BIOPROCESS AND BIOSYSTEMS ENGINEERING
·
2016
·Vol. 39
·期 4
·603-611
·
IF 1.901
Zhang Jian-Dong,Cui Zhi-Mei,Fan Xiao-Jun,Wu Hua-Lei,Chang Hong-Hong
Two uncharacterized nicotinamide adenine dinucleotide (NADH) oxidases (named as LpNox1, LpNox2) from Lactobacillus pentosus ATCC 8041 were cloned and overexpressed in Escherichia coli BL21 (DE3). The sequence analysis revealed that the two enzymes are water-forming Noxs with 64 % and 52 % identity to LbNox from Lactobacillus brevis DSM 20054. The optimal pH and temperature of the purified LpNox1 and LpNox2 were 7.0 and 8.0 and 35 and 40 °C, respectively, with K
M of 99.0 μM (LpNox1) and 27.6 μM (LpNox2), and yielding catalytic efficiency k
cat / K
M of 1.0 and 0.2 μM −1 s −1 , respectively. Heat inactivation studies revealed that the two enzymes are relatively instable. The application of LpNox1 for the regeneration of NAD + was demonstrated by coupling with a glycerol dehydrogenase-catalyzed oxidation of glycerol to 1,3-dihydroxyacetone. The characteristics of the LpNox1 could prove to be of interest in industrial application such as NAD + regeneration in dehydrogenase-catalyzed oxidations.
研究领域:
生物化学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED BIOCHEMISTRY AND BIOTECHNOLOGY
·
2025
·
IF 3.3
He Ying,Huang Ao,Liu Yun
Phospholipase D (PLD) is a valuable enzyme in industrial processes for converting phosphatidylcholine (PC) to phosphatidylserine (PS). In this study, a strain of Bacillus cereus was isolated from soil and identified through 16S rRNA sequencing. To enhance PLD activity, various mutagenesis strategies—including chemical treatment, irradiation, and their combinations—were employed, resulting in four high-activity positive mutants (C-7, I-12, CI 7–12, and IC 13–14). Among these, the CI 7–12 mutant exhibited a significantly higher enzymatic activity, showing a 3.12-fold increase (312.2%) compared to the wild-type strain. Fermentation conditions were optimied using response surface methodology (RSM), achieving a PLD activity of 35 U/mL. The enzyme demonstrated stability over a wide temperature range (30–60 °C) and pH range (6–10), with a half-life of 128 days. Kinetic analysis revealed a V max of 20.04 μmol/h and a K m of 7.13 μmol/mL, indicating efficient activity. In bioconversion experiments, the PLD-enriched fermentation broth catalyzed the conversion of PC to PS, achieving a 53.0% conversion rate and a 92.3% selectivity for PS in a two-phase system. These findings expand the potential sources of PLD and underscore its applicability for PS production in biotechnological applications.
研究领域:
微生物学
·
生物化学
·
工业生物技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanoscale
·
2017
·Vol. 9
·期 32
·11806-11813
·
IF 7.367
T. M. Chen,X. J. Wu,J. X. Wang,G. W. Yang
As one of the transition metal dichalcogenide materials, WSe2 in the form of a few layers (nanosheets) have received much attention due to their unique physical, optical and electrical properties. Herein, we demonstrate that WSe2 nanosheets possess intrinsic enzyme mimic activity. Under acidic conditions, they exhibit pronounced peroxidase-like property. The Michaelis–Menten kinetics indicate that the catalytic activity of WSe2 nanosheets is comparable to that of horseradish peroxidase. Based on the color reaction, a platform of WSe2 nanosheets was constructed to detect glucose concentration and it showed high sensitivity and high selectivity, which means that WSe2 nanosheets with peroxidase-like property can be used to develop a highly sensitive and selective colorimetric method for glucose detection. Moreover, due to the electron-transferring and antioxidant properties of WSe2 few layers, the peroxidase-like catalysis is proposed. These findings pave the way for further application of WSe2 nanosheets in nano-biomedicine.
研究领域:
纳米医学
·
生物化学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
FOOD CHEMISTRY
·
2017
·
IF 4.529
Biying Wang,Yajun Bai,Taiping Fan,Xiaohui Zheng,Yujie Cai
Alpha-keto acid decarboxylases can convert keto acids to their corresponding aldehydes, which are often volatile aroma compounds. The gene encoding α-keto acid decarboxylase in Proteus mirabilis JN458 was cloned, and the enzyme overexpressed in Escherichia coli BL21 (DE3), purified in high yield, and characterised. The molecular weight is 62.291 kDa by MALDI-TOF MS, and optimum activity at pH 6.0 and 40–50 °C. The enzyme is a typical decarboxylase, dependent on thiamine diphosphate and Mg 2+ as cofactors. For the decarboxylation reaction, the enzyme displayed a broad substrate range. Kinetic parameters were determined using 4-methyl-2-oxopentanoic acid, phenyl pyruvate and 3-methyl-2-oxopentanoic acid as substrates. K m and k cat values for phenyl pyruvate were 0.62 mM and 77.38 s −1 , respectively, and the k cat / K m value was 124.81 mM −1 s −1 . The enzyme properties suggest it may act effectively under cheese ripening conditions.
研究领域:
生物化学
·
食品科学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
ARCHIVES OF BIOCHEMISTRY AND BIOPHYSICS
·
2014
·
IF 3.043
Chenxi Ning,Erzheng Su,Dongzhi Wei
Lodderomyces elongisporus LH703 isolated from soil samples contained three novel aldo–keto reductases (AKRs) (LEAKR 48, LEAKR 49, and LEAKR 50). The three enzymes were cloned, expressed, and purified to homogeneity for characterization. These three AKRs shared <40% amino acid identity with each other. LEAKR 50 was identified as a member of AKR3 family, whereas the other two LEAKRs were identified as members of two novel AKR families, respectively. All the three AKRs required nicotinamide adenine dinucleotide phosphate as a cofactor. However, they showed diverse characteristics, including optimum catalyzing conditions, resistance to adverse reaction conditions, and substrate specificity. LEAKR 50 was estimated to be a promising biocatalyst that could reduce ethyl 4-chloroacetoacetate with high enantiomeric excess (98% e. e.) and high activity residue under adverse conditions.
研究领域:
生物化学
·
酶学
·
微生物学
✓ 已验证
DOI
PubMed
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2015
·Vol. 96
·期 8
·2925-2931
·
IF 1.714
Rui Cai,Dongyu Li,Yahong Yuan,Zhouli Wang,Chunfeng Guo,Bin Liu,Tianli Yue
BACKGROUND Vanillic acid decarboxylase (VAD) is the key enzyme responsible for guaiacol production in Alicyclobacillus acidoterrestris ; however, information related to this enzyme is currently unavailable. The aim of this study is to characterise the VAD from A. acidoterrestris . RESULTS Specific activity of VAD in vanillic acid-induced A. acidoterrestris DSM 3923 cells was highest in the early stage of the log phase, and almost undetectable in the stationary and death phases. Of the four techniques used to extract VAD, sonication was found to be the most effective and recovered 3.23 U mg −1 of VAD. Through optimisation of the crucial parameters for sonication, the recovery of VAD had more than doubled (6.81 U mg −1 ). The crude enzyme extract was purified by ammonium sulfate precipitation and a 9.87-fold purification was obtained. The partially purified VAD exhibited optimum activity at pH 6.0–6.5, 45°C and was stable at pH 5.0–7.5, 20–45°C. The K m and V max values of the VAD were 0.53 mmol L −1 and 96 U mg −1 protein, respectively. VAD activity was stimulated by Co 2+ and Mn 2+ , but was inhibited by Ni 2+ , Cu 2+ , Ba 2+ and Fe 3+ . Cinnamic acid, ferulic acid, resveratrol, quercetin and rutin at the concentration of 1 mmol L −1 could completely inhibit the activity of VAD. CONCLUSION The present study provides the first report on the characteristics of the VAD from A. acidoterrestris , which will contribute to the development of more effective control methods to minimise A. acidoterrestris -related spoilage in fruit juices. © 2015 Society of Chemical Industry
研究领域:
微生物学
·
酶学
·
食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2019
·
IF 6.393
Xiaolun Peng,Jiaxin Zheng,Ting Bao,Wei Wen,Xiuhua Zhang,Shengfu Wang
A novel dual-amplified electrochemical biosensor based on Exonuclease III (Exo III) and Cu(II)-dependent DNAzymes (Cu 2+ -DNAzymes) was developed for ultrasensitive electrochemical evaluation of pyrophosphatase (PPase) activity with the help of one-step synthesis of BSA-directed gold nanoclusters-manganese dioxide (AuNCs-MnO 2 ) nanoflakes with peroxidase-like characteristics as a catalytic platform. For biosensor preparation, under the catalytic hydrolysis of the PPase, copper ion (Cu 2+ ) was released from the Cu 2+ -coordinated pyrophosphate ions (Cu 2+ –PPi) complex which was formed by the coordination reaction of copper ion (Cu 2+ ) and pyrophosphate ions (PPi). The released Cu 2+ , acting as an indispensable cofactor, could activate Cu 2+ -DNAzymes to turn on the amplification process and then generated the single-stranded product (S1) that hybridized to the hairpin-type capture probe (HP1). Subsequently, the addition of Exonuclease III (Exo III) enabled the reuse of S1 and produced the final cleavage fragment, which closely linked the functionalized AuNCs-MnO 2 nanoflakes to the electrode surface. The superior peroxidase-like characteristics of nanoflakes provided stable catalytic signal output and realized electrochemical monitoring of PPase activity with a detection limit of 0.0058 mU/mL. Importantly, the biosensor also had a good performance in inhibitors screening of target PPase. The use of AuNCs-MnO 2 nanoflakes instead of natural enzymes combined with DNAzymes amplification strategy offered more possibilities for the detection of various biomolecules.
研究领域:
生物化学
·
纳米技术
·
分析化学
·
生物医学工程
✓ 已验证
DOI
高影响因子
Acta Biomaterialia
·
2023
·
IF 9.7
Xu Jin,Jie Shan,Jiemin Zhao,Tao Wang,Wei Zhang,Shijie Yang,Haisheng Qian,Liang Cheng,Xu-Lin Chen,Xianwen Wang
Infections and oxidative stress complicate wound healing. In recent years, nanomaterials with natural enzymatic activities have enabled the development of new antibacterial pathways. In this study, Cu-Fe 3 O 4 nanoclusters with multienzyme properties were synthesised. Interestingly, they exhibited activity similar to that of horseradish peroxidase (POD) in acidic environments but their functions resembled superoxide dismutase and catalase in neutral or weakly alkaline environments. In vitro studies have demonstrated the good free-radical scavenging activity of Cu-Fe 3 O 4 nanoclusters in a neutral environment. Under acidic conditions, Cu-Fe 3 O 4 nanoclusters combined with H 2 O 2 demonstrated good antibacterial activity against methicillin-resistant Staphylococcus aureus ( MRSA ) and Escherichia coli ( E. coli ). The combination of Cu-Fe 3 O 4 and H 2 O 2 was found to be effective in preventing MRSA infections and promoting wound healing in animal models. RNA sequencing (RNA-seq) technology revealed that chemodynamic therapy (CDT) using nanoparticles can interfere with metabolic processes such as galactose metabolism in MRSA bacteria, destroy the transport system on the surface of MRSA , and affect quorum sensing to hinder the formation of biofilms, thus achieving effective antibacterial efficacy. The use of Cu-Fe 3 O 4 nanoclusters as a novel class of multi-catalytically active nanozymes in the anti-infection of disease-causing pathogens and wound healing has significant potential. Statement of Significance Cu-Fe 3 O 4 nanoclusters with multienzyme properties were successfully prepared by a solvothermal method. Cu-Fe 3 O 4 nanoclusters exhibited horseradish peroxidase (POD)-like activity in acidic environments and also showed synergistic effects similar to superoxide dismutase peroxidase in neutral or weakly basic environments. More importantly, these Cu-Fe 3 O 4 nanoclusters showed high biosafety with no apparent in vivo toxicity. Chemodynamic therapy (CDT) using Cu-Fe 3 O 4 nanoclusters was revealed by RNA sequencing (RNA-Seq) technology to interfere with the metabolic processes of MRSA bacteria, such as galactose metabolism, disrupt the MRSA surface transport system, and impede biofilm formation, resulting in effective antibacterial efficacy. The use of Cu-Fe 3 O 4 nanoclusters for anti-infection and wound healing of pathogenic pathogens has significant potential as a novel class of multi-catalytic active nanoclusters.
研究领域:
纳米技术
·
生物医学工程
·
伤口愈合
·
抗菌治疗
·
酶模拟
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）