1,149 research outputs found
Ceppo batterico per la degradazione di miscele di idrocarburi aromatici mono e policiclici
No full textIl brevetto concerne un nuovo ceppo batterico, Novosphingobium puteolanum PP1Y (DSM 19530), isolato da campioni di acqua marina superficiale raccolti nel porto di Pozzuoli (NA) capace di degradare idrocarburi aromatici mono- e policiclici e sintetizzare molecole con proprietà surfattanti e gelatinizzanti. Il ceppo ha dimostrato la capacità di utilizzare come uniche fonti di carbonio ed energia numerosi composti aromatici mono- e poli-ciclici forniti in forma pura o disciolti in oli quali paraffine e oli siliconici. Inoltre il ceppo PP1Y è in grado di utilizzare come uniche fonti di carbonio ed energia benzina, kerosene e gasolio per motori a scoppio. Il ceppo produce materiale extracellulare con attività gelatinizzante e surfattante che determina l’emulsione di fasi oleose in sistemi bifasici acqua/olio. Le attività metaboliche di questo ceppo possono essere utilizzate per la biodegradazione di miscele complesse di composti aromatici mono e policiclici eventualmente disciolte in fasi oleose. Il ceppo può essere inoltre utilizzato come fonte di molecole con proprietà surfattanti e/o gelatinizzanti e di catalizzatori enzimatici per la biosintesi di composti ad elevato valore aggiunto
Bacterial strain for the degradation of mixtures of mono- and poly-cyclic aromatic hydrocarbons dissolved in oil phases
No full textThe invention relates to a new bacterial strain, Novosphingobium puteolanum PP1Y (DSM 19530), isolated from seawater samples collected at the sea surface inside the harbour of Pozzuoli (NA). This tsrain shows the ability to use as the sole carbon and energy source several mono- and poly-cyclic aromatic hydrocarbons both in pure form and dissolved in oils as paraffin oils and silicone oils. Moreover the strain PP1Y is able to use as the sole source of carbon and energy the aromatic fractions of several fuel oils as gasoline, kerosene and disel oil. The strain produces extracellular material, prevalently composed by proteins, with emulsifying and gelatinizing activity which stabilizes the emulsion of the oil phase in water/oil biphasic systems. The metabolic abilities of this strain could be used for the bioremediation of complex mixtures of mono- and poly-cyclic aromatic hydrocarbons even when dissolved in oil phases.
Moreover the strain could be used as source of molecules with emulsifying and gelatinizing activity and of enzymatic catalyst for the biosynthesis of compounds with high added valu
Enthalpic and entropic consequences of the removal of disulfide bridges in ribonuclease A.
No full text
Enthalpic and entropic consequences of the removal of disulfide bridges in ribonuclease A.
No full textNew clues into the self-assembly of Vmh2, a basidiomycota class i hydrophobin
No full textHydrophobins are fungal proteins that can selfassemble into amphiphilic films at hydrophobic-hydrophilic interfaces. Class I hydrophobin aggregates resemble amyloid fibrils, sharing some features with them. Here,
five site-directed mutants of Vmh2, a member of basidiomycota class I hydrophobins, were designed and characterized to elucidate the molecular determinants playing a key role in class I hydrophobin self-assembly. The mechanism of fibril formation proposed for Vmh2 foresees that the triggering event is the destabilization of a specific loop (L1), leading to the formation of a β-hairpin, which in turn generates the β-spine of the amyloid fibril
MUTATION OF GLUTAMIC-103 OF TOLUENE O-XYLENE MONOXYGENASE AS A CONTROL OF THE CATABOLIC EFFICIENCY OF A RECOMBINANT UPPER PATHWAY FOR THE DEGRADATION OF METHYLATED AROMATIC COMPOUNDS
No full textToluene o-xylene monooxygenase (ToMO) and phenol hydroxylase (PH) of Pseudomonas stutzeri OX1 act sequentially in a recombinant upper pathway for the degradation of aromatic hydrocarbons. The catalytic efficiency and regioselectivity of these enzymes optimize the degradation of growth substrates like toluene and o-xylene. For example, the sequential monooxygenation of o-xylene by ToMO and PH leads to almost exclusive production of 3,4-dimethylcatechol (3,4-DMC), the only isomer that can be further metabolized by the P. stutzeri meta pathway. We investigated the possibility of producing ToMO mutants with modified regioselectivity compared with the regioselectivity of the wild-type protein in order to alter the ability of the recombinant upper pathway to produce methylcatechol isomers from toluene and to produce 3,4-DMC from o-xylene. The combination of mutant (E103G)-ToMO and PH increased the production of 4-methylcatechol from toluene and increased the formation of 3,4-DMC from o-xylene. These data strongly support the idea that the products and efficiency of the metabolic pathway can be controlled not only through mutations that increase the catalytic efficiency of the enzymes involved but also through tuning the substrate specificity and regioselectivity of the enzymes. These findings are crucial for the development of future metabolic engineering strategies
Cryptic antimicrobial peptides: Identification methods and current knowledge of their immunomodulatory properties
No full textCationic antimicrobial peptides (CAMPs), also known as host defence peptides (HDPs), are essential evolutionarily conserved components of innate immunity, constitutively or inducibly expressed in response to invasion by pathogens. In addition to a direct antimicrobial action, they are able to synergistically operate with other defence molecules to combat infection by neutralization of endotoxins, chemokine-like activities, induction of angiogenesis and wound repair. The importance of CAMPs has been highlighted in animal models and supported by observations in patient studies. CAMPs are attractive alternative candidates to antibiotic treatment, because they offer several advantages over the currently used drugs, moreover, knowledge on these peptides, especially regarding the intertwinement between their structure, function and mechanism of action, could be applied in the rational design of antimicrobial/anti-inflammatory/wound healing enhancing drugs. CAMPs combat pathogens by targeting bacterial membranes and essential membrane-related functions, and, in some cases, also target intracellular components. Despite differences in their size and sequence, many of them share a net positive charge and fold into amphipathic structures after contact with bacterial surfaces or endotoxins like lipopolysaccharides and lipoteichoic acid. Due to their peculiar mechanism, acquisition of resistance towards these peptides would be difficult for the bacteria. Very interestingly it has been demonstrated that several proteins, including proteins apparently not involved in immunity, can behave as sources of CAMPs hidden in their primary structures and released by the action of host and/or bacterial proteases. The existence of these "cryptic CAMPs" suggests that the panel of antimicrobial peptides present in higher eukaryotes and the variety of functions they perform could be much wider and more complex than previously suspected. This review focuses on source, structure and mechanism of action of cryptic CAMPs, with special attention to their immunomodulatory functions
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