Parasites & Vectors
·
2025
·Vol. 18
·期 1
·1-15
·
IF 3.5
Geng Xiao-Ling,Li Jing-Yu,Xu Huan-Yu,Wu Jiang-Ping,Tao De-Liang,Chen Jin-Ming,Fan Ying-Ying,Yang Xin,Song Jun-Ke,Zhao Guang-Hui
Background The pathogenicity of Toxoplasma gondii is closely associated with its intracellular lytic cycle in host cells. Currently, the mechanisms by which T. gondii completes the lytic cycle remain unclear. The proline metabolism has been reported to be crucial for intracellular growth of pathogens by providing energy and nutrients. However, it remains unclear whether the intracellular growth and pathogenicity of T. gondii are related to proline metabolism.Methods The gene-edited strains of proline dehydrogenase (Tgprodh) were constructed by using clustered regularly interspaced short palindromic repeats/CRISPR-associated protein 9 (CRISPR–Cas9) technology. The effects of the Tgprodh gene on the growth in vitro and pathogenicity in vivo of the tachyzoites for T. gondii were studied through proliferation, plaque, invasion, egress and virulence assays. The effects of the Tgprodh gene on mitochondrial function were studied by using reactive oxygen species (ROS), mitochondrial membrane potential (∆Ψm), adenosine triphosphate (ATP) assay kits, mitochondrial DNA (mtDNA) copy numbers, transmission electron microscopy (TEM) analysis, and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR). The effects of the Tgprodh gene on proline metabolism were studied by using l-proline (L-Pro), l-glutamic acid (L-Glu), l-glutamine (L-Gln) assay kits, and RT-qPCR.Results TgPRODH, the first rate-limiting enzyme in proline metabolism, was identified to be encoded by T. gondii and localized in the cytoplasm of T. gondii. Deletion of the Tgprodh gene resulted in significant growth inhibition in vitro and reduced pathogenicity in vivo of T. gondii. Further study found that deletion of the Tgprodh gene caused damage to the mitochondrial morphology, decreased membrane potential, mtDNA copy numbers, and the production of ATP and ROS. The expression of genes for maintaining mitochondrial integrity was downregulated in the Tgprodh-knockout strain of T. gondii, while complementation of the Tgprodh gene restored these defects in this parasite. Meantime, the deletion of the Tgprodh gene resulted in the accumulation of proline, reduced the contents of glutamate and glutamine, and affected the expression of genes related to proline catabolism in T. gondii.Conclusion sThe present study found the significance of the Tgprodh gene for the intracellular growth and pathogenicity of T. gondii through regulating mitochondrial function and the proline metabolism and provided a novel insight to reveal intracellular survival strategies of T. gondii.Graphical
研究领域:
寄生虫学
·
微生物学
·
分子生物学
·
细胞生物学
·
遗传学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Toxics
·
2023
·Vol. 11
·期 10
·803
·
IF 4.6
Chengzhi Li,Yuxi Feng,Peng Tian,Xiaozhang Yu
The accumulation of proline impacts the defense mechanisms of plants against the harmful effects of adverse environmental conditions; however, its concentration in plants is associated with the metabolism of N. Therefore, the effects of exogenous organic [glutamate (Glu)/arginine (Arg)] and inorganic [nitrate (NO3−)/ammonium (NH4+)] N on the accumulation of proline (Pro) in rice plants under trivalent chromium [Cr(III)] stress were studied through using the mass balance matrix model (MBMM). Application of ‘NH4+’ showed the largest contribution to the Pro content in rice shoots under different concentrations of Cr(III), followed by ‘NO3−’, ‘Arg’, and ‘Glu’ applications. On the other hand, ‘Arg’ application displayed the largest contribution to the Pro content in roots under Cr(III) stress, followed by ‘NH4+’, ‘Glu’, and ‘NO3−’ applications. The combined application of ‘NH4++Arg’ showed the greatest contribution to the Pro content in both roots and shoots of Cr(III)-treated rice seedlings, while the application of ‘NO3−+Glu’ showed the least contribution to the Pro content in rice seedlings. The current study indicated that the endogenous level of Pro in rice seedlings is quite sensitive to Cr(III) stress under different N sources, and the mathematical modeling showed a reliable result while estimating the relationship between Pro content and N source application.Keywords:proline;rice;trivalent chromium;nitrogen source;mass balance
研究领域:
植物生理学
·
环境科学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF FOOD PROCESSING AND PRESERVATION
·
2021
·Vol. 45
·期 10
·e15821
·
IF 2.19
Qun Huang,Hanliang Song,Yonggui Pan,Zhengke Zhang
Papaya fruit is easily affected by low temperature, causing chilling injury (CI). In this study, the exogenous arginine was applied in the storage of postharvest papaya fruit and it was found that 0.8 mM arginine treatment significantly alleviated CI of papaya fruit. Arginine treatment promoted the accumulation of polyamines (PAs), which might be ascribed to the increased activities of arginase, arginine decarboxylase (ADC), ornithine decarboxylase (ODC), and S-adenosylmethionine decarboxylase (SAMDC). A higher accumulation of proline was found in arginine-treated papaya fruit, which may be due to increased activity of ornithine-δ-aminotransferase (OAT) and Δ 1 -pyrroline-5-carboxylate acid synthase (P5CS) and inhibited activity of proline dehydrogenase (PDH). In addition, arginine treatment increased higher nitric oxide synthase (NOS) activity and promoted the generation of nitric oxide (NO). The results of this study indicate that exogenous arginine may improve the chilling tolerance of postharvest papaya fruit by regulating arginine and proline metabolism. Practical applications In recent years, chilling injury of tropical fruits is a significant problem, including papaya. Many studies on polyamine, proline, nitric oxide, and chilling injury of fruits, but arginine, as a common precursor of polyamine, proline, and nitric oxide, are rarely studied, especially in papaya fruit. Our findings demonstrated that the exogenous arginine can regulate endogenous arginine metabolism, induce polyamine, putrescine, and nitric oxide accumulation, and coordinate to alleviate chilling injury of papaya fruit.
研究领域:
植物生理学
·
园艺学
✓ 已验证
产品关联
DOI
高影响因子
FOOD CHEMISTRY
·
2024
·
IF 8.5
Yejun Zhang,Yongzhen Wang,Hao Dong,Jiao Li,Jianan Sun,Xiangzhao Mao
Temperature fluctuations can negatively affect the quality of frozen shrimp. Research on novel cryoprotectants to replace traditional agents (phosphate, etc.) has become a hotspot. Our results indicated that L-Proline could reduce thawing losses, delay texture deterioration and improve the functional properties of myofibrillar proteins of shrimp. Thawing loss in the proline group (3.2 %) was significantly lower than that in the control (5.4 %) after 3 freeze-thaw cycles ( p < 0.05). Compared to Na 4 P 2 O 7 , proline had better permeability and greater ability to inhibit ice crystal growth and volume expansion. Through molecular simulations, we found that proline might inhibit ice crystal formation by forming glassy states with water. Hydrogen bonding between proline and water/ice played a major role, and only a small amount of proline was required to significantly reduce the ice crystal growth rate from 0.16 m/s to 0.06 m/s. Briefly, proline exhibited potential as a cryoprotectant for shrimp in temperature fluctuations.
研究领域:
食品科学
·
分子生物学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF PLANT PHYSIOLOGY
·
2024
·
IF 4
Miao Sun,Huan-Xuan Qiao,Tao Yang,Peng Zhao,Jun-Hao Zhao,Jia-Ming Luo,Hai-Ye Luan,Xiang Li,Sheng-Cai Wu,Ai-Sheng Xiong
Carrot ( Daucus carota L.), a widely cultivated economically vegetable from the Apiaceae family, is grown globally. However, carrots can be adversely impacted by cadmium (Cd) pollution in the soil due to its propensity to accumulate in the fleshy root, thus impeding carrot growth and posing health hazards to consumers. Given the potential of hydrogen sulfide (H 2 S) to improve plant resistance against Cd stress, we treated germinating carrot seeds with varying concentrations of sodium hydrosulfide (NaHS), aiming to alleviate the toxic impacts of Cd stress on carrot seed germination. The results revealed that carrot seeds treated with a concentration of 0.25 mM NaHS displayed better seed germination-associated characteristics compared to seeds treated with NaHS concentrations of 0.1 mM and 0.5 mM. Further investigation revealed a rise in the expression levels of L-cysteine desulfhydrase and D-cysteine desulfhydrase , along with enhanced activity of L-cysteine desulfhydrase and D-cysteine desulfhydrase among the NaHS treatment group, thereby leading to H 2 S accumulation. Moreover, NaHS treatment triggered the expression of pyrroline-5-carboxylate synthase and pyrroline-5-carboxylate reductase and promoted the accumulation of endogenous proline, while the contents of soluble sugar and soluble protein increased correspondingly. Interestingly, since the application of exogenous proline did not influence the accumulation of endogenous H 2 S, suggesting that H 2 S served as the upstream regulator of proline. Histochemical staining and biochemical indices revealed that NaHS treatment led to elevated antioxidant enzyme activity, alongside a suppression of superoxide anion and hydrogen peroxide generation. Furthermore, high performance liquid chromatography analysis revealed that NaHS treatment reduced Cd 2+ uptake, thereby promoting germination rate, seed vitality, and hypocotyl length of carrot seeds under Cd stress. Overall, our findings shed light on the application of NaHS to enhance carrot resistance against Cd stress and lay a foundation for exploring the regulatory role of H 2 S in plants responding to Cd stress.
研究领域:
植物学
·
环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMOSPHERE
·
2016
·
IF 3.698
Lina Zhou,Mengjie Xia,Li Wang,Hui Mao
As a persistent organic pollutant in the environment, perfluorooctanoic acid (PFOA) has been extensively investigated. It can accumulate in food chains and in the human body. This work investigated the effect of PFOA on wheat ( Triticum aestivum L.) germination and seedling growth by conducting a germination trial and a pot trial. A stimulatory effect of PFOA on seedling growth and root length of wheat was found at <0.2 mg kg −1 , while >800 mg kg −1 PFOA inhibited germination rate, index, and root and shoot growth. In the pot trial, PFOA concentration in root was double that in the shoot. Soil and plant analyzer development (SPAD) and plant height of wheat seedling were inhibited by adding 200 mg kg −1 PFOA. Proline content and POD activity in wheat seedlings increased as PFOA increased, while CAT activity decreased. Using logarithmic equations, proline content was selected as the most sensitive index by concentration for 50% of maximal effect (EC 50 ). Hence, the tolerance of wheat seedlings to PFOA levels could be evaluated on the basis of the physiological index.
研究领域:
环境科学
·
植物生理学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Analytical Methods
·
2015
·Vol. 7
·期 18
·7625-7630
·
IF 1.821
Yi Li,Jinhui Zhou,Xiaofeng Xue,Liming Wu,Lanzhen Chen,Jinzhen Zhang,Shuming Yang
An optimization method of NBD-F derivatization has been developed for the determination of proline in honey using high performance liquid chromatography (HPLC) with fluorescence detection. To determine the free proline in different samples of honey, ultrasound extraction was performed using 0.1 M borate buffer solution as the extraction solvent. Chromatographic separation was performed on a XDB C18 column (150 × 4.6 mm i.d.) using 0.1 M sodium acetate buffer solution (pH 7.2) : methanol : tetrahydrofuran (900 : 95 : 5, respectively, v/v/v) as mobile phase A and methanol as mobile phase B at a flow rate of 1.0 mL min−1 with a run time of 10 min. The assay was linear over a range of 0.15 μg mL−1 to 100.00 μg mL−1 with a lower limit of detection of 3.00 mg kg−1, and recoveries were greater than 90%. The intra-day and inter-day precision was less than 4%. This method was successful in determining free proline in honey, ranging from 80.5 mg kg−1 to 426.4 mg kg−1 in different honey samples.
研究领域:
分析化学
·
食品科学
✓ 已验证
DOI
高影响因子
GREEN CHEMISTRY
·
2020
·Vol. 22
·期 13
·4222-4230
·
IF 9.48
Jiayuan Yu,Anker Degn Jensen,Lei Wang,Chunshan Li,Suojiang Zhang
Methacrolein (MAL) is an important chemical for the manufacture of methyl methacrylate and a key monomer in many polymerization reactions. In this study, L-proline was investigated as the catalyst for the aldol condensation of formaldehyde and propionaldehyde to produce MAL. The catalytic activity of the reaction system was closely related to the competition between the main reaction synthesizing MAL and the side reaction producing 2-methyl-2-pentenal, which could be modified by adjusting the operating parameters. The influences of several operating conditions, including temperature, reaction time and water content, on the catalytic performance of the system were systematically studied via a series of single-factor experiments, and the optimized reaction conditions were obtained. The mechanistic investigation via ESI-MS indicated that the reaction pathway followed the Mannich route. Experimental and theoretical kinetic analyses of the L-proline-catalyzed aldol condensation reaction were performed, and the reaction orders of the reactants were obtained by regression. The results showed that L-proline was an efficient catalyst for the production of MAL via aldol condensation under mild conditions.
研究领域:
化学工程
·
有机化学
✓ 已验证
产品关联
DOI
高影响因子
Catalysts
·
2021
·Vol. 12
·期 1
·42
·
IF 4.146
Longxin Ju,Gang Li,Hongxian Luo
Aldol condensation reactions are very important C–C coupling reactions in organic chemistry. In this study, the catalytic performance of layered double hydroxides (LDHs) in the aldol condensation reaction of formaldehyde (FA) and propionaldehyde (PA) was investigated. The MxAl-LDHs (denoted as re-MxAl–LDHs; M = Ca and Mg; X = 2–4), as heterogeneous basic catalysts toward the aldol condensation reaction, were prepared via a two-step procedure. The catalyst exhibited a high PA conversion (82.59%), but the methacrolein (MAL) selectivity was only 36.01% due to the limitation of the alkali-catalyzed mechanism. On this basis, the direct intercalation of L-proline into LDHs also has been investigated. The influences of several operating conditions, including the temperature, reaction time, and substrate content, on the reaction results were systematically studied, and the optimized reaction conditions were obtained. The optimized Mg3Al–Pro-LDHs catalyst exhibited a much higher MAL selectivity than those of re-MgxAl–LDHs.Keywords:layered double hydroxides;L-proline;aldol condensation reaction
研究领域:
有机化学
·
催化材料科学
✓ 已验证
产品关联
DOI
高影响因子
Fermentation-Basel
·
2025
·Vol. 11
·期 4
·168
·
IF 3.3
Yiyan Zhang,Xiongyao Ma,Zhe Xu,Xiangyu Gu,Xiangyang Gu
Lycopene is a natural carotenoid with antioxidation properties. The objective of the present study was to investigate the roles of glutamate and proline in lycopene biosynthesis in a newly isolated purple non-sulfur bacteriumCereibacter sphaeroidesDT.1, under aerobic conditions. This strain contained a distinct CrtI4capable of converting phytoene to lycopene via four-step desaturation. In order to enhance lycopene production, acrtCknockout mutant was constructed via homologous recombination. Supplementation with glutamate or proline to fermentative medium significantly enhanced intracellular lycopene accumulation in wildtype strain by a respective 99.40 ± 0.54% and 101.70 ± 0.49% and in aΔcrtCmutant strain by 38.13 ± 0.15% and 39.83 ± 0.27%, respectively. Differential transcriptomic and metabolomic analyses showed that these promoting effects were associated with downregulation of the expression of the acyclic carotenoid 1,2-hydratase gene, and increased accumulation of lycopene precursors such as pyruvate and acetyl-CoA. The fermentation conditions for lycopene production were optimized through shake flask experiments. Feasibility for lycopene production was confirmed in a fed-batch cultivation process and a high yield of 151.10 ± 0.13 mg/L was achieved. ThisΔcrtCmutant strain exhibited advantages, such as relatively lower oxygen demand and no need for illumination, making it a potentially useful strain for lycopene production under aerobic conditions.
研究领域:
微生物学
·
生物化学
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
·
2019
·
IF 3.372
Yangyang Bian,Hui Li,Shufeng Shen
Water-lean absorbents have potential applications for energy-efficient CO 2 capture. In this work, the chemical kinetics of the reaction between carbon dioxide (CO 2 ) and potassium prolinate (ProK) in ethanol, ethylene glycol and water solvents was measured in a stirred cell reactor with a stable gas-liquid interface at temperatures from 275.2 to 285.2 K and ProK molar concentrations up to 2.0 M. The experiments were performed under the pseudo-first-order regime to determine the overall kinetic rate constant ( k ov ) using two-film theory. The results showed that the reaction rates in each polar solvent increase considerably as the increasing ProK concentrations and temperatures. The reaction order was found to be in the range of 1.4–2.0 with respect to ProK concentration, depending on the solvents used. The kinetic results for the reaction in ethanol were also interpreted based on zwitterion mechanism and termolecular mechanism. The calculated from the two proposed models match well with the experimental data.
研究领域:
化学工程
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
International Journal of Chemical Engineering
·
2014
·
IF 0
Hu Li,Song Yang
L-Proline derived ionic liquids (ILs) used as both solvent and catalyst were efficient for transformation of fructose and sucrose to 5-hydroxymethylfurfural (HMF) in the presence of water. Response surface methodology (RSM) was employed to optimize fructose dehydration process, and a maximum HMF yield of 73.6% could be obtained at 90°C after 50 min. The recycling of the IL exhibited an almost constant activity during five successive trials, and a possible reaction mechanism for the dehydration of fructose to HMF was proposed.
研究领域:
化学工程
·
催化反应
✓ 已验证
产品关联
DOI
危险品化学品经营许可证（带存储）