Investigating the origin of high efficiency in confined multienzyme catalysis

Nanoscale ◽  
2019 ◽  
Vol 11 (45) ◽  
pp. 22108-22117 ◽  
Author(s):  
Yufei Cao ◽  
Xiaoyang Li ◽  
Jiarong Xiong ◽  
Licheng Wang ◽  
Li-Tang Yan ◽  
...  
Keyword(s):  
High Efficiency ◽  
Catalytic Efficiency ◽  
Enzyme Cascades

Biomimetic strategies have successfully been applied to confine multiple enzymes on scaffolds to obtain higher catalytic efficiency of enzyme cascades than freely distributed enzymes.

scholarly journals High Catalytic Efficiency of a Layered Coordination Polymer to Remove Simultaneous Sulfur and Nitrogen Compounds from Fuels

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 731
Author(s):  
Fátima Mirante ◽  
Ricardo F. Mendes ◽  
Filipe A. Almeida Paz ◽  
Salete S. Balula
Keyword(s):  
Coordination Polymer ◽  
High Efficiency ◽  
Catalytic Efficiency ◽  
Catalytic Performance ◽  
Nitrogen Compounds ◽  
One Pot ◽  
Extraction Solvent ◽  
Desulfurization Process ◽  
Morphological Differences ◽  
Model Diesel

An ionic lamellar coordination polymer based on a flexible triphosphonic acid linker, [Gd(H4nmp)(H2O)2]Cl2 H2O (1) (H6nmp stands for nitrilo(trimethylphosphonic) acid), presents high efficiency to remove sulfur and nitrogen pollutant compounds from model diesel. Its oxidative catalytic performance was investigated using single sulfur (1-BT, DBT, 4-MDBT and 4,6-DMDBT, 2350 ppm of S) and nitrogen (indole and quinolone, 400 ppm of N) model diesels and further, using multicomponent S/N model diesel. Different methodologies of preparation followed (microwave, one-pot, hydrothermal) originated small morphological differences that did not influenced the catalytic performance of catalyst. Complete desulfurization and denitrogenation were achieved after 2 h using single model diesels, an ionic liquid as extraction solvent ([BMIM]PF6) and H2O2 as oxidant. Simultaneous desulfurization and denitrogenation processes revealed that the nitrogen compounds are more easily removed from the diesel phase to the [BMIM]PF6 phase and consequently, faster oxidized than the sulfur compounds. The lamellar catalyst showed a high recycle capacity for desulfurization. The reusability of the diesel/H2O2/[BMIM]PF6 system catalyzed by lamellar catalyst was more efficient for denitrogenation than for desulfurization process using a multicomponent model diesel. This behavior is not associated with the catalyst performance but it is mainly due to the saturation of S/N compounds in the extraction phase.

scholarly journals Protease activity in single-chain prekallikrein

Blood ◽  
2020 ◽  
Vol 135 (8) ◽  
pp. 558-567 ◽  
Author(s):  
Ivan Ivanov ◽  
Ingrid M. Verhamme ◽  
Mao-fu Sun ◽  
Bassem Mohammed ◽  
Qiufang Cheng ◽  
...  
Keyword(s):  
Specific Activity ◽  
Catalytic Efficiency ◽  
Factor Xii ◽  
High Molecular Weight Kininogen ◽  
Contact Activation ◽  
Single Chain ◽  
Similar Activity ◽  
Artificial Surfaces ◽  
Protease Precursor ◽  
Enzyme Cascades

Abstract Prekallikrein (PK) is the precursor of the trypsin-like plasma protease kallikrein (PKa), which cleaves kininogens to release bradykinin and converts the protease precursor factor XII (FXII) to the enzyme FXIIa. PK and FXII undergo reciprocal conversion to their active forms (PKa and FXIIa) by a process that is accelerated by a variety of biological and artificial surfaces. The surface-mediated process is referred to as contact activation. Previously, we showed that FXII expresses a low level of proteolytic activity (independently of FXIIa) that may initiate reciprocal activation with PK. The current study was undertaken to determine whether PK expresses similar activity. Recombinant PK that cannot be converted to PKa was prepared by replacing Arg371 with alanine at the activation cleavage site (PK-R371A, or single-chain PK). Despite being constrained to the single-chain precursor form, PK-R371A cleaves high-molecular-weight kininogen (HK) to release bradykinin with a catalytic efficiency ∼1500-fold lower than that of kallikrein cleavage of HK. In the presence of a surface, PK-R371A converts FXII to FXIIa with a specific activity ∼4 orders of magnitude lower than for PKa cleavage of FXII. These results support the notion that activity intrinsic to PK and FXII can initiate reciprocal activation of FXII and PK in solution or on a surface. The findings are consistent with the hypothesis that the putative zymogens of many trypsin-like proteases are actually active proteases, explaining their capacity to undergo processes such as autoactivation and to initiate enzyme cascades.

scholarly journals Structural toggle in the RNaseH domain of Prp8 helps balance splicing fidelity and catalytic efficiency

2017 ◽  
Vol 114 (18) ◽  
pp. 4739-4744 ◽  
Author(s):  
Megan Mayerle ◽  
Madhura Raghavan ◽  
Sarah Ledoux ◽  
Argenta Price ◽  
Nicholas Stepankiw ◽  
...  
Keyword(s):  
High Efficiency ◽  
Catalytic Efficiency ◽  
Mrna Splicing ◽  
Catalytic Core ◽  
Eukaryotic Gene ◽  
Functional Classes ◽  
Reporter Assays

Pre-mRNA splicing is an essential step of eukaryotic gene expression that requires both high efficiency and high fidelity. Prp8 has long been considered the “master regulator” of the spliceosome, the molecular machine that executes pre-mRNA splicing. Cross-linking and structural studies place the RNaseH domain (RH) of Prp8 near the spliceosome’s catalytic core and demonstrate that prp8 alleles that map to a 17-aa extension in RH stabilize it in one of two mutually exclusive structures, the biological relevance of which are unknown. We performed an extensive characterization of prp8 alleles that map to this extension and, using in vitro and in vivo reporter assays, show they fall into two functional classes associated with the two structures: those that promote error-prone/efficient splicing and those that promote hyperaccurate/inefficient splicing. Identification of global locations of endogenous splice-site activation by lariat sequencing confirms the fidelity effects seen in our reporter assays. Furthermore, we show that error-prone/efficient RH alleles suppress a prp2 mutant deficient at promoting the first catalytic step of splicing, whereas hyperaccurate/inefficient RH alleles exhibit synthetic sickness. Together our data indicate that prp8 RH alleles link splicing fidelity with catalytic efficiency by biasing the relative stabilities of distinct spliceosome conformations. We hypothesize that the spliceosome “toggles” between such error-prone/efficient and hyperaccurate/inefficient conformations during the splicing cycle to regulate splicing fidelity.

scholarly journals Dye Decoloring Peroxidase Structure, Catalytic Properties and Applications: Current Advancement and Futurity

Catalysts ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 955
Author(s):  
Lingxia Xu ◽  
Jianzhong Sun ◽  
Majjid A. Qaria ◽  
Lu Gao ◽  
Daochen Zhu
Keyword(s):  
Protein Structure ◽  
Amino Acid ◽  
High Efficiency ◽  
Chemical Properties ◽  
Catalytic Efficiency ◽  
Industrial Applications ◽  
Research Strategy ◽  
Amino Acid Sequences ◽  
Alkali Resistance ◽  
Wide Range

Dye decoloring peroxidases (DyPs) were named after their high efficiency to decolorize and degrade a wide range of dyes. DyPs are a type of heme peroxidase and are quite different from known heme peroxidases in terms of amino acid sequences, protein structure, catalytic residues, and physical and chemical properties. DyPs oxidize polycyclic dyes and phenolic compounds. Thus they find high application potentials in dealing with environmental problems. The structure and catalytic characteristics of DyPs of different families from the amino acid sequence, protein structure, and enzymatic properties, and analyzes the high-efficiency degradation ability of some DyPs in dye and lignin degradation, which vary greatly among DyPs classes. In addition, application prospects of DyPs in biomedicine and other fields are also discussed briefly. At the same time, the research strategy based on genetic engineering and synthetic biology in improving the stability and catalytic activity of DyPs are summarized along with the important industrial applications of DyPs and associated challenges. Moreover, according to the current research findings, bringing DyPs to the industrial level may require improving the catalytic efficiency of DyP, increasing production, and enhancing alkali resistance and toxicity.

scholarly journals Smart paper transformer: new insight for enhanced catalytic efficiency and reusability of noble metal nanocatalysts

2020 ◽  
Vol 11 (11) ◽  
pp. 2915-2925 ◽  
Author(s):  
Qijie Jin ◽  
Lei Ma ◽  
Wan Zhou ◽  
Yuesong Shen ◽  
Olivia Fernandez-Delgado ◽  
...  
Keyword(s):  
Noble Metal ◽  
High Efficiency ◽  
Catalytic Efficiency ◽  
Phase Conversion ◽  
Paper And Pulp

A smart paper transformer supported nanocatalyst platform is developed based on the facile phase conversion between paper and pulp for both high-efficiency and high-reusability catalysis, with wide applications demonstrated by using Au nanosponge.

scholarly journals The Application of Biomass-Based Catalytic Materials in the Synthesis of Cyclic Carbonates from CO2 and Epoxides

Molecules ◽  
2020 ◽  
Vol 25 (16) ◽  
pp. 3627 ◽  
Author(s):  
Li Guo ◽  
Ran Zhang ◽  
Yuge Xiong ◽  
Dandan Chang ◽  
Haoran Zhao ◽  
...  
Keyword(s):  
High Efficiency ◽  
Low Cost ◽  
Coupling Reaction ◽  
Catalytic Efficiency ◽  
Renewable Resource ◽  
Co2 Conversion ◽  
Cyclic Carbonates ◽  
Reaction Conditions ◽  
Co Catalysts ◽  
Carbon Dioxide Co2

The synthesis of cyclic carbonates from carbon dioxide (CO2) and epoxides is a 100% atom economical reaction and an attractive pathway for CO2 utilisation. Because CO2 is a thermodynamically stable molecule, the use of catalysts is mandatory in reducing the activation energy of the CO2 conversion. Considering environmental compatibility and the high-efficiency catalytic conversion of CO2, there is the strong need to develop green catalysts. Biomass-based catalysts, a type of renewable resource, have attracted considerable attention due to their unique properties—non-toxic, low-cost, pollution-free, etc. In this review, recent advances in the development of biomass-based catalysts for the synthesis of cyclic carbonates by CO2 and epoxides coupling are summarized and discussed in detail. The effect of biomass-based catalysts, functional groups, reaction conditions, and co-catalysts on the catalytic efficiency and selectivity of synthesizing cyclic carbonates process is discussed. We intend to provide a comprehensive understanding of recent experimental and theoretical progress of CO2 and epoxides coupling reaction and pave the way for both CO2 conversion and biomass unitization.

Silver(i) NHC mediated C–C bond activation of alkyl nitriles and catalytic efficiency in oxazoline synthesis

2015 ◽  
Vol 51 (41) ◽  
pp. 8699-8701 ◽  
Author(s):  
Rachael Heath ◽  
Helge Müller-Bunz ◽  
Martin Albrecht
Keyword(s):  
High Efficiency ◽  
Bond Activation ◽  
Aldol Condensation ◽  
Bond Cleavage ◽  
Catalytic Efficiency ◽  
Carbene Complexes ◽  
Ambient Temperatures ◽  
Mild Conditions ◽  
New Applications

C–C bond cleavage is achieved with silver carbene species under relatively mild conditions (80 °C) stoichiometrically, and aldol condensation is catalyzed at ambient temperatures in high efficiency, with turnover numbers up to 5000 h−1, thus disclosing new applications and synthetic opportunities based on easily accessible silver carbene complexes.

scholarly journals Accelerating charge transfer via nonconjugated polyelectrolyte interlayers toward efficient versatile photoredox catalysis

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Tao Li ◽  
Chuang Feng ◽  
Boon Kar Yap ◽  
Xuhui Zhu ◽  
Biquan Xiong ◽  
...  
Keyword(s):  
Charge Transfer ◽  
High Efficiency ◽  
Catalytic Efficiency ◽  
Hole Transport ◽  
Photoredox Catalysis ◽  
Transport Efficiency ◽  
Transfer Capability ◽  
Allylamine Hydrochloride ◽  
Low Charge ◽  
Kinetics Of

AbstractOne of the challenges for high-efficiency single-component-based photoredox catalysts is the low charge transfer and extraction due to the high recombination rate. Here, we demonstrate a strategy to precisely control the charge separation and transport efficiency of the catalytic host by introducing electron or hole extraction interlayers to improve the catalytic efficiency. We use simple and easily available non-conjugated polyelectrolytes (NCPs) (i.e., polyethyleneimine, PEI; poly(allylamine hydrochloride), PAH) to form interlayers, wherein such NCPs consist of the nonconjugated backbone with charge transporting functional groups. Taking CdS as examples, it is shown that although PEI and PAH are insulators and therefore do not have the ability to conduct electricity, they can form good electron or hole transport extraction layers due to the higher charge-transfer kinetics of pendant groups along the backbones, thereby greatly improving the charge transfer capability of CdS. Consequently, the resultant PEI-/PAH-functionalized nanocomposites exhibit significantly enhanced and versatile photoredox catalysis.

Tuning the Edge-Site Activity of 2H Phase MoSe2 for Hydrogen Evolution Reaction via Sulfur Substitution and Strain Engineering

2020 ◽  
Vol 12 (10) ◽  
pp. 1446-1456
Author(s):  
Ziwei Xu ◽  
Guanghui Zhao ◽  
Mingyuan Wang ◽  
Jingjing Liang ◽  
Shahid Hussain ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Hydrogen Evolution ◽  
Hydrogen Evolution Reaction ◽  
Density Functional ◽  
High Efficiency ◽  
Low Cost ◽  
Catalytic Efficiency ◽  
Strain Engineering ◽  
Catalyst Design ◽  
Potential Candidate

The 2H phase MoSe2 of high chemical stability and excellent catalytic activity is a promising catalyst for the hydrogen evolution reaction (HER) as a potential candidate, due to its low cost, high efficiency and abundant production. However, the HER catalytic efficiency of MoSe2 largely depends on the activity of reaction sites including the basal plane and the edges, and remains low because only the Mo edge sites are active. Herein, we have calculated the structural stability, catalytic activity, and strain engineering on sulfur substituted MoSe2 catalytic structures (Mo(Se1–xSx)2) by density functional theory. The results demonstrate that most of Mo(Se1–xSx)2 monolayers are thermodynamically stable and the HER activity of the Mo(Se1–xSx)2 monolayers can be effectively tuned by both element substitution and strain engineering with the mechanisms uncovered at the atomic level. This study provides the experiments theoretical references for the novel catalyst design of the hydrogen evolution reaction.

scholarly journals A Genome-Centric Approach Reveals a Novel Glycosyltransferase from the GA A07 Strain of Bacillus thuringiensis Responsible for Catalyzing 15-O-Glycosylation of Ganoderic Acid A

2019 ◽  
Vol 20 (20) ◽  
pp. 5192 ◽  
Author(s):  
Te-Sheng Chang ◽  
Tzi-Yuan Wang ◽  
Tzu-Yu Hsueh ◽  
Yu-Wen Lee ◽  
Hsin-Mei Chuang ◽  
...  
Keyword(s):  
Bacillus Thuringiensis ◽  
Complete Genome ◽  
High Efficiency ◽  
Catalytic Efficiency ◽  
Soluble Form ◽  
Phylogenomic Analysis ◽  
Ganoderic Acid ◽  
A Genome ◽  
Liquid Chromatographic Analysis ◽  
Liquid Chromatographic

Strain GA A07 was identified as an intestinal Bacillus bacterium of zebrafish, which has high efficiency to biotransform the triterpenoid, ganoderic acid A (GAA), into GAA-15-O-β-glucoside. To date, only two known enzymes (BsUGT398 and BsUGT489) of Bacillus subtilis ATCC 6633 strain can biotransform GAA. It is thus worthwhile to identify the responsible genes of strain GA A07 by whole genome sequencing. A complete genome of strain GA A07 was successfully assembled. A phylogenomic analysis revealed the species of the GA A07 strain to be Bacillus thuringiensis. Forty glycosyltransferase (GT) family genes were identified from the complete genome, among which three genes (FQZ25_16345, FQZ25_19840, and FQZ25_19010) were closely related to BsUGT398 and BsUGT489. Two of the three candidate genes, FQZ25_16345 and FQZ25_19010, were successfully cloned and expressed in a soluble form in Escherichia coli, and the corresponding proteins, BtGT_16345 and BtGT_19010, were purified for a biotransformation activity assay. An ultra-performance liquid chromatographic analysis further confirmed that only the purified BtGT_16345 had the key biotransformation activity of catalyzing GAA into GAA-15-O-β-glucoside. The suitable conditions for this enzyme activity were pH 7.5, 10 mM of magnesium ions, and 30 °C. In addition, BtGT_16345 showed glycosylation activity toward seven flavonoids (apigenein, quercetein, naringenein, resveratrol, genistein, daidzein, and 8-hydroxydaidzein) and two triterpenoids (GAA and antcin K). A kinetic study showed that the catalytic efficiency (kcat/KM) of BtGT_16345 was not significantly different compared with either BsUGT398 or BsUGT489. In short, this study identified BtGT_16345 from B. thuringiensis GA A07 is the catalytic enzyme responsible for the 15-O-glycosylation of GAA and it was also regioselective toward triterpenoid substrates.

Sign in / Sign up

Export Citation Format

Share Document