As an axon grows, the growth cone at its advancing edge encounters specific ‘choice points’ at which guidance cues steer specific axons towards their appropriate destinations. Such cues may attract a subset of axons towards a given domain, repel axons from inappropriate target regions or simply provide a permissive substrate for axonal outgrowth. There are many different ways in which a guidance signal might intervene to steer the growth cone. For example, a guidance cue might promote the initiation, extension, stabilization, or retraction of individual filopodia, or the capture or stabilization of microtubules in specific regions of the growth cone. In each of these cases, guidance signals must be relayed through the growth cone to the actin cytoskeleton,[..]

Cyanide is an important industrial chemical produced on a grand scale each year. Under physiological conditions at pH 7, Cyanide is mostly present as HCN (Hydrogen Cyanide). HCN, being volatile and less dense than air, can rapidly diffuse into the environment. Although extremely toxic to mammalian life, Cyanide is a natural product generated during Cyanogenesis by fungi, algae, plants and bacteria. These organisms degrade Cyanide either to detoxify it, or to use it as a source of nitrogen for growth. Cyanogenesis in a wide range of plants constitutes a chemical defense against herbivores and pathogens. Plants use Cyanogenic Glucosides (e.g. Amygdalin) as precursors of Cyanide. Cyanide detoxification mechanisms are widespread in nature and involve enzymatic degradation[..]

Leptospira is a genus of spirochaete Gram negative bacteria, which is divided into 20 species. Leptospira are obligate aerobe spirochete with cytoplasmic and outer membrane and two flagella that extend from the cytoplasmic membrane at the ends of the bacterium into the periplasmic space and are necessary for the motility of Leptospira. Leptospira interrogans are also grouped into serovars according to their antigenic relatedness. There are currently over 200 recognized serovars. L. interrogans infects wild and domestic animals, including pet dogs. Humans are accidental hosts. L. interrogans is usually transmitted to humans through contact with infected animal urine, either directly or in water. It invades directly through broken skin and can replicate in the liver and[..]

Idiomarina loihiensis is a deep-sea Gamma-proteobacterium. The bacterial genome encodes diverse peptidases, a variety of peptide and amino acid uptake systems, and versatile signal transduction machinery. In contrast to obligate anaerobic vent hyperthermophiles, I. loihiensis inhabits partially oxygenated cold waters at the periphery of the vent, surviving a wide range of growth temperatures (from 4°C to 46°C) and salinities (from 0.5% to 20% NaCl). The source of amino acids for I. loihiensis growth is the proteinaceous particles, present in the deep sea hydrothermal vent waters. The microbe is an opportunistic colonizer of proteinaceous particles in the deep-sea hydrothermal vent waters and colonizes these particles by using the secreted exopolysaccharide,[..]

Gloeobacter is a genus of cyanobacteria. Gloeobacter violaceus (G. violaceus) the unicellular cyanobacterium is the only known oxygenic photoautotroph which does not contain thylakoid membranes hence all membrane-bound bioenergetic processes take place in the green plasma membrane of this organism. G. violaceus is a rod-shaped, unicellular cyanobacterium with unusual characteristics. It is an obligate photoautotroph, sensitive to strong light and it has a relatively long generation time (Ref.1). Cyanobacterias are the organisms to be exposed to the toxic reactive oxygen species (ROS): singlet oxygen (1 O2), superoxide anion (O2−), hydrogen peroxide (H2O2), and hydroxyl radical (OH) as they have evolved from oxygenic photosynthesis. ROS is generated when[..]

Xanthomonas is a Gram-negative rod-shaped bacterium known for being a common plant pathogen. Xanthomonas campestris causes black rot, which affects crucifers such as Brassica and Arabidopsis. Symptoms include marginal leaf chlorosis and darkening of vascular tissue, accompanied by extensive wilting and necrosis. This bacterium is grown commercially to produce the exopolysaccharide xanthan gum, which is used to control viscosity and as a stabilizing agent in many industries. Xanthomonas affects many types of hosts, including citrus, beans, grapes, cotton, and rice. Typical symptoms of the disease include lesions on the leaves, fruit, and stems as well as twig dieback (Ref.1).Glutathione metabolism in Xanthomonas occurs within cells in two closely linked, enzymatically[..]

NO (Nitric Oxide) is a short-lived free radical gas involved in diverse physiological and pathological processes. It is produced along with L-Citrulline by the oxidation of L-Arginine and catalyzed by three different isoforms of NOS (NO Synthase). Type-I nNOS (neuronal NOS) and Type-III eNOS (endothelial NOS) are constitutively expressed as latent enzymes and require a higher concentration of Ca2+ for the enzyme activity. In contrast, Type-II iNOS (inducible NOS) is Ca2+ independent because it’s high affinity for Ca2+/Calm (Calmodulin) renders the enzyme active even at basal levels of intracellular Ca2+ . The catalysis of this reaction requires a number of essential cofactors such as mononucleotide, FAD (Flavin Adenine Dinucleotide), and NADPH (Nicotinamide Adenine[..]

Glutathione is a sulfhydryl (-SH) antioxidant, antitoxin, and enzyme cofactor. It is ubiquitous in animals, plants, and microorganisms, and being water soluble is found mainly in the cell cytosol and other aqueous phases of the living system. Glutathione is a tripeptide composed of Glutamate, Cysteine and Glycine that has numerous important functions within cells. It is homeostatically controlled, both inside the cell and outside and often attains millimolar levels inside cells, which makes it one of the most highly concentrated intracellular antioxidants. Glutathione exists in two forms. The antioxidant "reduced Glutathione" tripeptide is conventionally called Glutathione and abbreviated Gsh; the oxidized form is a sulfur-sulfur linked compound, known as[..]

Glutathione is a sulfhydryl (-SH) antioxidant, antitoxin, and enzyme cofactor. It is ubiquitous in animals, plants, and microorganisms, and being water soluble is found mainly in the cell cytosol and other aqueous phases of the living system. Glutathione is a tripeptide composed of Glutamate, Cysteine and Glycine that has numerous important functions within cells. It is homeostatically controlled, both inside the cell and outside and often attains millimolar levels inside cells, which makes it one of the most highly concentrated intracellular antioxidants. Glutathione exists in two forms. The antioxidant "reduced Glutathione" tripeptide is conventionally called Glutathione and abbreviated Gsh; the oxidized form is a sulfur-sulfur linked compound, known as[..]

Pectobacterium carotovorum is a bacterium of the family Pectobacteriaceae. It used to be a member of the genus Erwinia. The bacterium is also known as Erwinia carotovora It is a ubiquitous plant pathogen with a wide host range and is able to cause disease in almost any plant tissue it invades. P. carotovorum is a very economically important pathogen in terms of post-harvest losses, and a common cause of decay in stored fruits and vegetables. Decay caused by P. carotovora is often referred to as "bacterial soft rot" (Ref.1).  At present there are four described subspecies of P. carotovorum: P. carotovorum, P. brasiliense, P. odoriferum, and P. actinidiae. The symptoms caused by Pectobacterium infection include soft rot and wilts resulting from vascular[..]

Microorganisms have developed several mechanisms to survive in their hosts' environments. These include competition with their hosts for metal acquisition and resistance to host defenses such as NO (Nitric Oxide), a cytotoxic weapon generated by macrophages. In eukaryotic cells, NO is metabolically produced by NOS (NO Synthase) from L-Arginine, O2 (Molecular Oxygen), and NADPH (Nicotinamide Adenine Dinucleotide, Reduced). In macrophages, an inducible NO synthase (iNOS or NOS2) is produced after activation by endotoxins or cytokines and generates copious amounts of NO presumably to help kill or inhibit the growth of invading microorganisms or neoplastic tissue. Although iNOS was originally identified and characterized in macrophages, it is present in numerous cell[..]

Francisella is a genus of pathogenic bacteria. The type species, F. tularensis is a rod-shaped Gram-negative bacterium and is the causative agent of tularemia or rabbit fever. The bacterium is an aerobic pleiomorphic coccobacillus, which requires oxygen for growth, is variable in shape, with basic shape between a rod and a sphere, do not move by their own power, and do not form spores. Glutathione metabolism in F. tularensis occurs within cells in two closely linked, enzymatically controlled reactions that utilize ATP and draw on nonessential amino acids as substrates (Ref.1). Glutathione is a tripeptide, composed of glutamate, cysteine and glycine, and has numerous important functions within the bacterial cell. This tripeptide is specifically a thiol compound, present[..]