Comparative insights using the molecular homology model of BDNF (Brain derived neurotrophic factor) of Varanus komodoensis and the known NGF (Nerve growth factor) structure of Naja atra

BDNF (Brain derived neurotrophic factor) is a secretion protein and a member of the neurotrophin family of growth factors.Structural and functional characterization of BDNF Varanus komodoensis is of interest while its structure remains unknown. Thus, ahomology molecular model of BDNF was constructed for gleaning possible structural insights. The model was compared with thestructure of the homologous NGF (Nerve growth factor, another member of neuro-trophin family) from Naja atra. Comparativestructural analysis of the models showed structural similarities with their predicted cavities for the interpretation of potentialfunctional analogy.     

A leaf-based regeneration and transformation system for maize (<Emphasis Type="Italic">Zea mays</Emphasis> L.)

Efficient methods for in vitro propagation, regeneration, and transformation of plants are of pivotal importance to both basic and applied research. While being the world’s major food crops, cereals are among the most difficult-to-handle plants in tissue culture which severely limits genetic engineering approaches. In maize, immature zygotic embryos provide the predominantly used material for establishing regeneration-competent cell or callus cultures for genetic transformation experiments. The procedures involved are demanding, laborious and time consuming and depend on greenhouse facilities. We have developed a novel tissue culture and plant regeneration system that uses maize leaf tissue and thus is independent of zygotic embryos and greenhouse facilities. We report here: (i) a protocol for the efficient induction of regeneration-competent callus from maize leaves in the dark, (ii) a protocol for inducing highly regenerable callus in the light, and (iii) the use of leaf-derived callus for the generation of stably transformed maize plants.     

Assessment of chemical-crosslink-assisted protein structure modeling in CASP13

With the advance of experimental procedures obtaining chemical crosslinking information is becoming a fast and routine practice. Information on crosslinks can greatly enhance the accuracy of protein structure modeling. Here, we review the current state of the art in modeling protein structures with the assistance of experimentally determined chemical crosslinks within the framework of the 13th meeting of Critical Assessment of Structure Prediction approaches. This largest-to-date blind assessment reveals benefits of using data assistance in difficult to model protein structure prediction cases. However, in a broader context, it also suggests that with the unprecedented advance in accuracy to predict contacts in recent years, experimental crosslinks will be useful only if their specificity and accuracy further improved and they are better integrated into computational workflows.     

Sulfur-nitrogen rings: Relative stabilities and structures

Topological resonance energies (TRE) of some known and proposed sulfur-nitrogen rings and polycycles have been calculated as part of an attempt to understand structural and stability trends in this series of compounds. we have compared our results with those of similar calculations for aromatic hydrocarbons of comparable ring size and of the same number of pi electrons. Planar SN rings have TRE per electron (PE) values that are within the range of those of hydrocarbon annulenes. The TRE(PE) of planar SN rings generally decrease with larger numbers of pi electron as is the case for hydrocarbon annulenes. But unlike the hydrocarbons, which for a given number of pi electron show declining TRE(PE) as the rings get larger, the SN values seem to increase with ring size. some polycyclic SN systems have greater TRE(PE) than do the corresponding monocycles. Our results suggest that the several compounds that have not yet been reported experimentally should be stable.     

Novel nicotinamide analog as inhibitor of nicotinamide N-methyltransferase

Nicotinamide N-methyltransferase (NNMT) has been linked to obesity and diabetes. We have identified a novel nicotinamide (NA) analog, compound 12 that inhibited NNMT enzymatic activity and reduced the formation of 1-methyl-nicotinamide (MNA), the primary metabolite of NA by ～80% at 2?h when dosed in mice orally at 50?mg/kg.     

Interaction of influenza virus proteins with planar lipid bilayers: A model for virion assembly

Changes in conductance of oxidized cholesterol planar lipid bilayers were measured following the incorporation of isolated surface glycoproteins; hemagglutinin and neuraminidase (HA+NA) or matrix protein (M-protein) of influenza virus. The conductance dependence of the lipid bilayers on the HA+NA or M-protein concentrations indicates different mechanisms of interaction of these viral proteins with the lipid bilayer. Adsorption of M-protein molecules on one side of the lipid bilayer affects the character of the HA+NA interaction with the opposite side. Planar lipid bilayers can be a useful model for investigation of the assembly of influenza virions and other enveloped viruses.     

EPR titration of ovine prostaglandin H synthase with hemin

To characterize further the prosthetic group of PGH synthase (EC 1.14.99.1), titrations of the apoenzyme with hemin were investigated by EPR. The first hemin bound per polypeptide showed an EPR signal at g = 6.7 and 5.3 (rhombicity 9%) and was tentatively assigned to the hemin effective as prosthetic group of PGH synthase. Additional hemin bound showed a less rhombic signal (g = 6.3 and 5.8, rhombicity 3%) presumably due to nonspecific hydrophobic binding sites not effective in catalysis.