The protozoan parasite Trypanosoma congolense is one of the aetiological agents of African animal trypanosomiasis that is transmitted by the tsetse fly. The parasite causes nagana in animals and affects livestock throughout sub-Saharan Africa. The toxicity of available drugs and the emergence of drug resistant parasites have affected the treatment of trypanosomiasis. Control of the disease has also been difficult due to ineffective vector control and the potential of trypanosomes to express hundreds of antigenetically distinct proteins on their surface. Vaccination against trypanosomiasis has been thought to be a possible control method. Since a vaccine based on variable surface proteins of the parasite is unlikely, research has been directed towards the identification of invariant pathogenic factors of the parasite as potential targets for therapy. Congopain, the major cysteine protease of T. congolense has been implicated in the pathology of the disease. Antibodies against congopain are known to contribute to the mechanisms of natural resistance to trypanosomiasis known as trypanotolerance by neutralising the pathogenic effects of the enzyme. Oligopeptidase B (OpdB), a trypanosomal serine protease has also been associated as a pathogenic factor of the disease. It is released into the host’s circulation by dead or dying parasites and retains its catalytic activity since it is insensitive to host serum inhibitors. In the present study, the catalytic domain of congopain (C2) and the use of alpha-2-macroglobulin (α2M) as an adjuvant were investigated for their potential use in an anti-disease vaccine. α2-Macroglobulin has been used to varying degrees to target different antigens to cells of the immune system and enhance their immunogenicity. A previous study showed that antibodies raised in rabbits against C2 complexed to α2M gave a higher percentage inhibition than antibodies made using C2 mixed with Freund’s adjuvant. In the present study, goats were immunised with C2 complexed with α2M to confirm the enhanced immunogenicity of C2 and the production of anti-C2 antibodies with superior inhibitory properties. Following immunisation, goats were challenged with T. congolense (strain IL 1180) and showed sustained antibody production during the two month infection period. Goat antibodies made using C2 in complex with α2M inhibited the hydrolysis of hide powder azure by C2 by 96%. Maximum inhibition of the hydrolysis of azocasein was observed to be 63% and hydrolysis of Z-Phe-Arg-AMC by C2 was inhibited by 73%. In order to determine the vaccine potential of OpdB, protein was recombinantly expressed as a glutathione-S-transferase fusion protein in the pGEX expression system and purified by glutathione agarose affinity chromatography and molecular exclusion chromatography. Since a small yield of protein necessitated several rounds of expression and extensive purification, OpdB was subsequently expressed as a His-tagged fusion protein in the pET bacterial expression system. Recombinant protein was easily purified using nickel chelate affinity chromatography. Purified OpdB was used with alum for the immmunisation of mice to produce antibodies capable of inhibiting enzyme activity. Following immunisation, mice were challenged with T. congolense (strain IL 1180) and also showed sustained antibody production following two months infection. Since all mice died, the administration of OpdB conferred no protection; however, anti-OpdB mouse antibodies inhibited 86% of OpdB activity against the substrate Z-Arg-Arg-AMC. In addition immunised mice were observed to survive 40% longer than control mice as they had previously been immunised with OpdB and were able to mount a rapid immune response against this pathogenic factor during infection. In general it could be concluded that immunisation of goats with C2 in complex with α2M produced antibodies with superior inhibitory properties. The immunisation of mice with OpdB and alum also produced inhibitory antibodies and previous administration of OpdB enabled mice to mount a rapid immune response against OpdB during infection. Antibody mediated enzyme inhibition demonstrates the potential use of C2 and OpdB as vaccines that may contribute to the development of an effective anti-disease vaccine. / Thesis (M.Sc.)-University of KwaZulu-Natal, Pietermaritzburg, 2008.

Bibliography: leaves 118-130 / v, 130 leaves, [23] leaves of plates : ill ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Biochemistry, 1984

Thesis (Ph. D.)--Ohio State University, 2007. / Title from first page of PDF file. Includes bibliographical references (p. 152-161).

Thesis (Ph. D.)--West Virginia University, 2008. / Title from document title page. Document formatted into pages; contains viii, 173 p. : ill. (some col.). Vita. Includes abstract. Includes bibliographical references.

Thesis (M.Sc.)--University of Alberta, 2010. / A thesis submitted to the Faculty of Graduate Studies and Research in partial fulfillment of the requirements for the degree of Master of Science, Department of Psychiatry. Title from pdf file main screen (viewed on February 14, 2010). Includes bibliographical references.

Thesis (Ph.D.)--University of Western Australia, 2008.

A disintegrin and metalloprotease (ADAM) 17 cleaves and releases membrane-tethered pro-forms of several signalling molecules from the plasma membrane, including the inflammatory cytokine tumour necrosis factor alpha (TNFα) and ligands of the epidermal growth factor receptor (EGFR). Due to the important functions of its substrates, ADAM17 activity has to be tightly controlled, and its misregulation has implications for inflammation and cancer. The multi-pass membrane proteins iRhom1 and iRhom2 are members of the conserved rhomboid-like superfamily and control ADAM17 activity by several mechanisms throughout the secretory pathway. First, iRhoms facilitate trafficking of the catalytically inactive proenzyme form of ADAM17 from the endoplasmic reticulum (ER) to the Golgi apparatus, where the inhibitory pro-domain of ADAM17 is removed. Subsequently, iRhoms exert a different form of control of ADAM17 at the plasma membrane, this time on stimulus-induced ADAM17 activity, its substrate specificity, and its stability. iRhoms ultimately regulate the release of ADAM17 substrates, and are consequently key players in TNFα and EGFR signalling. However, it remains unclear how iRhom function itself is regulated posttranslationally, and whether iRhoms require co-factors to exert their roles as ADAM17 regulators. The goal of my project was to shed light into these questions by identifying new iRhom interaction partners. I developed a mass spectrometry-based screen to identify new binding partners of human iRhoms using co-immunoprecipitation. The top hit of the screen was the poorly characterised FERM domain-containing protein 8 (FRMD8), which binds to both iRhom1 and iRhom2. FRMD8 was found to play a crucial role in the iRhom/ADAM17 pathway because FRMD8 knockdown and knockout in HEK293T cells significantly reduced the levels of mature ADAM17 and the release of ADAM17 substrates. The closely related metalloprotease ADAM10 was not affected by the loss of FRMD8, implying that FRMD8 is not a general regulator of ADAM metalloproteases. Interaction studies revealed that FRMD8 binds to the cytosolic N-terminus of iRhom2 throughout the entire secretory pathway. FRMD8 loss does not affect the ER-to-Golgi trafficking of iRhom2 but plays a role in stabilising iRhom2 at the plasma membrane by preventing the lysosomal degradation of both iRhom2 and mature ADAM17. Using human induced pluripotent stem cell (hiPSC)-derived macrophages, I showed that FRMD8 regulates mature ADAM17 levels and the ADAM17-dependent release of TNFα in human macrophages. Studies in FRMD8 knockout (KO) mice confirmed the reduced mature ADAM17 levels in all mouse tissues tested, further supporting the conclusion that FRMD8 is a novel regulator of the iRhom/ADAM17 pathway with physiological relevance in mammals. Finally, I showed that the interaction of FRMD8 and iRhom, which are both conserved from Drosophila to human, is also conserved. Furthermore, loss of the FRMD8 orthologue in flies, Bili, leads to motility defects and shows similarity to the loss of iRhom in flies. These results suggest that FRMD8 is a novel regulator of iRhom function in mammals and Drosophila.

My work concentrates on feeding behavior of overwintering diapausing and post {--} diapausing bark beetles and developmental treshold. This is done either biochemically by measuring the enzymatic activity in the midgut and by assessing the feeding status from the size and consistence of the food bolus in the gut. Detailed knowledge of feeding behaviour and development treshold may help to predict the overwintering success of local populations with all the consequencies for spring dispersal and reproduction.

The diploma thesis is focused on enzyme hydrolysis of potato protein concentrates and fractionation of obtained peptide fragments. Were used protein concentrate from tubers variety Ornella and protein concentrate obtained by swedish company Lyckeby Starch AB. The enzyme hydrolysis lasted 24 hours and were used the proteolytic enzyme alkalasa and trypsin. In this work were prove possitive effect of enzyme hydrolysis on solubility and antioxidative properties of potato protein isolates. The fractionation of obtained peptide hydrolysated was based on systém FPLC (Fast protein liquid chromatography). The fractions contained of peptide fragments about 1, 350 kDa or fragments of smaller moleculary weight. The antixodative activity of subfractions were determIne by method called DPPH. The highest values (2,2 and 2,6 TEAC g/kg) were accured at the subfractions which were separations from Ornella hydrolyzates digeste by enzyme alkalasa.

Bactérias psicrotróficas foram isoladas de leite cru refrigerado oriundo de duas indústrias de beneficiamento localizadas no sul do Brasil. Contagens de bactérias psicrotróficas foram entre 4,9 e 7,8 logUFC/mL e de 5,3 a 7,2 logUFC/mL, em amostras coletadas no caminhão-tanque e no silo de armazenamento da indústria, respectivamente. Dentre as bactérias isoladas, 90% foram Gram-negativas. A maioria das cepas apresentaram baixa atividade proteolítica, mas cepas de Burkholderia cepacia, Klebsiella oxytoca e Aeromonas sp. apresentaram valores superiores a 20 U/mL em azocaseina como substrato. Proteases das cepas selecionadas foram resistentes aos tratamentos térmicos convencionais e causaram coagulação de leite UAT depois de cinco dias de estocagem em temperatura ambiente. A atividade proteolítica de uma variedade psicrotrófica de Burkholderia cepacia isolada de leite cru refrigerado foi caracterizada. A atividade proteolítica na azocaseina apresentou atividade máxima com pH 6-7 e decréscimo com pHs ácido e alcalino. A enzima apresentou relativa estabilidade térmica entre 40-55°C durante 25 min, mantendo pelo menos 80% de sua atividade inicial a 40°C. O ensaio de coagulação do leite demostrou que a protease da B. cepacia causou coagulação do leite desnatado a partir do segundo dia, enquanto a coagulação do leite integral foi observada a partir do quinto dia. A aderência desta cepa ao aço inoxidável foi avaliada e os substratos apresentaram níveis de cerca de 107 UFC/cm², independente dos diferentes tempos de imersão. A cepa denominada de 1A4 apresentou expressiva atividade proteolítica em pH 6-7 e 40ºC, atividade de coagulação do leite e capacidade de aderir ao aço inoxidável. Estes resultados indicam que B. cepacia representa um potencial perigo a qualidade do leite e produtos lácteos. / Psychrotrophic bacteria were isolated from refrigerated raw milk of two processing plants at Southern Brazil. Psychrotrophic counts were between 4.9 and 7.8 log CFU/mL, and 5.3 to 7.2 log CFU/mL, for samples collected at the truck and the milk storage silo, respectively. Among the bacterial isolates, 90% were Gram-negative. Most strains presented low proteolytic activity, but strains of Burkholderia cepacia, Klebsiella oxytoca and Aeromonas sp. showed higher than 20 U/mL on azocasein as substrate. Crude proteases from selected strains were resistant to conventional heat treatments and caused coagulation of UHT milk after 5 days storage at room temperature. The proteolytic activity of a psychrotrophic strain of Burkholderia cepacia isolated from refrigerated raw milk was characterized. The proteolytic activity on azocasein showed maximum activity at pH 6-7 and decrease at acid and alkaline pHs. The enzyme showed relative thermal stability in the range 40-55°C during 25 min, maintaining at least 80% its initial activity at 40°C. Milk coagulation assay showed that the crude protease from B. cepacia caused coagulation from day 2 for skimmed milk, whereas coagulation was observed from day 5 for whole milk. The adherence of this strain to stainless steel was evaluated, and the substrata had around 107CFU/cm², regardless the different immersion time evaluated. The strain 1A4 showed elevated proteolytic activity at pH 6-7 and 40ºC, high milk coagulating-activity, and elevated capability to adhere to stainless steel. These results indicate that B. cepacia may represent a potential hazadous to milk and dairy products.