المؤلفون: Yang, Ziyi^1,2 (AUTHOR), Wu, Wanling^1,2 (AUTHOR), Zhao, Qing^1,2 (AUTHOR), Angelidaki, Irini³ (AUTHOR), Arhin, Samuel Gyebi^1,2 (AUTHOR), Hua, Dongliang⁴ (AUTHOR), Zhao, Yuxiao⁴ (AUTHOR), Sun, Hangyu^1,2 (AUTHOR), Liu, Guangqing¹ (AUTHOR), Wang, Wen^1,2 (AUTHOR) wangwen@mail.buct.edu.cn

المصدر: Journal of Environmental Sciences (Elsevier). Sep2024, Vol. 143, p164-175. 12p.

مصطلحات موضوعية: SUCCINIC acid, LACTATE dehydrogenase, CARBON dioxide, CHEMICAL reactions, CHEMICAL equilibrium, LACTIC acid, CARBONATES

مستخلص: • Succinic acid production of 30 g/L was shown with 6 gC/L MgCO3 and 24 gC/L glucose. • The inorganic carbon of "carbonate:CO2 = 1:9″ presented the highest CO2 fixation. • The PEPCK/LDH was enhanced at high gaseous CO2, by promoting succinic acid path. • 50%−65% of inorganic carbon utilization was increased via stepwise CO2 addition. • 20%−30% increment in succinic acid selectivity was shown via stepwise CO2 addition. Utilizing CO 2 for bio-succinic acid production is an attractive approach to achieve carbon capture and recycling (CCR) with simultaneous production of a useful platform chemical. Actinobacillus succinogenes and Basfia succiniciproducens were selected and investigated as microbial catalysts. Firstly, the type and concentration of inorganic carbon concentration and glucose concentration were evaluated. 6 g C/L MgCO 3 and 24 g C/L glucose were found to be the optimal basic operational conditions, with succinic acid production and carbon yield of over 30 g/L and over 40%, respectively. Then, for maximum gaseous CO 2 fixation, carbonate was replaced with CO 2 at different ratios. The "less carbonate more CO 2 " condition of the inorganic carbon source was set as carbonate: CO 2 = 1:9 (based on the mass of carbon). This condition presented the highest availability of CO 2 by well-balanced chemical reaction equilibrium and phase equilibrium, showing the best performance with regarding CO 2 fixation (about 15 mg C/(L·hr)), with suppressed lactic acid accumulation. According to key enzymes analysis, the ratio of phosphoenolpyruvate carboxykinase to lactic dehydrogenase was enhanced at high ratios of gaseous CO 2 , which could promote glucose conversion through the succinic acid path. To further increase gaseous CO 2 fixation and succinic acid production and selectivity, stepwise CO 2 addition was evaluated. 50%-65% increase in inorganic carbon utilization was obtained coupled with 20%-30% increase in succinic acid selectivity. This was due to the promotion of the succinic acid branch of the glucose metabolism, while suppressing the pyruvate branch, along with the inhibition on the conversion from glucose to lactic acid. [Display omitted] [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Environmental Sciences (Elsevier) is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Zhou, Yufeng^1,2 (AUTHOR), Sun, Xiaolong¹ (AUTHOR), Hu, Jiahuan¹ (AUTHOR), Miao, Yingjie¹ (AUTHOR), Zi, Xiangyu^1,2 (AUTHOR), Luo, Xi¹ (AUTHOR) lxtzusols@163.com, Fu, Yongqian¹ (AUTHOR) bioengineer@163.com

المصدر: Journal of Biotechnology. Feb2024, Vol. 382, p1-7. 7p.

مصطلحات موضوعية: *LACTATE dehydrogenase, *CATALYST poisoning, *CATALYTIC activity, *ESCHERICHIA coli, *MOLECULAR docking, *CATALYSIS

مستخلص: Serving as a vital medical intermediate and an environmentally-friendly preservative, D-PLA exhibits substantial potential across various industries. In this report, the urgent need for efficient production motivated us to achieve the rational design of lactate dehydrogenase and enhance catalytic efficiency. Surprisingly, the enzymatic properties revealed that a mutant enzyme, Lr LDHT247I/D249A/F306W/A214Y (Lr LDH-M 1), had a viable catalytic advantage. It demonstrated a 3.3-fold increase in specific enzyme activity and approximately a 2.08-fold improvement of K cat. Correspondingly, molecular docking analysis provided a supporting explanation for the lower K m and higher K cat /K m of the mutant enzyme. Thermostability analysis exhibited increased half-lives and the deactivation rate constants decreased at different temperatures (1.47–2.26-fold). In addition, the mutant showed excellent resistance abilities in harsh environments, particularly under acidic conditions. Then, a two-bacterium (E. coli /pET28a- lrldh -M 1 and E. coli /pET28a- ladd) coupled catalytic system was developed and realized a significant conversion rate (77.7%) of D-phenyllactic acid, using 10 g/L L-phenylalanine as the substrate in a two-step cascade reaction. • A mutated lactate dehydrogenase Lr LDH-M 1 with a 3.3-fold enhancement in enzyme activity was obtained. • Enzymatic characterizations were carried out, and explained the enhanced enzyme activity with molecular docking analysis. • A two-bacterium coupled catalytic system was conducted to produce D-PLA from L-Phe with a high conversion rate (77.7%). [ABSTRACT FROM AUTHOR]

المؤلفون: Igwe, Chika Linda^1,2 (AUTHOR), Pauk, Jan Niklas^1,2 (AUTHOR), Hartmann, Thomas¹ (AUTHOR), Herwig, Christoph^1,2 (AUTHOR) christoph.herwig@lisalis.at

المصدر: Process Biochemistry. Jan2024, Vol. 136, p191-201. 11p.

مصطلحات موضوعية: *FINITE differences, *LACTATE dehydrogenase, *CELLULAR inclusions, *APPROXIMATION error, *PROTEINS

مستخلص: Development and optimization of inclusion body (IB) refolding processes is often based on empirical strategies. Thus, generation of in-depth process understanding is crucial to shift towards more knowledge-driven approaches. Within this contribution the goal was to establish a systematic approach for the reliable quantification of process dynamics in protein refolding processes. Established offline- analytical tools like HPLC-based methods or photometric assays were analyzed regarding their specifications and consequent suitability to quantify protein states. An in-silico study was conducted to define requirements for state quantification by analyzing the influences of error, discrete sampling intervals and the pace of the reaction on signal quality. Refolding and aggregation reaction rates were calculated by finite difference approximation with errors propagated from the corresponding folding state. Application of the defined principles on two real Lactate dehydrogenase fed-batch refolding processes resulted in two individual sampling strategies. At reaction rates of up to 0.58 g h−1 description of the ongoing dynamics could be done accurately with high sampling intervals during the first few hours of processing as shown by comparison to a noise free simulation. The proposed method has the potential to be transferred to other proteins and to facilitate the development of model-based monitoring & control strategies. [Display omitted] • Systematic selection of analytical tools for protein refolding states. • Analysis of influencing factors on signal quality of protein refolding and aggregation rates. • Quantitative analysis of folding dynamics in fed-batch refolding processes. • Sampling strategy for maximization of information via offline data generation. [ABSTRACT FROM AUTHOR]

المؤلفون: Yan, Kaihao¹ (AUTHOR), He, Qiwei¹ (AUTHOR), Lin, Dongni¹ (AUTHOR), Liang, Jianli¹ (AUTHOR), Chen, Junxiong¹ (AUTHOR), Xie, Zijing¹ (AUTHOR), Chen, Zhenzhou¹ (AUTHOR) chenzhenzhou@smu.edu.cn

المصدر: Free Radical Biology & Medicine. Nov2023, Vol. 208, p88-102. 15p.

مصطلحات موضوعية: *LACTATE dehydrogenase, *PROGENITOR cells, *ENDOTHELIAL cells, *CELLULAR aging, *NAD (Coenzyme), *HYPOXEMIA

مستخلص: Expansion of bone marrow-derived endothelial progenitor cells (EPCs) in vitro to obtain required cell numbers for therapeutic applications faces the challenge of growing cell senescence under the traditional normoxic culture condition. We previously found that 1% O 2 hypoxic culture condition is favorable for reducing senescence of EPCs, but the mechanisms underlying the favorability are still unclear. Here, we found that, compared with normoxia, hypoxia induced a shift in lactate dehydrogenase (LDH) isozyme profile, which manifested as decreased LDH2 and LDH1 and increased LDH5, LDH4 and total LDHs. Moreover, under hypoxia, EPCs presented higher LDH activity, which could promote the conversion of pyruvate to lactate, as well as a higher level of NAD+, Bcl2 interacting protein 3 (BNIP3) expression and mitophagy. Additionally, under hypoxia, knock-down of the LDHA subunit increased the LDH2 and LDH1 levels and knock-down of the LDHB subunit increased the LDH5 level, while the simultaneous knock-down of LDHA and LDHB reduced total LDHs and NAD+ level. Inhibition of NAD+ recycling reduced BNIP3 expression and mitophagy and promoted cell senescence. Taken together, these data demonstrated that 1% O 2 hypoxia induces a shift in the LDH isozyme profile, promotes NAD+ recycling, increases BNIP3 expression and mitophagy, and reduces EPC senescence. Our findings contribute to a better understanding of the connection between hypoxic culture conditions and the senescence of bone marrow-derived EPCs and provide a novel strategy to improve in vitro expansion of EPCs. [Display omitted] • Hypoxia is more advantageous to attenuate EPC senescence. • EPCs under normoxia and hypoxia present different LDH isozyme profiles. • Hypoxic LDH isozyme profile maintains efficient NAD + recycling. • Knock-down of LDHA and LDHB simultaneously impaired NAD+ recycling. • Knock-down of LDHA and LDHB simultaneously increased cell senescence under hypoxia. [ABSTRACT FROM AUTHOR]

المؤلفون: Yongqi Yue¹, Yanru Yue¹, Zeyu Fan¹, Yingying Meng¹, Chenglong Wen¹, Yalong An¹, Ying Yao¹, Xiao Li^1,2 nice.lixiao@gmail.com

المصدر: Journal of Biological Chemistry. Nov2023, Vol. 299 Issue 11, p1-10. 10p.

مصطلحات موضوعية: *LINCRNA, *LACTATE dehydrogenase, *GENE expression, *SUCCINATE dehydrogenase, *SUPEROXIDE dismutase, *OXIDANT status

مستخلص: Skeletal muscle consists of different muscle fiber types whose heterogeneity is characterized by different metabolic patterns and expression of MyHC isomers. The transformation of muscle fiber types is regulated by a complex molecular network in which long noncoding (lnc) RNAs play an important role. In this study, we found that lnc-H19 is more enriched in slow muscle fibers. In vitro, interference of lnc-H19 by siRNA significantly promoted the expression of fast muscle fiber gene MyHC IIB and inhibited the expression of the slow muscle fiber gene MyHC I, thereby leading to a fast muscle fiber phenotype. In addition, interference of lnc-H19 significantly inhibited mRNA expression of the mitochondrial genes, such as COX5A, COX-2, UQCRFSL, FABP3, and CD36. Overexpression of lnc-H19 resulted in an opposite result. In vivo, knockdown of lnc-H19 by AAV-shRNA-H19 suppressed the mRNA expression of the slow muscle fiber gene MyHC I and the protein expression of slow-MyHC. Simultaneously, mitochondria were reduced in number, swollen, and vacuolated. The activities of succinate dehydrogenase, lactic dehydrogenase, and superoxide dismutase were significantly inhibited, and malondialdehyde content was significantly increased, indicating that deficiency of lnc-H19 leads to decreased oxidative metabolism and antioxidant capacity in muscle. Furthermore, inhibition of lnc-H19 decreased the weight-bearing swimming time and limb suspension time of mice. In conclusion, our results revealed the role of lnc-H19 in maintaining slow muscle fiber types and maintaining exercise endurance, which may help to further improve the regulatory network of lnc-H19 in muscle function. [ABSTRACT FROM AUTHOR]

المؤلفون: Jiang, Ming^1,2 (AUTHOR) marvelousming@163.com, Qian, Hongyan^1,3 (AUTHOR) qhy672041647@163.com, Li, Qiqi^1,2 (AUTHOR) Liqiqi77321@163.com, Han, Yingying^1,4 (AUTHOR) hongyeyehong@yeah.net, Hu, Kesu¹ (AUTHOR) gc-sh@163.com

المصدر: Burns (03054179). Sep2023, Vol. 49 Issue 6, p1344-1355. 12p.

مصطلحات موضوعية: *ACUTE kidney failure, *LACTATE dehydrogenase, *BURN patients, *SURVIVAL rate, MORTALITY risk factors

مستخلص: Extensive burns are devastating trauma. This study aimed to explore the predictive value of early lactate dehydrogenase (LDH) level, the abbreviated burn severity index (ABSI) and their combination on acute kidney injury (AKI) and mortality after severe burns. 194 severe burn patients (TBSA ≥ 30%) were included. After multivariate analyses, early LDH value (first 24 h after admission) was an independent risk factor for early AKI (OR=1.095, CI,1.025–1.169,p = 0.007) and AKI (OR=1.452, CI,1.131–1.864, p = 0.003) in severe burn patients and was still a significant risk factor for mortality (OR=1.059, CI,1.006–1.115，p = 0.03). In ROC analysis, after combining LDH and ABSI, the AUC values were 0.925 for AKI, 0.926 for stage 3 AKI, and 0.904 for mortality. Based on cut-off values, patients were divided into different risk groups. The cumulative incidence of AKI (within 5 days, 30 days) and survival rate (within 60 days) were analyzed by the Kaplan-Meier method. The mortality, AKI incidence, and AKI staging showed a significant upward trend with the increasing risk level (P < 0.001). Early LDH level is an independent risk factor for early AKI and AKI. LDH combined with ABSI can better predict mortality and AKI than single indicators. • Early LDH level is an independent risk factor for AKI and a significant risk factor for mortality in severe burn patients. • LDH combined with ABSI score can better predict mortality and AKI from severe burns and more clearly stratify patient risk. • A clinical rationale enables the prompt implementation of early intervention. [ABSTRACT FROM AUTHOR]

المؤلفون: Akkus, E.¹ (AUTHOR), Turmus, U.² (AUTHOR), Utkan, G.¹ (AUTHOR)

المصدر: Annals of Oncology. 2024 Supplement 1, Vol. 35, pS46-S47. 2p.

مصطلحات موضوعية: *LACTATE dehydrogenase, *COLORECTAL cancer, *METASTASIS, *GENE expression, *TUMORS

المؤلفون: Minatovicz, Bruna¹ (AUTHOR), Sansare, Sameera¹ (AUTHOR), Mehta, Tanu¹ (AUTHOR), Bogner, Robin H.¹ (AUTHOR), Chaudhuri, Bodhisattwa^1,2 (AUTHOR) bodhi.chaudhuri@uconn.edu

المصدر: Journal of Pharmaceutical Sciences. Feb2023, Vol. 112 Issue 2, p482-491. 10p.

مصطلحات موضوعية: *LACTATE dehydrogenase, *SURFACE stability, *SURFACE area, *ICE, *PROTEIN stability

مستخلص: Although bulk biotherapeutics are often frozen during fill finish and shipping to improve their stability, they can undergo degradation leading to losses in biological activity during sub-optimal freeze-thaw (F/T) process. Except for a few small-scale studies, the relative contribution of various F/T stresses to the instability of proteins has not been addressed. Thus, the objective of this study was to determine the individual contributions of freeze-concentration, ice surface area, and processing time to protein destabilization at a practical manufacturing-scale. Lactate dehydrogenase (LDH) in histidine buffer solutions were frozen in 1L containers. The frozen solutions were sliced into representative samples and assessed for the ice specific surface area (SSA) and extent of solutes freeze-concentration. For the first time to our knowledge, ice SSA was measured in dried samples from large-volume protein solutions using volumetric nitrogen adsorption isotherms. SSA measurements of the freeze-dried cakes showed that the ice surface area increased with an increase in the freezing rate. The ice SSA was also impacted by the position of the sample within the container: samples closer to the active cooled surface of the container exhibited smaller ice surface area compared to ice-cored samples from the center of the bottle. The freeze-concentrate composition was determined by measuring LDH concentration in the ice-cored samples. The protein distributed more evenly throughout the frozen solution after fast freezing which also correlated with enhanced protein stability compared to slow freezing conditions. Overall, better protein stability parameters correlated with higher ice SSA and lower freeze-concentration extent which was achieved at a faster freezing rate. Thus, extended residence time of the protein at the freeze-concentrated microenvironment is the critical destabilizing factor during freezing of LDH in bulk histidine buffer system. This study expands the understanding of the relative contributions of freezing stresses which, coupled with the knowledge of cryoprotection mechanisms, is imperative to the development of optimized processes and formulations aiming stable frozen protein solutions. [Display omitted] [ABSTRACT FROM AUTHOR]

المؤلفون: Xiao, Meixing¹ (AUTHOR), Li, Anjie² (AUTHOR), Zhang, Xiaoyuan³ (AUTHOR), Ji, Bin^1,4 (AUTHOR) binji@wust.edu.cn

المصدر: Journal of Cleaner Production. Apr2024, Vol. 447, pN.PAG-N.PAG. 1p.

مصطلحات موضوعية: FUNCTIONAL groups, LACTATE dehydrogenase, WASTEWATER treatment, METABOLISM, PROTEIN structure

مستخلص: Although the hazards of zinc oxide particles (ZnO-NPs) in the field of wastewater treatment are receiving more and more attention, the responses of metabolism and migration pathways of microalgal-bacterial symbiosis to ZnO-NPs have not been well understood. Here, the distribution of ZnO-NPs along with its impact on metabolism in microalgal-bacterial granular sludge (MBGS) was studied. The results showed that over 95% of ZnO-NPs in the MBGS system were absorbed by sludge or enriched in the sludge layer in the form of zinc oxide, while releasing a small amount of Zn2+. The adsorption of ZnO-NPs by MBGS mainly relied on the –OH functional groups and protein structures. After ZnO-NPs adsorption, the cell membrane could be destroyed, resulting in the release of lactate dehydrogenase. At the genetic level, ZnO-NPs promoted gene abundance levels related to biological processes and enzyme glycosyl transferase synthesis, but inhibited intracellular biosynthesis and metabolism of genetic material, especially glutathione synthesis. Key functional and biosynthetic genes involved in metabolic processes were also inhibited, such as acs and glnA. This study explained in detail how ZnO-NPs altered and impacted on MBGS, which provided a reference for future practical applications of MBGS for wastewater treatment containing nanoparticles. [Display omitted] • ZnO-NPs were mainly enriched in sludge with slight Zn2+ release in solution. • ZnO-NPs may be adsorbed by the –OH functional groups and protein structures. • Cell membrane structure could be disrupted by ZnO-NPs. • Expression of key functional and biosynthetic genes could be inhibited by ZnO-NPs. • ZnO-NPs could inhibit the intracellular activity related to glycogen metabolism. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Cleaner Production is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

المؤلفون: Bonestroo, John^1,2,3 (AUTHOR) John.bonestroo@delaval.com, van der Voort, Mariska² (AUTHOR), Fall, Nils² (AUTHOR), Emanuelson, Ulf² (AUTHOR), Klaas, Ilka Christine¹ (AUTHOR), Hogeveen, Henk³ (AUTHOR)

المصدر: Journal of Dairy Science. Apr2022, Vol. 105 Issue 4, p3518-3529. 12p.

مصطلحات موضوعية: MILK yield, LACTATE dehydrogenase, ELECTRIC conductivity, SOMATIC cells, DAIRY cattle, MILKFAT, MILK

مستخلص: Reduction of milk yield is one of the principal components in the cost of mastitis. However, past research into the association between milk yield and mastitis indicators is limited. Past research has not been based on online or in-line daily measurements and has not fully explored nonlinearity and the thresholds at which milk yield starts to decrease. In dairy herds with automated milking systems equipped with sensors, mastitis indicators of individual cows are measured on an intraday frequency, which provides unprecedented avenues to explore such effects in detail. The aim of this observational study was primarily to investigate the nonlinear associations of lactate dehydrogenase (LDH), electrical conductivity (EC), and somatic cell count (SCC) with milk yield at various stages of lactation, parity, and mastitis chronicity status (i.e., whether the cow had SCC ≥200,000 SCC/mL for the last 28 d). We also investigated thresholds at which mastitis indicators (LDH, EC, and SCC) started to be negatively associated with milk yield. We used data from 21 automated milking system herds measuring EC and online SCC. Of these herds, 7 of the 21 additionally measured online LDH. We operationalized milk yield as milk synthesis rate in kilograms per hour. Applying a generalized additive model, we estimated the milk synthesis rate as a function of the 3 mastitis indicators for 3 different subgroups based on parity, stage of lactation, and mastitis chronicity. Partial dependence plots of the mastitis indicators were used to evaluate the milk synthesis rate to study if the milk synthesis rate was associated with mastitis indicators at a specific level. Results showed that milk synthesis rate decreased with increasing SCC, LDH, and EC, but in a nonlinear fashion. The thresholds at which milk synthesis rate started to decrease were 2.5 LnSCC (12,000 SCC/mL) to 3.75 LnSCC (43,000 SCC/mL), 0 to 1 LnLDH (1−2.7 U/L), and 5.0 to 6.0 mS/cm for EC. Additionally, another substantial decrease of milk synthesis rate was observed at thresholds of 5.625 LnSCC (277,000 SCC/mL) and 3 LnLDH (20 LDH U/L) but not for EC. Having chronic mastitis decreased milk synthesis rate in all models. The identified nonlinearities between mastitis indicators and milk synthesis rate should be incorporated in statistical models for more accurate estimations of milk loss due to mastitis. [ABSTRACT FROM AUTHOR]

: Copyright of Journal of Dairy Science is the property of Elsevier B.V. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)