BIOSYNTHESIS

Author: MARTINEZ RODRIGUEZ SERGIO.
Year: 2004.
University: ALMERÍA [www.ual.es].
Place of defense: FACULTAD DE CIENCIAS EXPERIMENTALES.
Place of preparation: FACULTAD DE CIENCIAS EXPERIMENTALES. UNIVERSIDAD DE ALMERIA.

Summary: The motivation for the investigation of processes and methods biocatalíticos is increasingly marked by the interest in the synthesis of compounds enantioméricamente cigars (CEPs). The specific activity of CEPs usually depends on its quiralidad. Only one of the isomers is useful for an end determínado, while the other is considered pollution. The CEPs required by the industries can be synthesized químícamente. However, most of the compounds obtained by organic synthesis are mixtures racémicas to be resolved until its components optically pure before being used. The resolution of these compounds can be made by chemical and / or biological agents, which include cristalizacíón salt estereoméricas, crystallization solvent optically active chromatography and / or enzymatic methods. All these procedures have very limited industrial application because of its low yield, low profitability and strong polluting effect of the environment. The optically pure amino acids have a great industrial importance because of their potential for use in a variety of fields, including pharmaceuticals and food, as well as microbiological and biochemical investigations. It has described its use in the manufacture of sera, as a food additive, or as intermediate in the preparation of drugs, cosmetics, pesticides, synthetic leather and implementation of chiral reagents in organic synthesis. The L-aminoácidos natural or proteinogénicos, can be obtained by the fermentation of natural microbial strains or mutants. However, other methods are needed for the production of L-aminoácidos unnatural and D-aminoácidos. There are various methods of chemical synthesis of a-aminoácidos. The interesting from the point of view are those that use industrial compounds low cost, all these processes limited to two methods of synthesis: a) Synthesis of Strecker b) of a-cetoácidos ami nation reductive. Both methods result in a racemic mixture that needs to be resolved before used. This step purification limits its industrial application, due to high cost and low redeeming. The restrictions imposed by traditional chemical synthesis led to the search for other methods that would allow the direct taking of optically pure aas files. The production of amino acids L Do optically pure through enzymatic catalysts made from blends racémicas D, L-hidantoinas monosustituidas in carbon 5 is a cheaper and technically simpler than the methods of chemical synthesis and quimioenzimática, besides being cleaner . This process is sometimes called the "process of hidantoina." This enzymatic transformation in the first place, the ring of hidantoinas D L-5-sustituidas synthesized chemically is hydrolyzed by the enzyme hidantoinasa. Subsequently, the hydrolysis of N-carbamil amino acid produced is done by the enzyme N-carbamil-aminoácido amidohidrolasa (carbamilasa). This reaction occurs NH3, CO2 and the corresponding amino acid. At the same time the hidantoinasa hydrolyzed specifically an isomer or another of the hidantoina begins racemisation chemical or enzymatic the other isomer not hydrolyzed. The production of an enantiomer or another of aminoácído depends on the estereoespecificidad of enzymes with which it works. The chemistry of racemisation hydantoins is in a position strongly alkaline by tautomerismo ceto-enólico, and its speed depends on the electronegatividad of replacement carbon 5. Racemisation times are very high, which limits the acquisition of a 100% of D-aminoácido optically pure to a very small number of hydantoins. Only speed racemizacíón 8 espontá 69c line of parahidroxifenilhidantoína and fenilhidantoína ago profitable industrial obtaining their corresponding D-aminoácidos. Therefore, the vast majority of D L-hidantoínas replaced not racemizan spontaneously to an appropriate speed, and lengthening encareciendo obtaining amino acids from them. The speed of racemisation of hidantoinas can be increased to make profitable use of the catalytic action of the enzyme hidantoín racemasa. The joint use of this enzyme, D-hidantoinasa and D-carbamilasa allows the total transformation of the hidantoina in D-aminoácido. Evídenciada tremendous improvement in the process of hidantoina following incorporation of the third enzyme, in our laboratory are raising the search for this enzyme in natural sources, and construction of a recombinant multienzimático for conversion total hydantoins racémicas until D-aas optically pure.

Author: REINA PINTO JOSÉ JUAN.
Year: 2004.
University: MÁLAGA [www.uma.es].
Place of defense: FACULTAD DE CIENCIAS.
Place of preparation: FACULTAD DE CIENCIAS.

Summary: The upper floors have a cover nature lipid lining the aerial parts of the same and that isolates the external environment surrounding. This coverage is called plant cuticle and primarily consists of a biopolímero hydroxy acids acids of 16 or 18 carbon atoms. This polymer is called cutina. In this dissertation work has been carried out a study of a specific protein in the skin of young leaves of the plant Agave americana L. The cloning of cDNA derived from the mRNA that encodes a protein AgaGDSL showed that the protein belongs to the family of lipases type II or lipases GDSL. The expression of mRNA that is unique to the area basal young leaves of the plant (30-35 cm). Experiments inmunocitolocalización showed that AgaGDSL is located in the epidermal layer of cells immediately below the plant cuticle and also its location in the most active areas of growth on the leaf of correlated positively with the increase of components cuticulares (cutina, waxes and cután) in such areas. The expression of this protein in a heterologous in E.coli did not give the protein in its active form after several experiments induction.

Author: Sevilla Camins Angel.
Year: 2005.
University: MURCIA [www.um.es].
Place of defense: Facultad de Química.
Place of preparation: Facultad de Química.

Summary: This memory has conducted a comprehensive study that combines metabolic levels, genomic, and señalómicos the biotransformation of the compounds trimetilamonio L - (-) -carnitina by E.coli, to optimize the synthesis of carnitine through analysis the experimental results obtained and the development of detailed mathematical models. The first attempt made in order to optimize the biotransformation of carnitine has been a simple model of the overall process (Cánovas et al., 2002). In this model it has added the ability to simulate and predict the evolution of metabolic pathways that were involved in the biotransformation. After it has combined the central and metabolism carnitine levels of ATP and coenzymes CoA, taking into consideration the approach of analysis Metabolic Flows (MFA). In addition, it has conducted a pilot study in order to validate the findings obtained in the previous models by the disruption of bioproceso with the main products of fermentation and biotransformation of the substrate. In addition, we have modeled and validated signaling pathways and gene expression of the components of metabolism carnitine, including transcription, translation and processes degradativos, and using the approximation hierarchical Kremling and Gilles (2001). The results obtained in these studies have identified checkpoints in the biotransformation of carnitine both macroscopic (reactor) as a microcosmic level (intracellular). Not only has determined that the process is dependent on the ATP biotransformation, but also the cellular redox state is also a very important factor for its optimization. Moreover, it has established the mechanism of inhibition by glucose metabolism carnitine and one way to avoid it. It has also found an indicator of the state of bioproceso (cAMP) where glucose is used as a source of carbon.

Author: CASTELAN FRANCISCO.
Year: 2006.
University: MIGUEL HERNÁNDEZ DE ELCHE [www.umh.es].
Place of defense: INSTITUTO DE NEUROCIENCIAS, UMH,CSIC.
Place of preparation: INSTITUTO DE NEUROCIENCIAS.

Summary: The aim of the thesis is to contribute to knowledge of the molecular mechanisms that influence the expression of neuronal nicotinic receptors. The immediate objectives were: 1) To determine the influence of domains citoplásmaticos specific type of nicotinic receptor alpha 7 in its functional expression. To that end, a survey was conducted of mutagenesis with the amino acid Ala monitorizándose the surface receptor expression and functional activity. The results indicate a key role in a region anfipática close to segment M4 in the biogenesis and function of the receptor. 2) characterize the effects of CIP-3 on the modulation of neuronal nicotinic receptors. It analyzes the effect of this protein in the biogenesis and transport surface receptor. Likewise, identified domains protéicos involved in the modulation of both parameters. The results suggest a key role of the protein RIC- 3 in the biological activity of nicotinic receptor alpha 7.