443892-10-2Relevant articles and documents
N, O -Chelating quinoline-based half-sandwich organorhodium and -iridium complexes: Synthesis, antiplasmodial activity and preliminary evaluation as transfer hydrogenation catalysts for the reduction of NAD+
Stringer, Tameryn,Melis, Diana R.,Smith, Gregory S.
, p. 13143 - 13148 (2019)
Two Rh(iii) and Ir(iii) half-sandwich quinoline-based complexes were synthesised and evaluated for their in vitro antiplasmodial activity against the chloroquine-sensitive NF54 and multi-drug resistant K1 strains of the human malaria parasite, Plasmodium falciparum. These half-sandwich organometallic complexes can also facilitate transfer hydrogenation, by converting β-nicotinamide adenine dinucleotide (NAD+) to its reduced form (NADH) in the presence of sodium formate. Co-administration of the iridium(iii) complex with sodium formate enhances the antiplasmodial activity in the chloroquine-resistant (K1) strain of Plasmodium falciparum, intimating that metal-mediated transfer hydrogenations can be achieved in malarial parasitic cells.
Implantable Biosupercapacitor Inspired by the Cellular Redox System
Jang, Yongwoo,Park, Taegyu,Kim, Eunyoung,Park, Jong Woo,Lee, Dong Yeop,Kim, Seon Jeong
, p. 10563 - 10567 (2021)
The carbon nanotube (CNT) yarn supercapacitor has high potential for in vivo energy storage because it can be used in aqueous environments and stitched to inner parts of the body, such as blood vessels. The biocompatibility issue for frequently used pseudocapacitive materials, such as metal oxides, is controversial in the human body. Here, we report an implantable CNT yarn supercapacitor inspired by the cellular redox system. In all living cells, nicotinamide adenine dinucleotide (NAD) is a key redox biomolecule responsible for cellular energy transduction to produce adenosine triphosphate (ATP). Based on this redox system, CNT yarn electrodes were fabricated by inserting a twist in CNT sheets with electrochemically deposited NAD and benzoquinone for redox shuttling. Consequently, the NAD/BQ/CNT yarn electrodes exhibited the maximum area capacitance (55.73 mF cm?2) under physiological conditions, such as phosphate-buffered saline and serum. In addition, the yarn electrodes showed a negligible loss of capacitance after 10 000 repeated charge/discharge cycles and deformation tests (bending/knotting). More importantly, NAD/BQ/CNT yarn electrodes implanted into the abdominal cavity of a rat's skin exhibited the stable in vivo electrical performance of a supercapacitor. Therefore, these findings demonstrate a redox biomolecule-applied platform for implantable energy storage devices.
Significance of the 20-kDa subunit of heterodimeric 2-deoxy-scyllo-inosose synthase for the biosynthesis of butirosin antibiotics in Bacillus circulans
Tamegai, Hideyuki,Nango, Eriko,Koike-Takeshita, Ayumi,Kudo, Fumitaka,Kakinuma, Katsumi
, p. 1538 - 1545 (2002)
A gene (btrC2) encoding the 20-kDa subunit of 2-deoxy-scyllo-inosose (DOI) synthase, a key enzyme in the biosynthesis of 2-deoxystreptamine, was identified from the butirosin-producer Bacillus circulans by reverse genetics. The deduced amino acid sequence of BtrC2 closely resembled that of YaaE of B. subtilis, but the function of the latter has not been known to date. Instead, BtrC2 appeared to show sequence similarity to a certain extent with HisH of B. subtilis, an amidotransferase subunit of imidazole glycerol phosphate synthase. Disruption of btrC2 reduced the growth rate compared with the wild type, and simultaneously antibiotic producing activity was lost. Addition of NH4Cl to the medium complemented only the growth rate of the disruptant, and both the growth rate and antibiotic production were restored by addition of yeast extract. In addition, a heterologous co-expression system of btrC2 with btrC was constructed in Escherichia coli. The simultaneously over-expressed BtrC2 and BtrC constituted a heterodimer, the biochemical features of which resembled those of DOI synthase from B. circulans more than those of the recombinant homodimeric BtrC. Despite the similarity of BtrC2 to HisH the heterodimer showed neither aminotransfer nor amidotransfer activity for 2-deoxy-scyllo-inosose as a substrate. All the observations suggest that BtrC2 is involved not only in the secondary metabolism, but also in the primary metabolism in B. circulans. The function of BtrC2 in the butirosin biosynthesis appears to be indirect, and may be involved in stabilization of DOI synthase and in regulation of its enzyme activity.
Mathematical treatment of electrophoretically mediated microanalysis.
Harmon,Patterson,Regnier
, p. 2655 - 2662 (1993)
A new concept in reaction-based chemical analysis is introduced and theoretically described. By utilization of the variability in electrophoretic mobilities among charged species, spatially distinct zones of chemical reagents can be electrophoretically merged under the influence of an applied electric field. Electrophoretically mediated microanalysis (EMMA) exploits this phenomenon as a basis for chemical analysis utilizing capillary electrophoretic systems. EMMA is described in terms of the four stages required for reaction-based analysis: (1) analyte and analytical reagent metering; (2) initiation of reaction; (3) control of reaction conditions and product formation; (4) detection of species whose production or depletion is indicative of the concentration or quantity of the analyte of interest. The method is illustrated by the enzymatic oxidation of ethanol to acetaldehyde by alcohol dehydrogenase with the concurrent reduction of NAD+ to NADH monitored at 340 nm. Experimental results for both substrate and enzyme determinations are shown to agree with the presented theory.
Synthesis of 4-alkylpyrazoles as inhibitors of liver alcohol dehydrogenase
Echevarria,Martin,Perez,Rozas
, p. 303 - 305 (1994)
Theoretical studies by shape analysis of the molecular electrostatic potential on the van der Waals surfaces of a set of 4-alkylpyrazoles predicted 4-isopentyl derivative as a good inhibitor of liver alcohol dehydrogenase. Thus, the new 4-isopentyl and the already known 4-octylpyrazole have been prepared by a novel route. The isopentyl derivative has been tested as inhibitor of horse liver alcohol dehydrogenase giving the result predicted by the theoretical studies.
Emissive Synthetic Cofactors: Enzymatic Interconversions of tzA Analogues of ATP, NAD+, NADH, NADP+, and NADPH
Hallé, Fran?ois,Fin, Andrea,Rovira, Alexander R.,Tor, Yitzhak
, p. 1087 - 1090 (2018)
A series of enzymatic transformations, which generate visibly emissive isofunctional cofactors based on an isothiazolo[4,3-d]pyrimidine analogue of adenosine (tzA), was developed. Nicotinamide adenylyl transferase condenses nicotinamide mononucleotide and tzATP to yield NtzAD+, which can be enzymatically phosphorylated by NAD+ kinase and ATP or tzATP to the corresponding NtzADP+. The latter can be engaged in NADP-specific coupled enzymatic transformations involving conversion to NtzADPH by glucose-6-phosphate dehydrogenase and reoxidation to NtzADP+ by glutathione reductase. The NtzADP+/NtzADPH cycle can be monitored in real time by fluorescence spectroscopy.
NAD+-dependent (S)-specific secondary alcohol dehydrogenase involved in stereoinversion of 3-pentyn-2-ol catalyzed by Nocardia fusca AKU 2123
Xie, Sheng-Xue,Ogawa, Jun,Shimizu, Sakayu
, p. 1721 - 1729 (1999)
An NAD+-dependent alcohol dehydrogenase was purified to homogeneity from Nocardia fusca AKU 2123. The enzyme catalyzed (S)-specific oxidation of 3-pentyn-2-ol (PYOH), i.e., part of the stereoinversion reaction for the production of (R)-PYOH, which is a valuable chiral building block for pharmaceuticals, from the racemate. The enzyme used a broad variety of secondary alcohols including alkyl alcohols, alkenyl alcohols, acetylenic alcohols, and aromatic alcohols as substrates. The oxidation was (S)-isomer specific in every case. The Km and Vmax for (S)-PYOH and (S)-2-hexanol oxidation were 1.6 mM and 53 μmol/min/mg, and 0.33 mM and 130/μmol/min/mg, respectively. The enzyme also catalyzed stereoselective reduction of carbonyl compounds. (S)-2-Hexanol and ethyl (R)-4-chloro-3-hydroxybutanoate in high optical purity were produced from 2-hexanone and ethyl 4-chloro-3-oxobutanoate by the purified enzyme, respectively. The Km and Vmax for 2-hexanone reduction were 2.5 mM and 260 μmol/min/mg. The enzyme has a relative molecular mass of 150,000 and consists of four identical subunits. The NH2-terminal amino acid sequence of the enzyme shows similarity with those of the carbonyl reductase from Rhodococcus erythropolis and phenylacetaldehyde reductase from Corynebacterium sp.
The Characteristics and Applications of Recombinant Cholesterol Dehydrogenase
Kishi, Koji,Watazu, Yoshifumi,Katayama, Yoshiaki,Okabe, Hiroaki
, p. 1352 - 1358 (2000)
Mass production of an r-CDH derived from Nocardia species was made possible by gene technology. (Horinouchi et al., Applied and Environmental Microbiology, 57, 1386-1393 (1991)). However, the characteristics of the r-CDH have not been studied in detail and have not been improved enough for industrial use. We accordingly characterized both the native-CDH and the r-CDH prepared from Streptomyces lividans. Both CDHs were monomers with molecular masses of 37 kDa. The Km of r-CDH was 2.50×10-3M for cholesterol and 2.33 × 10-4M for NAD. The activators of CDHs were TritonX-100 and cholate. TritonX-405, Ag+, and Zn2+ inhibited both enzymes. The residual activity of native CDH after heat treatment was 32% (37°C, 60 min), while the r-CDH showed a residual activity of 87% (37°C, 60 min). The r-CDH is an enzyme with high substrate specificity for cholesterol as well as native CDH and higher thermal stability than native CDH. We have developed a novel serum cholesterol assay using the r-CDH, which permits the direct measurement of cholesterol by measuring NADH reaction products. We conclude that this r-CDH enzyme is useful and can be used to measure cholesterol in a clinical chemistry setting.
Coenzyme analogs: Excellent substitutes (not poor imitations) for electrochemical regeneration
Lee, Hye Jung,Lee, Sahng Ha,Park, Chan Beum,Won, Keehoon
, p. 12538 - 12540 (2011)
For the first time, employment of nicotinamide coenzyme NAD analogs has overcome the limitations of NAD in electrochemical regeneration. It has been shown that NAD analogs, APAD and PAAD, were electrochemically reduced more efficiently than original NAD and that the stability of their reduced products was also much higher than NADH.
WS2/g-C3N4 composite as an efficient heterojunction photocatalyst for biocatalyzed artificial photosynthesis
Zeng, Peng,Ji, Xiaoyuan,Su, Zhiguo,Zhang, Songping
, p. 20557 - 20567 (2018)
A heterogeneous WS2/g-C3N4 composite photocatalyst was prepared by a facile ultrasound-assisted hydrothermal method. The WS2/g-C3N4 composite was used for photocatalytic regeneration of NAD+ to NADH, which were coupled with dehydrogenases for sustainable bioconversion of CO2 to methanol under visible light irradiation. Compared with pristine g-C3N4 and the physical mixture of WS2 and g-C3N4, the fabricated WS2/g-C3N4 composite catalyst with 5 wt% of WS2 showed the highest activity for methanol synthesis. The methanol productivity reached 372.1 μmol h-1 gcat-1, which is approximately 7.5 times higher than that obtained using pure g-C3N4. For further application demonstration, the activity of the WS2/g-C3N4 composite catalyst toward photodegradation of Rhodamine B (RhB) was evaluated. RhB removal ratio approaching 100% was achieved in 1 hour by using the WS2/g-C3N4 composite catalyst with 5 wt% of WS2, at an apparent degradation rate approximately 2.6 times higher than that of pure g-C3N4. Based on detailed investigations on physiochemical properties of the photocatalysts, the significantly enhanced reaction efficiency of the WS2/g-C3N4 composite was considered to be mainly benefiting from the formation of a heterojunction interface between WS2 and g-C3N4. Upon visible-light irradiation, the photo-induced electrons can transfer from the conduction band of g-C3N4 to WS2, thus recombination of electrons and holes was decreased and the photo-harvesting efficiency was enhanced.
