Heterogeneity of Equilibrium Molten Globule State of Cytochrome c Induced by Weak Salt Denaturants under Physiological Condition

While many proteins are recognized to undergo folding via intermediate(s), the heterogeneity of equilibrium folding intermediate(s) along the folding pathway is less understood. In our present study, FTIR spectroscopy, far- and near-UV circular dichroism (CD), ANS and tryptophan fluorescence, near IR absorbance spectroscopy and dynamic light scattering (DLS) were used to study the structural and thermodynamic characteristics of the native (N), denatured (D) and intermediate state (X) of goat cytochorme c (cyt-c) induced by weak salt denaturants (LiBr, LiCl and LiClO₄) at pH 6.0 and 25°C. The LiBr-induced denaturation of cyt-c measured by Soret absorption (Δε ₄₀₀) and CD ([θ]₄₀₉), is a three-step process, N ↔ X ↔ D. It is observed that the X state obtained along the denaturation pathway of cyt-c possesses common structural and thermodynamic characteristics of the molten globule (MG) state. The MG state of cyt-c induced by LiBr is compared for its structural and thermodynamic parameters with those found in other solvent conditions such as LiCl, LiClO₄ and acidic pH. Our observations suggest: (1) that the LiBr-induced MG state of cyt-c retains the native Met80-Fe(III) axial bond and Trp59-propionate interactions; (2) that LiBr-induced MG state of cyt-c is more compact retaining the hydrophobic interactions in comparison to the MG states induced by LiCl, LiClO₄ and 0.5 M NaCl at pH 2.0; and (3) that there exists heterogeneity of equilibrium intermediates along the unfolding pathway of cyt-c as highly ordered (X1), classical (X2) and disordered (X3), i.e., D ↔ X3 ↔ X2 ↔ X1 ↔ N.     

Brucellosis and Coxiella burnetii Infection in Householders and Their Animals in Secure Villages in Herat Province,Afghanistan: A Cross-Sectional Study

Background

Brucellosis and coxiellosis are known to be endemic in ruminant populations throughout Afghanistan, but information about their prevalence and factors that affect prevalence in householders and livestock under diverse husbandry systems and pastoral settings is sparse.

Methods/Principal Findings

We conducted a cross-sectional survey to investigate the seroprevalence of brucellosis and Coxiella burnetii in humans and livestock in six secure districts in Herat from 26^th December 2012–17^th January 2013. A total of 204 households with livestock were surveyed in six Kuchi and five sedentary type villages. Blood samples from 1,017 humans, 1,143 sheep, 876 goats and 344 cattle were tested for brucellosis and Q fever. About one in six households (15.7%) had at least one Brucella seropositive person, about one in eight households (12.3%) had at least one Brucella seropositive animal and about one in four (24.5%) had either seropositive animals or humans. Ninety-seven percent of households had at least one C. burnetii seropositive person and 98.5% of households had one or more C. burnetii seropositive animals. Forty- seven householders had serological evidence of exposure to both C. burnetii and Brucella and eight animals were serologically positive for both diseases. Drinking unpasteurised milk (OR 1.6), treating animals for ticks (OR 1.4), milking sheep (OR 1.4), male gender (OR 1.4) and seropositivity to Brucella (OR 4.3) were identified as risk factors for seropositivity to C. burnetii in householders. Household factors associated with households having either Brucella seropositive animals or humans were Kuchi households (OR 2.5), having ≤4 rooms in the house (OR 2.9) and not owning land (OR 2.9).

Conclusions

The results from this study provide baseline information for the planning and monitoring of future interventions against these diseases. The implementation of this study greatly improved collaboration, coordination and capability of veterinary and public health professionals from government, NGOs and donor funded projects.     

Geochemical Speciation and Risk Assessment of Heavy Metals in Sediments of a River in Bangladesh

The surface sediment of a downstream river (Paira) connected to the marine ecosystems of the Bay of Bengal was assessed by sequential extraction technique. The objectives of this study were to evaluate the mobility and dynamics of heavy metals and their probable ecological risks. The results revealed high environmental risk of Cd due to higher availability in the exchangeable fraction (21%) and a considerable portion in the carbonate bound fraction due to the special affinity towards carbonate and co-precipitation with its minerals. Toxic metals like Cr, Ni, and Cd are of concern, and can occasionally be associated with adverse biological effects. The risk assessment code (RAC) suggests that the highest mobility of Cd poses a higher environmental risk and threat to the aquatic biota, as well.     

Multigenic and morphometric differentiation of ground squirrels (Spermophilus, Scuiridae, Rodentia) in Turkey, with a description of a new species

This study reports on the molecular phylogenetics of ground squirrels, genus Spermophilus, in Turkey using cytochrome b (1140bp), part of the D-loop and flanking tRNAs (572bp), X chromosome (867-1051bp) and Y chromosome (983-989bp) DNA sequences. Individuals also were characterized by karyotype and with geometric morphometric analyses of mandibles and skulls. Two hundred fourteen individuals from 91 localities were studied. All the data support the recognition of a new species in SW Anatolia: the Taurus ground squirrel Spermophilus taurensis sp. nov. The new species has a small distribution in the Taurus Mountains in an area that is a hotspot for biodiversity. Molecular clock analysis suggests that the new species diverged from the European ground squirrel, Spermophilus citellus, about 2.5 million years ago and that the ancestor of these two species diverged from the widespread Anatolian ground squirrel, Spermophilus xanthoprymnus, about 5 million years ago. Morphometric differentiation in skull and mandible shape among the three species is incomplete, but statistically significant. S. xanthoprymnus is subdivided into five cytochrome b phylogroups and we use these data to infer the location of glacial refugia where the species lived during the last glacial maximum. This study illustrates the potential of combined molecular and morphometric studies to uncover new Anatolian species and to reconstruct their phylogeographic history. The new species is important for squirrel taxonomy and for understanding Eurasian mammal evolution.     

Carbon and nitrogen pools in a mangrove stand of <Emphasis Type="Italic">Kandelia obovata</Emphasis> (S., L.) Yong: vertical distribution in the soil–vegetation system

Attempts were made to quantify the carbon and nitrogen pools in a monospecific and pioneer mangrove stand of Kandelia obovata Sheue, Liu & Yong, Okinawa Island, Japan. The leaf C and N concentrations on a leaf area basis decreased with increasing PPFD (Photosysthetic Photon Flux Density). The total C and N stocks in foliage were estimated as 3.55 Mg ha^–1 and 0.105 Mg ha^–1, respectively. The bark (45.6–48.6% for C and 0.564–0.842% for N) contained significantly higher amount of C (P < 0.05) and N (P < 0.01) than wood (46.2–47.8% for C and 0.347–0.914% N). The total C stock of stem was 23.2 Mg ha^–1 in wood and 8.33 Mg ha^–1 in bark, and the total N stock was 0.222 Mg ha^–1 in wood and 0.116 Mg ha^–1 in bark. The root wood (37.1–45.0%) contained significantly higher amount of C than root bark (35.4–40.7%) (P < 0.01). The total C stock of root was 14.2 Mg ha^–1 in wood and 12.6 Mg ha^–1 in bark, and the total N stock of root was 0.157 Mg ha^–1 in wood and 0.155 Mg ha^–1 in bark. The soil organic C and total N stocks within 1 m soil depth were estimated as 57.3 Mg ha^–1 and 2.73 Mg ha^–1, respectively. The C pool in aboveground biomass (35.1 Mg ha^–1) was 1.3 times as large as that in belowground biomass (26.9 Mg ha^–1). However, the soil organic C pool (57.3 Mg ha^–1) was similar to the total C pool (62.0 Mg ha^–1) of vegetation, indicating that the mangrove stored a large part of production in the soil. About 50% of the C was in the soil. The N pool in aboveground biomass (0.442 Mg ha^–1) was 1.4 times as large as that in belowground biomass (0.312 Mg ha^–1). The soil N stock was 3.3 times as large as the biomass N stock (0.754 Mg ha^–1).     

Indolinone based phosphoinositide-dependent kinase-1 (PDK1) inhibitors. Part 1: design, synthesis and biological activity

HTS screening identified 1 with micromolar inhibitory activity against PDK1. Optimization of 1 afforded 4i (BX-517) which has single-digit nanomolar activity against PDK1 and excellent selectivity against PKA.     

Characterization of lignin isolated from some nonwood available in Bangladesh

Lignins isolated from cotton stalks, jute stick and dhaincha by acidolytic dioxane were characterized using alkaline nitrobenzene oxidation, elemental analysis, methoxyl analysis and molecular weight analysis and UV, IR (1)H NMR spectroscopy. The C(9) formulas for cotton stalks, jute stick and dhaincha (Sesbania aculeata) lignin were C(9)H(9.36)O(4.50)(OCH(3))(1.23), C(9)H(9.02)O(4.57)(OCH(3))(1.35) and C(9)H(8.88)O(4.65)(OCH(3))(1.50), respectively. All three lignins were of the guaiacyl-syringyl type. Cotton stalks lignin contained more p-hydroxy phenyl unit than dhaincha and jute stick lignins as observed by alkaline nitrobenzene oxidation products. The beta-O-4 units in these nonwood lignins had predominately erythro stereochemistry type.     

Indolinone based phosphoinositide-dependent kinase-1 (PDK1) inhibitors. Part 2: optimization of BX-517

Based on the lead compound BX-517, a series of C-4' substituted indolinones have been synthesized and evaluated for PDK1 inhibition. Modification at C-4' of the pyrrole afforded potent compounds (7b and 7d) with improved solubility and ADME properties. In this letter, we describe the synthesis, selectivity profile, and pharmacokinetic data of selected compounds.     

Distribution and diet of the roughskin sculpin, <Emphasis Type="Italic">Trachidermus fasciatus</Emphasis>, larvae and juveniles in the Chikugo River estuary,Ariake Bay,Japan

Larvae and juveniles of the roughskin sculpin Trachidermus fasciatus were collected during four cruises in March and April 2001 to study the distribution and diet of the fish in the Chikugo estuary in the northern Ariake Bay, Japan. Sampling was conducted at seven stations covering an area approximately 30 km in length along the estuary, with salinity ranging from nearly 0 to about 30 PSU. Gut contents were analyzed by separating, identifying, and counting the prey organisms. Plankton samples were collected during each cruise to study the numerical composition and abundance of copepods in ambient water. A total of 1790 larvae and juveniles of T. fasciatus were collected; they were distributed in the five uppermost stations, covering approximately 20 km and ranging in salinity from 0.4 to 27.4 PSU. The fish fed almost exclusively on a single calanoid copepod species, Sinocalanus sinensis, which was numerically the most abundant in the ambient water at the upper part of the Chikugo River. At the lower part of the river, the fish positively selected S. sinensis while negatively selecting other species. T. fasciatus larvae experienced a high proportion of empty guts and low feeding intensity at around 9.0 mm body length, which appears to be associated with commencement of exogenous feeding. The proportion of empty guts reduced sharply at subsequent stages and was accompanied by an increase in feeding intensity. The oligohaline and mesohaline areas are important nursery grounds, and S. sinensis is an important prey copepod species for the larval and juvenile T. fasciatus in the Chikugo estuary.     

Proteomic analysis of plasma membrane and secretory vesicles from human neutrophils

Background  

Polymorphonuclear neutrophils (PMN) constitute an essential cellular component of innate host defense against microbial invasion and exhibit a wide array of responses both to particulate and soluble stimuli. As the cells recruited earliest during acute inflammation, PMN respond rapidly and release a variety of potent cytotoxic agents within minutes of exposure to microbes or their products. PMN rely on the redistribution of functionally important proteins, from intracellular compartments to the plasma membrane and phagosome, as the means by which to respond quickly. To determine the range of membrane proteins available for rapid recruitment during PMN activation, we analyzed the proteins in subcellular fractions enriched for plasma membrane and secretory vesicles recovered from the light membrane fraction of resting PMN after Percoll gradient centrifugation and free-flow electrophoresis purification using mass spectrometry-based proteomics methods.