zhang,Hui Ouyang,Jianping Xie,Zhifeng Fu
Mycobacterium tuberculosis ( M. tuberculosis ), the causative agent of tuberculosis, ranks one of the most dangerous pathogens for its large deaths toll. Due to its characteristic extremely slow growth, the conventional culture-based protocol cannot meet the requirement for the efficient diagnosis of M. tuberculosis -induced tuberculosis. With our previously isolated mycobacteriophage SWU1, we tried to develop a mycobacteriophage-based protocol for detecting Mycobacterium genus. In this work, Mycobacterium smegmatis ( M. smegmatis ) was used as a model due to its similar physiological features as pathogenic M. tuberculosis , much faster growth and nonpathogenic property. Mycobacteriophage SWU1-functionalized magnetic particles (SWU1-MPs) were used as highly efficient separation carriers for the viable host M. smegmatis . After a replication cycle of approximate 60 min, the cells of M. smegmatis were disrupted by the progeny mycobacteriophages to release intracellular adenosine triphosphate (ATP). The bioluminescent (BL) signal of released ATP was collected to quantitate the amount of M. smegmatis . For the developed protocol, the detection range is 5.0 × 10 2 to 5.0 × 10 5 CFU mL −1 , and the detection limit is 3.8 × 10 2 CFU mL −1 ( S / N = 3). Furthermore, the protocol can exclude the potential interference of 3 non-pathogenic mycobacteria and 6 other bacterial species. It has been successfully applied to quantitate M. smegmatis in human urine, human saliva, and human serum. The results demonstrate its application potential for a simple, fast, and specific diagnosis of M. tuberculosis infection.
研究领域:
医学微生物学
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分子诊断学
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PubMed
高影响因子
MOLECULES
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2022
·Vol. 27
·期 17
·5691
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IF 4.927
Lan Luo,Xuemei Song,Xiao Chang,Sheng Huang,Yunxi Zhou,Shengmei Yang,Yan Zhu,Lanyan Zhang,Yongsheng Wu,Junyin Zhang,Zhipeng Zhou,Mingyi Wu
Bacillus Calmette-Guérin polysaccharide and nucleic acid (BCG-PSN), extracted fromMycobacterium bovis, is an immunoregulatory medicine commonly used in clinic. However, the structural characteristics and potential pharmacological efficacy of the polysaccharides from BCG-PSN remain unclear. Herein, two polysaccharides (BCG-1 and BCG-2) were purified and their structures were characterized. Monosaccharide composition analysis combined with methylation analysis and NMR data indicated that BCG-1 and BCG-2 were an α-D-(1→4)-mannan with (1→2)-linked branches, and an α-D-(1→4)-glucan with (1→6)-linked branches, respectively. Herein, the mannan from BCG-PSN was first reported. Bioactivity assays showed that BCG-1 and BCG-2 dose-dependently and potently increased the production of inflammatory mediators (NO, TNF-α, IL-6, IL-1β, and IL-10), as well as their mRNA expressions in RAW264.7 cells; both have similar or stronger effects compared with BCG-PSN injection. These data suggest that BCG-1 and BCG-2 are very likely the active ingredients of BCG-PSN.Keywords:active ingredients;polysaccharide purification;glucan;mannan;immunomodulator
研究领域:
免疫学
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药理学
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生物化学
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Foods
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2021
·Vol. 10
·期 11
·2819
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IF 4.35
Huibing Chi,Meirong Chen,Linshu Jiao,Zhaoxin Lu,Xiaomei Bie,Haizhen Zhao,Fengxia Lu
L-asparaginase (E.C.3.5.1.1) is a well-known agent that prevents the formation of acrylamide both in the food industry and against childhood acute lymphoblastic leukemia in clinical settings. The disadvantages of L-asparaginase, which restrict its industrial application, include its narrow range of pH stability and low thermostability. In this study, a novel L-asparaginase fromMycobacterium gordonae(GmASNase) was cloned and expressed inEscherichia coliBL21 (DE3). GmASNase was found to be a tetramer with a monomeric size of 32 kDa, sharing only 32% structural identity withHelicobacter pyloriL-asparaginases in the Protein Data Bank database. The purified GmASNase had the highest specific activity of 486.65 IU mg−1at pH 9.0 and 50 °C. In addition, GmASNase possessed superior properties in terms of stability at a wide pH range of 5.0–11.0 and activity at temperatures below 40 °C. Moreover, GmASNase displayed high substrate specificity towards L-asparagine with Km, kcat, and kcat/Km values of 6.025 mM, 11,864.71 min−1and 1969.25 mM−1min−1, respectively. To evaluate its ability to mitigate acrylamide, GmASNase was used to treat potato chips prior to frying, where the acrylamide content decreased by 65.09% compared with the untreated control. These results suggest that GmASNase is a potential candidate for applications in the food industry.Keywords:L-asparaginase;acrylamide;Mycobacterium gordonae;thermal stability
研究领域:
食品科学
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酶学
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生物技术
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生物化学
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iScience
·
2025
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IF 4.1
Pan Liu,Jiezhong Deng,Yusheng Yang,Wenxi Bai,Shengtao Dong,Zehua Zhang
Tuberculosis (TB), caused by Mycobacterium tuberculosis ( M.tb ), is one of the most ancient diseases recorded. In cases of bone TB, it significantly disrupts bone homeostasis, though the precise mechanisms are poorly understood and effective treatment targets are scarce. Our study investigated the role of Rv1509 in the pathogenesis of bone TB. We found that Rv1509 enhances the differentiation of bone marrow macrophages (BMMs) into osteoclasts by activating the TLR2 pathway, which stimulates the production of IL-6 and TNF-α. This, in turn, indirectly inhibits osteoblast differentiation and mineralization. Additionally, Rv1509 directly impairs osteoblast function and enhances the secretion of RANKL via TLR2 signaling, creating a detrimental RANKL/OPG imbalance that promotes osteoclast differentiation and bone degradation. Notably, the injection of Rv1509 into mouse skulls led to extensive bone damage, highlighting its significant role as a virulence factor in the pathogenesis of bone TB.
研究领域:
免疫学
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微生物学
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骨骼生物学
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MOLECULAR DIVERSITY
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2026
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IF 4.3
Li Hongfu,Zhao Likun,Liu Zixin,Du Zhenzhen,Xie Jianhong,Huang Mingxing,Huang Huitao,Chan Hongtou,Zhao Yijie,Tong Henry H. Y.,Yao Xiaojun,Liu Huanxiang,Zhang Qianqian
Mycobacterium tuberculosis ( Mtb ) remains one of the deadliest pathogens worldwide, further complicated by the increasing prevalence of multidrug-resistant (MDR) and extensively drug-resistant strains. In this study, a structure-based virtual screening workflow was employed to repurpose approved drugs from the DrugBank database for six essential Mtb targets: InhA, MmpL3, DprE1, QcrB, GyrB, and LeuRS. Systematic evaluation of protein conformations followed by hierarchical docking and Prime MM-GBSA rescoring yielded 30 candidate compounds for biological testing. Among them, Ozenoxacin, Epirubicin, Idarubicin, Mitoxantrone, and Tosufloxacin showed significant antimycobacterial activity against the H37Rv strain, with Ozenoxacin exhibiting the strongest activity. Ozenoxacin, Epirubicin, and Idarubicin also retained in vitro activity against the tested MDR clinical isolate, and Ozenoxacin further showed additive interactions with rifampicin, isoniazid, ethambutol, and streptomycin, without detectable antagonism. Time-kill assays demonstrated that Ozenoxacin produced a clear dose-dependent delay in bacterial growth in both H37Rv and MDR strains, supporting its sustained growth-inhibitory effect. Molecular docking and molecular dynamics simulations further suggested plausible binding modes of Ozenoxacin and Epirubicin in GyrB and of Idarubicin in DprE1, providing structural hypotheses for their possible target interactions. Overall, these findings suggest that Ozenoxacin and several other active compounds warrant further investigation as potential repurposing candidates against Mtb .
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Advanced Science
·
2026
·
IF 14.1
Lingzhi Chen,Jiaqi Yu,Jing Xu,Lingqi Chen,Ninghao Zhang,Wenrui Li,Runmin Zeng,Xiaomin Luo,Yiqun Chang,Jiayin Lai,Wenshi Huang,Xiaochen Liang,Ting Zhao,Shanze Chen,Huaihong Cai,Yanguang Cong,Pinghua Sun,Jiang Pi,Xueqin Huang,Haibo Zhou,Junxia Zheng
Rapid and sensitive diagnostic strategies are crucial for the prevention and control of tuberculosis (TB). Unlike the invasive TB diagnostic strategy in the clinic, here we introduce a convenient, portable, and non-invasive system that is constructed by Ag@Au nanoflower (NF) array-based sensing facemask and catalytic/plasmonic urchin-shaped Au─Ag embedded covalent organic framework (U@COF) sensor. This system detects TB antigen ESAT-6/CFP-10 complex in droplet or sputum samples from a variety of clinical settings. Practical analysis of clinical samples demonstrates this assay is capable of classifying the negative ( N = 12 ) and positive ( N = 17 ) TB patients with satisfactory sensitivity (76.5%) and specificity (100%), among whom two TB-infected patients (TB3 and TB5) missed by droplet analysis are successfully identified by sputum analysis. More importantly, two cases with abnormally elevated ESAT-6/CFP-10 levels are screened out from close contacts of TB patients ( N = 6 ), which is highly suggestive of TB infection (Close contacts 3 and 4). This portable mask is suitable for rapid diagnosis of TB infection in patients with cough, particularly for screening of TB close contacts.
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Antibiotics-Basel
·
2024
·Vol. 13
·期 3
·278
·
IF 4.3
Chun Wang,Yun-Yao Ren,Li-Mei Han,Peng-Cheng Yi,Wei-Xiao Wang,Cai-Yun Zhang,Xiu-Zhen Chen,Ming-Zhe Chi,Apeng Wang,Wei Chen,Chun-Mei Hu
Antimicrobial peptides (AMPs) hold promise as alternatives to combat bacterial infections, addressing the urgent global threat of antibiotic resistance. COG1410, a synthetic peptide derived from apolipoprotein E, has exhibited potent antimicrobial properties against various bacterial strains, includingMycobacterium smegmatis. However, our study reveals a previously unknown resistance mechanism developed byM. smegmatisagainst COG1410 involving ClpC. Upon subjectingM. smegmatisto serial passages in the presence of sub-MIC COG1410, resistance emerged. The comparative genomic analysis identified a point mutation in ClpC (S437P), situated within its middle domain, which led to high resistance to COG1410 without compromising bacterial fitness. Complementation of ClpC in mutant restored bacterial sensitivity. In-depth analyses, including transcriptomic profiling and in vitro assays, uncovered that COG1410 interferes with ClpC at both transcriptional and functional levels. COG1410 not only stimulated the ATPase activity of ClpC but also enhanced the proteolytic activity of Clp protease. SPR analysis confirmed that COG1410 directly binds with ClpC. Surprisingly, the identified S437P mutation did not impact their binding affinity. This study sheds light on a unique resistance mechanism against AMPs in mycobacteria, highlighting the pivotal role of ClpC in this process. Unraveling the interplay between COG1410 and ClpC enriches our understanding of AMP-bacterial interactions, offering potential insights for developing innovative strategies to combat antibiotic resistance.
研究领域:
微生物学
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药理学
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分子生物学
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高影响因子
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