Unraveling Comparative Anti-Amyloidogenic Behavior of Pyrazinamide and D-Cycloserine: A Mechanistic Biophysical Insight

Amyloid fibril formation by proteins leads to variety of degenerative disorders called amyloidosis. While these disorders are topic of extensive research, effective treatments are still unavailable. Thus in present study, two anti-tuberculosis drugs, i.e., pyrazinamide (PYZ) and D-cycloserine (DCS), also known for treatment for Alzheimer’s dementia, were checked for the anti-aggregation and anti-amyloidogenic ability on Aβ-42 peptide and hen egg white lysozyme. Results demonstrated that both drugs inhibit the heat induced aggregation; however, PYZ was more potent and decelerated the nucleation phase as observed from various spectroscopic and microscopic techniques. Furthermore, pre-formed amyloid fibrils incubated with these drugs also increased the PC12/SH-SY5Y cell viability as compare to the amyloid fibrils alone; however, the increase was more pronounced for PYZ as confirmed by MTT assay. Additionally, molecular docking study suggested that the greater inhibitory potential of PYZ as compare to DCS may be due to strong binding affinity and more occupancy of hydrophobic patches of HEWL, which is known to form the core of the protein fibrils.     

MVA recombinants expressing the fusion and hemagglutinin genes of PPRV protects goats against virulent challenge

Peste des Petits Ruminants (PPR) is a highly contagious animal disease caused by the Peste des Petits Ruminants virus (PPRV) belonging to the genus morbillivirus and family Paramyxoviridae. The disease results in high morbidity and mortality in goats, sheep and in some small wild ruminants. The presence of large number of small ruminants reared in endemic areas makes PPR a notorious disease threatening the livelihood of poor farmers. Conventional vaccination using a live, attenuated vaccine gives adequate protection but cannot be used in case of eradication of the disease due to difficulty in differentiation of infected animals from the vaccinated ones.     

Association of serum markers with improvement in clinical response measures after treatment with golimumab in patients with active rheumatoid arthritis despite receiving methotrexate: results from the GO-FORWARD study

Introduction  

The goal of this study was to identify serum markers that are modulated by treatment with golimumab with or without methotrexate (MTX) and are associated with clinical response.     

Inbred and outbred mice have equivalent variability in a cockroach allergen-induced model of asthma

Outbred mice traditionally are considered to display high variability, thereby limiting their use in some studies. Researchers frequently are encouraged to use inbred strains of mice because of the greater homogeneity of these experimental animals. We compared the pulmonary inflammatory response of inbred BALB/cJ mice to that of outbred HSD-ICR mice by measuring multiple variables, including cytokines, chemokines, number of pulmonary inflammatory cells, and respiratory parameters. Cockroach allergens induced significant pulmonary inflammation in both BALB and ICR mice. Our comparisons of the coefficients of variance for 148 discrete data sets for each strain or stock indicated that BALB and ICR mice have roughly equivalent intrastrain or -stock variability in our model of asthma-like pulmonary inflammation. The average coefficient of variance, calculated as the ratio of the SD to the mean of a data set, was 0.35 ± 0.34 for BALB mice compared with 0.31 ± 0.32 for ICR mice. In conclusion, inbred BALB and outbred ICR mice have roughly equivalent intrastrain or -stock variability in a murine model of asthma-like pulmonary inflammation.     

Role of activated macrophages in Acanthamoeba keratitis

The purpose of this study was to determine whether activating the conjunctival macrophages would affect the course of Acanthamoeba spp. keratitis in a Chinese hamster model of this disease. Chinese hamster spleen cells were stimulated with concanavalin A (Con A), and interferon gamma (IFN-gamma) -containing supernatants were collected 24 hr later. The IFN-gamma-containing supernatants were loaded into liposomes, which were fed to peritoneal macrophages in vitro. Macrophage activation was assessed by testing for production of nitric oxide (NO) with the use of Griess reagent. Conjunctival macrophages were activated in situ by subconjunctival injection of liposomes containing Con A-activated spleen cell culture supernatants. Control liposomes were loaded with phosphate-buffered saline (PBS). Macrophages exposed to supernatants from Con A-stimulated spleen cells produced 4-fold-higher amounts of NO than unstimulated macrophages. Activation of macrophages via subconjunctival injection of liposomes containing supernatants from Con A-stimulated spleen cell cultures resulted in rapid resolution of the corneal infection. Approximately 80% of animals treated with PBS-containing liposomes demonstrated evidence of corneal disease at day 14 compared to 10% incidence of infection in the Con A-treated group. Moreover, at all time points examined, the clinical appearance of the keratitis in animals treated with liposomes containing Con A supernatant was significantly reduced compared to the group treated with liposomes containing PBS (P < 0.05). Macrophages stimulated with IFN-gamma-containing supernatants killed significant numbers of the trophozoites in vitro (P < 0.05). Killing was inhibited by cytochalasin D, but not by L-N6-1-iminoethyl-L-lysine dihydrochloride (L-NIL), which is a selective inhibitor of inducible NO synthase (INOS).     

Ion pairs in non-redundant protein structures

Ion pairs contribute to several functions including the activity of catalytic triads, fusion of viral membranes, stability in thermophilic proteins and solvent-protein interactions. Furthermore, they have the ability to affect the stability of protein structures and are also a part of the forces that act to hold monomers together. This paper deals with the possible ion pair combinations and networks in 25% and 90% non-redundant protein chains. Different types of ion pairs present in various secondary structural elements are analysed. The ion pairs existing between different subunits of multisubunit protein structures are also computed and the results of various analyses are presented in detail. The protein structures used in the analysis are solved using X-ray crystallography, whose resolution is better than or equal to 1.5 A and R-factor better than or equal to 20%. This study can, therefore, be useful for analyses of many protein functions. It also provides insights into the better understanding of the architecture of protein structure.     

Antifungal susceptibility profiles of <Emphasis Type="Italic">Coccidioides immitis</Emphasis> and <Emphasis Type="Italic">Coccidioides posadasii</Emphasis> from endemic and non-endemic areas

Coccidioidomycosis is a systemic fungal infection endemic in Southwestern United States, Mexico, Central and South America. The causal agents are Coccidioides immitis and C. posadasii. A large number of cases of coccidioidomycosis in New York State residents were identified. We compared susceptibility profiles of these isolates and of C. immitis isolates from California using mycelial phase inoculum and CLSI (NCCLS) M38–A broth microdilution protocol. Minimum fungicidal concentrations (MFC) were also determined. Results indicated that geometric mean MICs of amphotericin B (AMB, 0.06 μg/ml), fluconazole (FLC, 8.0 μg/ml), itraconazole (ITC, 0.07 μg/ml), ketoconazole (KTC, 0.04 μg/ml), voriconazole (VRC, 0.04 μg/ml), posaconazole (PSC, 0.17 μg/ml) and caspofungin (CSP, 0.15 μg/ml) were in susceptible range as per breakpoints published for pathogenic Candida species. However, geometric MFC for FLC was relatively higher (52.4 μg/ml). Also, no significant difference in MIC and MFC values was evident for C. immitis and C. posadasii isolates. In conclusion, current methods for antifungal susceptibility testing yield reproducible profiles for Coccidioides species, which appear to be highly susceptible to most antifungal agents.     

Investigations on unconventional hydrogen bonds in RNA binding proteins: the role of CH...O=C interactions

We have investigated the roles played by C-H...O=C interactions in RNA binding proteins. There was an average of 78 CH...O=C interactions per protein and also there was an average of one significant CH...O=C interactions for every 6 residues in the 59 RNA binding proteins studied. Main chain-Main chain (MM) CH...O=C interactions are the predominant type of interactions in RNA binding proteins. The donor atom contribution to CH...O=C interactions was mainly from aliphatic residues. The acceptor atom contribution for MM CH...O=C interactions was mainly from Val, Phe, Leu, Ile, Arg and Ala. The secondary structure preference analysis of CH...O=C interacting residues showed that, Arg, Gln, Glu and Tyr preferred to be in helix, while Ala, Asp, Cys, Gly, Ile, Leu, Lys, Met, Phe, Trp and Val preferred to be in strand conformation. Most of the CH...O=C interacting polar amino acid residues were solvent exposed while, majority of the CH...O=C interacting non polar residues were excluded from the solvent. Long and medium-range CH...O=C interactions are the predominant type of interactions in RNA binding proteins. More than 50% of CH...O=C interacting residues had a higher conservation score. Significant percentage of CH...O=C interacting residues had one or more stabilization centers. Sixty-six percent of the theoretically predicted stabilizing residues were also involved in CH...O=C interactions and hence these residues may also contribute additional stability to RNA binding proteins.