PEPTIDES

Author: RUIZ NORTES CRISTINA.
Year: 2004.
University: MURCIA [www.um.es].
Place of defense: FACULTAD DE MEDICINA.
Place of preparation: FACULTAD DE MEDICINA UNIVERSIDAD DE MURCIA.

Summary: The peptide TRH-Like pGlu-Glu-Pro-amida a tripéptido related releasing hormone triortropina, is present in the semen and human activity has a powerful stimulating the training of sperm. To find the molecular origin of this peptide, which investigated the presence of the same and the peptides associated with HRT in human prostate, prostatic secretions and seminal fluid. The peptides were isolated and Chromatographic purification using different stages of sequentially (gel exclusion chromatography, ion exchange chromatographies and high performance liquid chromatography), which found his presence and concentration, using a radioimmunoassay (RIA) with a antibody against HRT. The prostates of four patients who had benign prostatic hyperplasia (BPH) and that of a patient who did not present any condition, characterized by having very low concentrations of peptides with inmunorreactividad to HRT, including the tripéptido pGlu-Glu- Pro-amida. These levels did not justify the high levels of tripéptido that we determine in prostatic secretions and semen, but the prostate tissue showed high concentrations of low molecular weight peptide related to this tripéptido, which was detected with a pre-heat treatment RIA. This new molecular form, not mentioned above, and which we called "peptide I" presents a core group and a concentration 100 times greater, as a minimum, that the tripéptido in human prostate, so it should be the main peptide HRT linked to the same. The results show that the levels of pGlu-Glu-Pro-amida are insignificant in human prostate, but it seems to be present in the form of a precursor, the peptide I, by which it is suggested that the tripéptido is released from the same outside the glángula prostate. By studying the mechanism of formation of the isolated forms in the prostate was discovered the presence of longer forms of peptide I at the same; possibly, these forms are acting as their parent molecule, its prohormona. These forms are longer mold sN-ectendidas of Peptide I are susceptible to both the hydrolysis of prostate-specific antigen (PSA) as to their enzymatic activities, trypsin and chymotrypsin, independently. Moreover, these forms had higher levels than in normal prostates prostates with benign hyperplasia, and this result is consistent with what is happening at fisioipatológico that PSA levels are higher in prostates with this disease. Finally, we proposed a mechanism for regulating new forms molecular discovered in the prostate that suggests a new physiological role for the PSA. This protease is responsible for the processing of prohorma of Peptide I, and therefore could be the enzyme regulating the production of peptides prostatic important for male fertility (fertility promoting peptides).

Author: VÁZQUEZ RODRÍGUEZ JESÚS.
Year: 2004.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: FACULTAD DE QUÍMICA.

Summary: The caspases are a family of cysteine proteases with specificity aspartic acid residues (Asp), which are involved in apoptosis, which serve as amplifying the signal cell death, and processes type imflamatorio. There has been identified so far eleven members of this family of proteases in humans, and they have similarities in terms of the structure, sequence of waste by its substrate specificity. His involvement in cell death is critical and varied: inactivating proteins that protect cells from apoptosis, disruption of structures or derregulación of cellular proteins. They are therefore an attractive target as a therapeutic target. Oe all caspases is caspase-3 family members with greater importance in terms of their involvement in apoptosis and caspase is classified as an executor. Therefore, modulation of its activity at first serve to modulate the signal cell death or apoptosis. The main objective of this thesis was the synthesis of a new type of protease inhibitors is based on the ring hidantoína as "scaffold." That overall goal was divided into a number of sub. First developed the synthetic conditions suitable for the formation of aldehyde and ketone of Fmoc-Asp (O'Su) OH. This was achieved from tioéster of 2-mercaptopiridina corresponding which was subsequently react with several dialquilcupratos to make room for ketones corresponding with good yields. It is also synthesized a-halometilcetonas, by reaction with diazomethane, and the aldehyde corresponding reduction corresponding to alcohol and his subsequent oxidation to aldehyde. Once obtained compounds carbonílicos also investigated how anclarlos a solid support. It was tested with resin type Wang and the chloride 2-clorotritilo (CTC) to anchor derivatives Asp by his side chain-type resins and hydrazine, semicarbazona and semicarbazida for anclarlos by the carbonyl group through the formation of a imina . The latter was the one that offered better results when using a resin semicarbazida derived from a commercial resin aminomethane. It also investigated the conditions of synthesis of hydantoins in solid phase. Two conditions were obtained for the synthetic hydantoins. One was obtained hydantoins with epimerización center estereogénico immediately preceding the ring hidantoína. The method passed by the introduction of carbonyl activated through CSOs (10 equiv.) In the presence of OMAP (1 equiv.) Followed by two basic treatments with K2COSy a distinction O 4Mde 18-c-6 in OMF. It also obtained a synthesis method that allowed the taking of hydantoins db form epiméricamente pure. In this case the introduction of carbonyl was activated by IOC (5 equiv.) Followed by two basic treatments with OIEAen OMF (1:4). Once the conditions synthetic derivatives carbonílicos and ring hidantoína were synthesized compounds successive families helped by the results offered bioassay further study molecular dynamics. We synthesized a total of 8 generations of compounds that were planned according to the results offered. The first generation consisted of hydantoins that were directly linked to Asp residue and was formed by OAPA that was acilado in its side chain with composite heteroaromáticos. The second generation was introducing a new waste between the ring hidantoína and Asp residue. The hydantoins were: synthesized with different amino acid side chain with its functional hoisted. The third generation was conducted with Abu as a residue between the ring G hidantoína and Asp and hydantoins were formed with the Arg taking the group guanidinio funcionalizado in various ways: tetrasust 8 ituido 1 2cd) protected sulfonilos aromatic. In addition to the trials of racing in front of caspase-3 were tested for metabolic stability compared to human serum and showed great stability. Tests were also conducted on the feasibility of those who were able to deduce that these compounds are not toxic.

Author: TEIXIDÓ TURÁ MERITXELL.
Year: 2005.
University: BARCELONA [www.ub.es].
Place of defense: FACULTAD DE QUÍMICA.
Place of preparation: UNIVERSIDAD DE BARCELONA, FACULTAD DE QUÍMICA.

Summary: The main aim of the thesis focuses on knowledge of the properties fiscoquímicas qu make it possible that a peptide is able to cross the blood-brain barrier. This objective can realize in a seríe stages: Designing a genetic algorithm that enables relational physicochemical properties with the ability to cross the barrier hematoencefálicas. Design and comparative analysis of different trials (chromatographic of partition between phases, in vitro cellular ..) that account for the permeability of a peptide compared to the blood-brain barrier. Summaries of a first generation of peptides proposed by the generic algorithm. Evaluation of this first generation of peptides and the study of compounds with a better transportation. The results of this thesis can be drawn the following conclusions: The approach to the design of peptides that combines the genetic algorithm, the synthesis of peptides in solid phase i assessment by CHCIs has demonstrated its usefulness to deepen the study of capacity peptide molecules to cross the barrier hematoencéfalica. Among the peptides of the first generation emphasizes the peptide 3, transported by passive diffusion from that structure has been studied by dicroismo move and resonáncia nuclear magnetic showing some interesting properties of aggregation. The peptide 22 has also shown interesting properties of transport, being able nature of dipol play an important role. The synthesis of the first generation has been a major challenge due to alevado content synthesis of N-methyl amino acids present. A séroe reactions secundárias have been identified and avoided as far as possible: deletion products and sobreincorporación during the elongation of the peptide chain reactions of fragmentation and training DKPs during treatment acidolítico division and unprotected, as well as a chromatographic high complexity of the amino acid N-methyl-rich peptides. The comparative analysis of different techniques for prediction of transport through the barrier hematencefálica has made us decant by chromatography membrane artificial immobilizada (CHCIs) as a technique for making ránquings assessment of the ability of peptides to cross the blood-brain barrier by passive dissemination. The algorithm based on data from CHCIs to the first generation of 24 peptides has developed a second generation, the study of which is expected improvement in the ability to cross the blood-brain barrier. The permeability in the trial PAMPA és a more demanding than CHCIs. The use of this technique should be reserved for the more advanced analysis of populations.