Read by QxMD icon Read


Annamaria Ricciardi, Rocco Gerardo Ianniello, Eugenio Parente, Teresa Zotta
Catalases reduce oxidative stress by degrading hydrogen peroxide to molecular oxygen and water. The presence of heme-dependent or manganese-dependent catalases was observed for a long time in lactic acid bacteria (LAB) but, to date, knowledge on the factors affecting gene expression and enzymatic functionality are limited to a very few strains. In this study, the effect of atmosphere of incubation (not aerated static growth vs aerated shaken growth) and supplementation with Fe2+ , hemin, Mn2+ or their combinations on the catalase production of respiration-competent strain Lactobacillus casei N87 was evaluated using a 24 factorial design...
May 8, 2018: International Journal of Food Microbiology
Zhanmin Liu, Chenhui Yao, Cuiyun Yang, Yanming Wang, Sibao Wan, Junyi Huang
Listeria monocytogenes is an important food-borne pathogen, and it can cause severe diseases. Rapid detection of L. monocytogenes is crucial to control this pathogen. A simple and robust strategy based on the cascade of PCR and G-quadruplex DNAzyme catalyzed reaction was used to detect L. monocytogenes. In the presence of hemin and the aptamer formed during PCR, the catalytic horseradish peroxidase-mimicking G-quadruplex DNAzymes allow the colorimetric responses of target DNA from L. monocytogenes. This assay can detect genomic DNA of L...
May 16, 2018: Analytical Biochemistry
Hemin Oathman Sheriff, Kawa Abdullah Mahmood, Nzar Hamawandi, Aram Jamal Mirza, Jawad Hawas, Esther Granell Moreno, Juan Antonio Clavero, Christopher Hankins, Jaume Masia
BACKGROUND:  The supraclavicular artery flap is an excellent flap for head and neck reconstruction. The aim of this study is to assess imaging techniques to define the precise vascular boundaries of this flap. METHODS:  Six imaging techniques were used for supraclavicular artery mapping in 65 cases; handheld Doppler, triplex ultrasound, computed tomography angiography, magnetic resonance angiography, digital subtraction angiography, and indocyanine green angiography...
May 18, 2018: Journal of Reconstructive Microsurgery
Pingdan Yan, Yixiong Hao, Zhaoche Shu, Chunling Gu, Xiaomei Zhou, Xiaoyu Liu, Hua Xiang
The authors describe a novel assay for the detection of methylated DNA site. Rolling circle amplification and CdSe/ZnS quantum dots with high fluorescence efficiency are applied in this method. The CdSe/ZnS quantum dots act as electron donors, and hemin and oxygen (derived from hydrogen peroxide act as acceptors in photoinduced electron transfer. The assay, best performed at excitation/emission peaks of 450/620 nm, is sensitive and specific. Fluorometric response is linear in the 1 pM to 100 nM DNA concentration range, and the lowest detectable concentration of methylated DNA is 142 fM (S/N = 3)...
May 13, 2018: Mikrochimica Acta
Tuan Anh Nguyen, Joha Park, Thi Lieu Dang, Yeon-Gil Choi, V Narry Kim
Microprocessor, which consists of a ribonuclease III DROSHA and its cofactor DGCR8, initiates microRNA (miRNA) maturation by cleaving primary miRNA transcripts (pri-miRNAs). We recently demonstrated that the DGCR8 dimer recognizes the apical elements of pri-miRNAs, including the UGU motif, to accurately locate and orient Microprocessor on pri-miRNAs. However, the mechanism underlying the selective RNA binding remains unknown. In this study, we find that hemin, a ferric ion-containing porphyrin, enhances the specific interaction between the apical UGU motif and the DGCR8 dimer, allowing Microprocessor to achieve high efficiency and fidelity of pri-miRNA processing in vitro...
May 10, 2018: Nucleic Acids Research
Rachel P L van Swelm, Madelon Vos, Frank Verhoeven, Frank Thévenod, Dorine W Swinkels
Hemoglobinuria is associated with kidney injury in various hemolytic pathologies. Currently, there is no treatment available and its pathophysiology is not completely understood. Here we studied the potential detrimental effects of hemoglobin (Hb) exposure to the distal nephron (DN). Involvement of the DN in Hb kidney injury was suggested by the induction of renal hepcidin synthesis (p < 0.001) in mice repeatedly injected with intravenous Hb. Moreover, the hepcidin induction was associated with a decline in urinary kidney injury markers 24p3/NGAL and KIM1, suggesting a role for hepcidin in protection against Hb kidney injury...
May 10, 2018: Cell Death & Disease
Tianmu Hu, Anwar Saeed Ahmed Qahtan, Lei Lei, Zhixin Lei, Dapeng Zhao, Hemin Nie
In order to improve the release pattern of chemotherapy drug and reduce the possibility of drug resistance, poly(ethylene glycol amine) (PEG)-modified alginate microparticles (ALG-PEG MPs) were developed then two different mechanisms were employed to load doxorubicin (Dox): 1) forming Dox/ALG-PEG complex by electrostatic attractions between unsaturated functional groups in Dox and ALG-PEG; 2) forming Dox-ALG-PEG complex through EDC-reaction between the amino and carboxyl groups in Dox and ALG, respectively...
March 2018: Bioactive Materials
Lvping Cai, Liyun Deng, Xiangyi Huang, Jicun Ren
Chemiluminescence (CL) is a promising bioimaging method due to no interferences of light source and autofluorescence. However, compared to fluorescent emission, most CL reactions show short emission time and wavelength and weak emission intensity, which limit their applications in in vivo imaging. Here, we report mimic-enzyme catalytic CL polymer dots (hemin-Pdots) consisting of hemin and fluorescent conjugated polymer based on chemiluminescence resonance energy transfer. Hemin-Pdots show about 700-times enhanced CL and over10 hour light emission in the presence of CL substrates and H2O2...
May 7, 2018: Analytical Chemistry
Christopher S Spencer, Cristina Yunta, Glauber Pacelli Gomes de Lima, Kay Hemmings, Lu-Yun Lian, Gareth Lycett, Mark J I Paine
The mosquito Anopheles gambiae is the principal vector for malaria in sub-Saharan Africa. The ability of A. gambiae to transmit malaria is strictly related to blood feeding and digestion, which releases nutrients for oogenesis, as well as substantial amounts of highly toxic free heme. Heme degradation by heme oxygenase (HO) is a common protective mechanism, and a gene for HO exists in the An. gambiae genome HO (AgHO), although it has yet to be functionally examined. Here, we have cloned and expressed An. gambiae HO (AgHO) in E...
May 2, 2018: Insect Biochemistry and Molecular Biology
Victoria Shumyantseva, Tatiana Bulko, Alexey Kuzikov, Rami Masamrekh, Alexander Archakov
Method for electrochemical determination of L-tyrosine with screen-printed electrodes (SPE) modified with multi-walled CNT or CNT/TiO2 as sensing elements was used for the electroanalysis of L-tyrosine (Tyr). It was demonstrated that SPE/CNT and SPE/CNT/TiO2 exhibited high electrocatalytic activity and good analytical performance towards oxidation of L-tyrosine. The linear range of Tyr in human serum was 0.025 ÷ 1 mM with the correlation coefficient R2  = 0.97. Direct electrochemistry (without any mediator) of co-factor-free bovine serum albumin (BSA) and human serum albumin (HSA) was investigated by use of modified electrodes...
May 3, 2018: Amino Acids
Lara Villarino, Kathryn Splan, Eswar Reddem, Cora Gutiérrez de Souza, Lur Alonso-Cotchico, Agustí Lledós, Jean-Didier Maréchal, Andy-Mark Thunnissen, Gerard Roelfes
An artificial heme enzyme was created by self-assembly from hemin and the Lactococcal multidrug resistance Regulator (LmrR). The crystal structure shows the heme bound inside the hydrophobic pore of the protein, where it appears inaccessible for substrates. Yet, good catalytic activity and moderate enantioselectivity was observed in the abiological cyclopropanation reaction. We proposed that the dynamic nature of the structure of the LmrR protein is key to the observed activity. This was supported by molecular dynamics simulations, which showed transient formation of opened conformations allowing for binding of substrates and formation of pre-catalytic structures...
May 2, 2018: Angewandte Chemie
Tingting Ai, Qiufang Yang, You Lv, Yuqin Huang, Yuzhi Li, Jia Geng, Dan Xiao, Cuisong Zhou
The oxidative damage toxic property of G-quadruplex (G4), linked to neurodegenerative diseases, may arise from their ability to bind and oxidatively activate cellular hemin. However, there have been no precise studies on how telomeric G4 enhances the low intrinsic peroxidase activity of hemin. Herein, a label-free and nanopore-based strategy was developed to explore the enhancement mechanism of peroxidase activity of hemin induced by telomeric G4 (d(TTAGGG)n). The nanopore-based strategy demonstrated that there were simultaneously two different binding modes of telomere G4 to hemin...
May 2, 2018: Chemistry, An Asian Journal
Patmawati Xxxx, Kosuke Minamihata, Tsuneyuki Tatsuke, Jae Man Lee, Takahiro Kusakabe, Noriho Kamiya
Recombinant protein production can create artificial proteins with desired functions by introducing genetic modifications to the target proteins. Horseradish peroxidase (HRP) has been used extensively as a reporter enzyme in biotechnological applications; however, recombinant production of HRP has not been very successful, hampering the utilization of HRP with genetic modifications. A fusion protein comprising an antibody binding protein and HRP will be an ideal bio-probe for high-quality HRP-based diagnostic systems...
March 25, 2018: Biotechnology Journal
James H Campbell, John J Heikkila
Cadmium is a highly toxic environmental pollutant that can cause many adverse effects including cancer, neurological disease and kidney damage. Aquatic amphibians are particularly susceptible to this toxicant as it was shown to cause developmental abnormalities and genotoxic effects. In mammalian cells, the accumulation of heme oxygenase-1 (HO-1), which catalyzes the breakdown of heme into CO, free iron and biliverdin, was reported to protect cells against potentially lethal concentrations of CdCl2 . In the present study, CdCl2 treatment of A6 kidney epithelial cells, derived from the frog, Xenopus laevis, induced the accumulation of HO-1, heat shock protein 70 (HSP70) and HSP30 as well as an increase in the production of aggregated protein and aggresome-like structures...
April 23, 2018: Comparative Biochemistry and Physiology. Toxicology & Pharmacology: CBP
Wang Shan, Liang Yue, Zi-Yuan Li, Junji Zhang, He Tian, Itamar Willner
The light-induced reversible and cyclic reconfiguration of constitutional dynamic networks, consisting of supramolecular nucleic acid structures as constituents and a photoisomerizable trans-/cis- azobenzene-functionalized nucleic acid as trigger is demonstrated. In addition, the cyclic photochemical reconfiguration of the constitutional dynamic networks guides the switchable "ON"/"OFF" operation of an emerging hemin/G-quadruplex DNAzyme.
April 26, 2018: Angewandte Chemie
Olga Mucha, Paulina Podkalicka, Maria Czarnek, Anna Biela, Mateusz Mieczkowski, Neli Kachamakova-Trojanowska, Jacek Stepniewski, Alicja Jozkowicz, Jozef Dulak, Agnieszka Loboda
Inhibition of heme oxygenase-1 (HO-1, encoded by HMOX1), a cytoprotective, anti-apoptotic and anti-inflammatory enzyme, may serve as a valuable therapy in various pathophysiological processes, including tumorigenesis. We compared the effect of chemical inhibitors - metalloporphyrins, with genetic tools - shRNA and CRISPR/Cas9 systems, to knock-down (KD)/knock-out (KO) HO-1 expression/activity. 293T cells were incubated with metalloporphyrins, tin and zinc protoporphyrins (SnPPIX and ZnPPIX, respectively) or were either transduced with lentiviral vectors encoding different shRNA sequences against HO-1 or were modified by CRISPR/Cas9 system targeting HMOX1...
April 25, 2018: Acta Biochimica Polonica
Sushma Chauhan, Taek Jin Kang
Horseradish peroxidase (HRP) is widely used as a marker enzyme in immunoassays and biosensors, and can possibly be used in industries such as waste water treatments or fine chemical synthesis. Cost-effective production of active HRP is thus very important in the related fields. Also, engineering of HRP for its better performance in the designated application is expected to make the enzyme even more important in several areas of research and industry. One of obstacles to this end and to the large scale production of the enzyme has been its facile expression in a bacterial host...
April 21, 2018: Journal of Bioscience and Bioengineering
Xiaofan Sun, Haohan Chen, Shuling Wang, Yiping Zhang, Yaping Tian, Nandi Zhou
A high-sensitive detection of sequence-specific DNA was established based on the formation of G-quadruplex-hemin complex through continuous hybridization chain reaction (HCR). Taking HIV DNA sequence as an example, a capture probe complementary to part of HIV DNA was firstly self-assembled onto the surface of Au electrode. Then a specially designed assistant probe with both terminals complementary to the target DNA and a G-quadruplex-forming sequence in the center was introduced into the detection solution...
August 27, 2018: Analytica Chimica Acta
Xinhui Yu, Yaohui Lin, Xusheng Wang, Liangjun Xu, Zongwen Wang, FengFu Fu
An exonuclease-assisted multicolor aptasensor was developed for the visual detection of ochratoxin A (OTA). It is based on the etching of gold nanorods (AuNRs) mediated by a G-quadruplex-hemin DNAzyme. A DNA sequence (AG4-OTA) was designed that comprises a hemin aptamer and an OTA aptamer. OTA binds to AG4-OTA to form an antiparallel G-quadruplex, which halts its digestion by exonuclease I (Exo I) from the 3'-end of AG4-OTA. Thus, the retained hemin aptamer can bind to hemin to form a G-quadruplex-hemin DNAzyme...
April 21, 2018: Mikrochimica Acta
Chun Hong Yu, Liang Jiang, Ying Wang, Ning Xuan Cui, Xiao Zhao, Zong Chun Yi
This study investigated the effects of N-acetylcysteine (NAC) and ascorbic acid (AA) on hemin-induced K562 cell erythroid differentiation and the role of reactive oxygen species (ROS) in this process. Hemin increased ROS levels in a concentration-dependent manner, whereas NAC and AA had opposite effects. Both NAC and AA eliminated transient increased ROS levels after hemin treatment, inhibited hemin-induced hemoglobin synthesis, and decreased mRNA expression levels of β-globin, γ-globin, and GATA-1 genes significantly...
March 2018: Biomedical and Environmental Sciences: BES
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"