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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Desenvolvimento de bibliotecas baseadas em serpinas para geração de inibidores de calicreínas teciduais humanas

Souza, Lucas Rodrigo de January 2017 (has links)
Orientador: Prof. Dr. Luciano Puzer / Tese (doutorado) - Universidade Federal do ABC, Programa de Pós-Graduação em Biossistemas, 2017. / As calicreinas teciduais humanas (KLKs) compreendem uma familia de quinze serino proteases encontradas em uma diversidade de fluidos e tecidos biologicos. Estas enzimas sao identificadas como possuindo papel em diferentes doencas como Alzheimer, cancer, dermatite atopica, esclerose multipla, Parkinson, psoriase e outras. Existe, portanto, uma crescente demanda por inibidores especificos para cada uma das calicreinas e este e o objetivo do nosso grupo de pesquisa na UFABC. Neste trabalho pretendemos gerar inibidores para as calicreinas teciduais humanas 3, 5 e 7, utilizando bibliotecas baseadas em duas serpinas diferentes: uma expressando a forma Pittsburgh do inibidor de proteinase-¿¿1 (IP-¿¿1 M358R), randomizada nos residuos 352-356 (P7-P3); e outra expressando a serpina bacteriana vioserpina, randomizada nos residuos 343-347 (P3-P2f). A abordagem do phage display foi eficaz para gerar as bibliotecas e o protocolo de bioselecao utilizado adequado para enriquecer diversas variantes reativas. Na selecao da biblioteca do IP-¿¿1 M358R, consensos PSEAL e PSRIL foram observados, para KLK5 e KLK7, respectivamente, e varias das sequencias selecionadas exibiram maiores taxas de inibicao para ambas as calicreinas, quando comparadas a molecula molde (IP-¿¿1 M358R). A variante HDVIL e o consenso PSRIL foram identificados como sendo altamente seletivos para a KLK7, com constantes de segunda ordem 14 e 33 vezes maiores que as para KLK5. Pudemos realizar uma selecao efetiva da biblioteca de vioserpina contra a KLK7, cujas variantes enriquecidos demonstraram uma preferencia geral pelo aminoacido Serina ocupando as posicoes P3, P1f, P2f e P1, seguido por uma Tirosina, tambem preferida em P2. A tecnica de phage display foi, portanto, eficiente como base para um estudo de especificidade, e para o desenvolvimento de melhores e mais especificos inibidores para as Calicreinas Teciduais Humanas, e pode ser utilizada para o desenvolvimento de novas bibliotecas, com outras regioes da RCL randomizadas, ou mesmo baseadas em outras serpinas. / The human tissue kallikreins (KLKs) comprise a family of fifteen serine proteases found in a diversity of biological fluids and tissues. These enzymes are identified as having a role in different diseases such as Alzheimer's, cancer, atopic dermatitis, multiple sclerosis, Parkinson's, psoriasis, and others. Thus there is a growing demand for specific inhibitors for each of these kallikreins, and this is the aim of our group at UFABC. In this work we intended to generate inhibitors for the human tissue kallikreins 3, 5 and 7, using libraries based on two different serpins: one expressing the Pittsburgh form of the human serpin á1-proteinase inhibitor (á1-PI M358R), randomized at residues 352-356 (P7-P3); and another one expressing the bacterial vioserpin, randomized at residues 343-347 (P3-P2¿). The phage display approach was effective to generate the libraries and the biopanning protocol used suitable to enrich numerous reactive variants. On the á1-PI M358R selection, loose consensus of PSEAL and PSRIL were observed, for KLK5 and KLK7, respectively, and several of the selected sequences exhibited higher inhibition rates when compared to the template molecule for both kallikreins. The variant HDVIL and consensus PSRIL were found to be highly selective for the KLK7, with second order constants 14- and 33-fold higher than the ones for KLK5. We could only perform an effective selection with the vioserpin library for the KLK7, whose enriched variants demonstrated a general preference for the amino acid Serine occupying the positions P3, P1¿, P2¿ and P1, followed by a Tyrosine, also preferred on the P2. The phage display approach was therefore effective as basis for a specificity study, and for the development of improved, more specific inhibitors for the Human Tissue Kallikreins, and can be used to develop new libraries, with other randomized RCL regions, or even based on other serpins.
2

Human prostate-specific antigen and glandular kallikrein 2:production and characterization of the recombinant proteins, and association with prostate cancer

Herrala, A. (Annakaisa) 06 September 2002 (has links)
Abstract Human prostate-specific antigen (hPSA, KLK3) and glandular kallikrein 2 (hK2, KLK2), two members of a large human tissue kallikrein enzyme family, were produced as recombinant mature proteins for the first time and characterized. Furthermore, their association with prostate cancer was studied. Both proteins were produced with baculovirus expression vector system in pilot-scale using bioreactors. Recombinant hPSA was either active with chymotrypsin-like activity or inactive with incorrect processing of N-terminus. The molecular weight of active recombinant hPSA was 31 kD and it formed stable complexes with serine protease inhibitors, α1-antichymotrypsin (ACT) and α2-macroglobulin (2αM). Two polymorphic forms of KLK2, Arg226hK2 and Trp226hK2, were found. The recombinant Arg226hK2 had trypsin-like activity, while recombinant Trp226hK2 was inactive. The Arg226hK2 was labile with low production yields. The molecular weights of hK2 polymorphic forms were 33 kD. hPSA isoforms secreted by prostate cancer cells, LNCaP, were isolated and characterized. These proteins were N-terminally heterogeneous: 10-60% of LNCaP-PSAs were correctly processed. Molecular modeling suggested that the additions or deletions of two or four N-terminal amino acids could affect the three-dimensional structure and reduce the activity of LNCaP-PSA. Active isoforms had chymotrypsin-like activity and formed stable complexes with ACT and 2αM. The expression of hPSA and hK2 was studied with in situ hybridization and immunohistochemistry techniques in benign and cancerous prostate tissue. hK2 mRNA was expressed at a significantly higher level in prostate cancer tissue than in benign prostate tissue (P < 0.0005). The hPSA mRNA expression levels were reversed (P = 0.06). In benign tissue, the mean level of hK2 mRNA was 82% of the respective value of hPSA (P < 0.003), whereas in tumor tissue the mean hK2 expression level was 21% higher than that of hPSA (P < 0.01). The results at protein level supported the mRNA findings. There was a correlation between hPSA and hK2 mRNA levels in both benign (r = 0.735; P < 0.01) and malignant (r = 0.767; P < 0.01) prostate tissue. It was shown with competitively differential PCR that the KLK2 gene was amplified in prostate tumor tissue, while the KLK3 gene was not. These results suggest that hK2 and hPSA have a diverse value in the diagnosis of prostate cancer.
3

Planejamento e síntese de peptideomiméticos como candidatos a inibidores de calicreínas teciduais humanas 5 e 7

Azevedo, Pedro Henrique Rodrigues de Alencar 12 March 2018 (has links)
Submitted by Biblioteca da Faculdade de Farmácia (bff@ndc.uff.br) on 2018-03-12T17:36:57Z No. of bitstreams: 1 PEDRO HENRIQUE RODRIGUES DE ALENCAR AZEVEDO.pdf: 15048741 bytes, checksum: a121d29e5dc4898c7b8e4a85def01e12 (MD5) / Made available in DSpace on 2018-03-12T17:36:57Z (GMT). No. of bitstreams: 1 PEDRO HENRIQUE RODRIGUES DE ALENCAR AZEVEDO.pdf: 15048741 bytes, checksum: a121d29e5dc4898c7b8e4a85def01e12 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / As calicreínas teciduais humanas (KLKs) compreendem uma família de 15 enzimas serina proteases (KLKs 1-15) amplamente encontradas nos tecidos humanos. Em diversas patologias como a dermatite atópica, psoríase, síndrome de Netherton, câncer de ovário, mama e testículos, as KLKs encontram-se em concentrações elevadas. Por exemplo, as KLKs 5 e 7 estão mais abundantemente expressadas na pele, na qual estão envolvidas com o processo de descamação da mesma, e também presentes em alguns tipos de carcinomas. Dessa forma, as KLKs 5 e 7 são consideradas importantes alvos terapêuticos para o tratamento de doenças onde elas encontram-se superexpressadas, enfatizando a existência de somente um fármaco comercialmente disponível como inibidor de KLK. Nesse contexto, o trabalho descreve a síntese de 3 séries de compostos peptideomiméticos, incorporando o cerne estatina e diferentes resíduos de aminoácidos, planejados como candidatos a inibidores das enzimas serina proteases do KLKs 5 e 7. Os compostos finais foram obtidos utilizando uma rota sintética eficiente tendo como reação-chave a formação da ligação peptídica entre o cerne estatina e cloridratos de aminoésteres, previamente sintetizados. Os compostos sintetizados foram identificados por técnicas de Ressonância Magnética Nuclear, Infravermelho e Espectrometria de massas de alta resolução e os produtos finais serão avaliados em testes in vitro de inibição das enzimas KLKs / Human tissue kallikreins (KLKs) comprise a family of 15 serine protease enzymes (KLKs 1-15) widely found in human tissues. In several pathologies such as atopic dermatitis, psoriasis, Netherton syndrome, ovarian, breast and testis cancer, KLKs are in high concentrations. For example, KLKs 5 and 7 are more abundantly expressed in the skin, in which they are involved in the desquamation process, and also present in some types of carcinomas. Thus, KLKs 5 and 7 are considered important therapeutic targets for the treatment of diseases where they are over expressed, emphasizing the existence of only one commercially available drug as a KLK inhibitor. In this context, the work describes the synthesis of three series of peptideomimetic compounds incorporating the statin core and different amino acid residues, designed as candidates for inhibitors of the serine protease enzymes of KLKs 5 and 7. The final compounds were obtained using an efficient synthetic route based on the reaction of formation of the peptide bond between the statin core and previously synthesized amino acid hydrochlorides. The synthesized compounds were identified by Nuclear Magnetic Resonance, Infrared and High Resolution Mass Spectrometry techniques and the final products will be evaluated in in vitro inhibition assays of the KLKs enzymes

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