A Novel Electrochemical Sensor Modified with a Computer-Simulative Magnetic Ion-Imprinted Membrane for Identification of Uranyl Ion.

In this paper, a novel ion-imprinted electrochemical sensor modified with magnetic nanomaterial FeO@SiO was established for the high sensitivity and selectivity determination of UO in the environment. Density functional theory (DFT) was employed to investigate the interaction between templates and binding ligands to screen out suitable functional binding ligand for the reasonable design of the ion imprinted sensors. The MIIP/MCPE (magnetic ion imprinted membrane/magnetic carbon paste electrode) modified with FeO@SiO exhibited a strong response current and high sensitivity toward uranyl ion comparison with the bare carbon paste electrodes.

Species identification and phylogenetic analysis of Leishmania isolated from patients, vectors and hares in the Xinjiang Autonomous Region, The People's Republic of China.

Background: Visceral leishmaniasis (VL) has been declared as one of the six major tropical diseases by the World Health Organization. This disease has been successfully controlled in China, except for some areas in the western region, such as the Xinjiang Autonomous Region, where both anthroponotic VL (AVL) and desert type zoonotic VL (DT-ZVL) remain endemic with sporadic epidemics.

Methodology/principal Findings: Here, an eleven-year survey (2004-2014) of Leishmania species, encompassing both VL types isolated from patients, sand-fly vectors and Tarim hares (Lepus yarkandensis) from the Xinjiang Autonomous Region was conducted, with a special emphasis on the hares as a potential reservoir animal for DT-ZVL.

[Pathogen Identification in an Imported Case of Cutaneous Leishmaniasis].

In this study, immune and molecular biological methods were used to identify the pathogen in a blood sample from a patient with dermatosis. Venous blood was collected and tested with Leish rK39 dipsticks. The lesion sample was collected and fixed in 75% ethanol, and DNA was extracted.

Visceral Leishmaniasis in China: an Endemic Disease under Control.

Visceral leishmaniasis (VL) caused by Leishmania spp. is an important vector-borne and largely zoonotic disease. In China, three epidemiological types of VL have been described: anthroponotic VL (AVL), mountain-type zoonotic VL (MT-ZVL), and desert-type ZVL (DT-ZVL).

Observation of heme transfer from cytochrome b5 to DNA aptamer.

Heme transfer is commonly observed from one heme protein to the other such as from cytochrome b(5) (cyt b(5)) to apo-myoglobin. In this study, instead of to another heme protein, we observed the heme transfer from wild-type (WT) cyt b(5), H39C cyt b(5) with heme axial ligand His39 mutated to Cys39, and DME cyt b(5) with heme replaced by protoporphyrin IX dimethyl ester, to a heme DNA aptamer, PS2.M, respectively, with a different rate constant.

Rational design of a nitrite reductase based on myoglobin: a molecular modeling and dynamics simulation study.

Myoglobin (Mb) is an ideal scaffold protein for rational protein design mimicking native enzymes. We recently designed a nitrite reductase (NiR) based on sperm whale Mb by introducing an additional distal histidine (Leu29 to His29 mutation) and generating a distal tyrosine (Phe43 to Tyr43 mutation) in the heme pocket, namely L29H/F43Y Mb, to mimic the active site of cytochrome cd (1) NiR from Ps. aeruginosa that contains two distal histidines and one distal tyrosine.

Molecular modeling of cytochrome b₅ with a single cytochrome c-like thioether linkage.

Bovine liver cytochrome b (5) (cyt b (5)), with heme bound noncovalently, has been converted into a cyt c-like protein (cyt b (5) N57C) by constructing a thioether linkage between the heme and the engineered cysteine residue. With no X-ray or NMR structure available, we herein performed a molecular modeling study of cyt b (5) N57C. On the other hand, using amino acid sequence information for a newly discovered member of the cyt b (5) family, domestic silkworm cyt b (5) (DS cyt b (5)), we predicted the protein structure by homology modeling in combination with MD simulation.

Dynamics comparison of two myoglobins with a distinct heme active site.

Sperm whale myoglobin (swMb) is a well-studied heme protein, both experimentally and theoretically. Comparatively, little attention has been paid to another member of Mb family, Aplysia limacina myoglobin (apMb). swMb and apMb have the same overall structure and perform the same biological function, i.

Interactions of uranyl ion with cytochrome b₅ and its His39Ser variant as revealed by molecular simulation in combination with experimental methods.

The biological toxicity of uranyl ion (UO (2) (2+) ) lies in interacting with proteins and disrupting their native functions. The structural and functional consequences of UO (2) (2+) interacting with cytochrome b (5) (cyt b (5)), a small membrane heme protein, and its heme axial ligand His39Ser variant, cyt b (5) H39S, were investigated both experimentally and theoretically. In experiments, although cyt b (5) was only slightly affected, UO (2) (2+) binding to cyt b (5) H39S with a K (D) of 2.

Molecular modeling and dynamics simulation of a histidine-tagged cytochrome b₅.

Although an affinity tag such as six consecutive histidines, (His)(6)-tag, has been widely used to obtain high quantity of recombinant proteins, little is known about its influences on heme proteins for lack of structural information. When (His)(6)-tag was introduced to the N-terminus of a small heme protein, cytochrome b(5), experimental results showed the resultant protein, (His)(6)-cyt b(5), has similar property and function to that of isolated cyt b(5). To provide structural information for this observation, we herein performed a structural prediction of (His)(6)-cyt b(5) by molecular modeling in combination with molecular dynamics simulation.

[Simultaneous determination of calcium and magnesium by calculative spectrophotometric complexometric titration].

A new spectrophotometric complexometric titration method coupled with chemometrics for the determination of mixtures of metal ions has been developed. In the method described here, the titrant is a mixture of EDTA and two indicators. In the process of titration, both the volumetric addition of titrant and the progress of titration reaction can be characterized simultaneously by chemometric calculation with the absorption spectra, and then the titration curves can be obtained.

[Determination of nitrotyrosine with catalytic spectrophotometry combining the substitution of nitroxyl by iodide].

The nitroxyl of nitrotyrosine can be substituted quantitatively by iodide when the nitroxyl is reduced to amino and then diazotized to diazonium. The iodide can be determined by catalytic spectrophotometric method with iodide-nitrous acid-arsenious acid system. Thus, a new catalytic spectrophotometric method combining the substitution of nitroxyl by iodide for the determination of nitrotyrosine has been established.

Meriones meridianus and Lagurus lagurus as alternative definitive hosts of Echinococcus multilocularis and E. granulosus.

The utilization of Meriones meridianus and Lagurus lagurus as alternative definitive hosts for Echinococcus multilocularis and E. granulosus was investingated. Tapeworm stage development of E.