Characterization of the activity of nitrous oxide reductase: biochemical, spectroscopic and mimetic approaches

Dissertação apresentada para a obtenção do Grau de Doutor em Química Sustentável pela Universidade Nova de Lisboa, Faculdade de Ciências e Tecnologia

Antiretroviral activity of protease inhibitors against Toxoplasma gondii

The introduction of highly active antiretroviral therapy (HAART) has caused a marked reduction in the occurrence and severity of parasitic infections, including the toxoplasmic encephalitis (TE). These changes have been attributed to the restoration of cell-mediated immunity. This study was developed to examine the activity of six antiretroviral protease inhibitors (API) on Toxoplasma gondii tachyzoites. The six API showed anti-Toxoplasma activity, with IC50 value between 1.4 and 6.6 µg/mL. Further studies at the molecular level should be performed to clarify if the use of API could be beneficial or not for AIDS patients with TE.

Prophylaxis in Hemophilia A Patients with Inhibitors

The development of antibodies to factor VIII is one of the most serious complications of haemophilia treatment. Approximately 30% of patients with severe haemophilia develop neutralizing inhibitors to replacement FVIII. Although most patients with inhibitors do not bleed more frequently than patients without inhibitors, bleeding is more difficult to control and this patients suffer more severe bleeding and have greater morbidity and mortality. Patients with persistent high-titer inhibitor who are not candidates or fail ITI, pose a great challenge to haemophilia management. The efficacy and safety of prophylaxis with bypassing agents in reducing bleeding tendency, has been described in numerous studies. Patients and methods: We report tree adult severe haemophilia A patients, two with persistent high-titre inhibitors and one who failed ITI, on prophylactic treatment after several significant musculoskeletal and life-threatening haemorrhagic episodes (intrabdominal/intramuscular) and pseudotumor haemorrhage. Treatment regimens consisted of APCC (Feiba®) in doses of 60-70UKg-1, 2-3 times per week, according underlying bleeding phenotype. Breakthrough bleeds were treated with either APCC (Feiba®) or rFVIIa (NovoSeven®). Results and Conclusion: There was reduction in total bleeding episodes in two patients (43% to 80%) and one patient remained stable, while receiving prophylaxis. Absence of severe and life threatening bleeding episodes, as well as inpatient stays, contributing to a better quality of life in those patients, was observed. APCC (Feiba®) was well tolerated and no thrombotic events were observed.

The electron transfer complex between nitrous oxide reductase and its electron donors

J Biol Inorg Chem (2011) 16:1241–1254 DOI 10.1007/s00775-011-0812-9

New spectroscopic and electrochemical insights on a class I superoxide reductase: evidence for an intramolecular electron-transfer pathway

Biochem. J. (2011) 438,485–494 doi:10.1042/BJ20110836

Low-Spin Heme b3 in the Catalytic Center of Nitric Oxide Reductase from Pseudomonas nautica

Biochemistry, 2011, 50 (20), pp 4251–4262 DOI: 10.1021/bi101605p

The tetranuclear copper active site of nitrous oxide reductase: the CuZ center

J Biol Inorg Chem (2011) 16:183–194 DOI 10.1007/s00775-011-0753-3

A new CuZ active form in the catalytic reduction of N2O by nitrous oxide reductase from Pseudomonas nautica

J Biol Inorg Chem (2010) 15:967–976 DOI 10.1007/s00775-010-0658-6

Camelid nanobodies raised against an integral membrane enzyme, nitric oxide reductase

Protein Sci. 2009 Mar;18(3):619-28. doi: 10.1002/pro.69.

Electron transfer complex between nitrous oxide reductase and cytochrome c552 from Pseudomonas nautica: kinetic, nuclear magnetic resonance, and docking studies

Biochemistry. 2008 Oct 14;47(41):10852-62. doi: 10.1021/bi801375q

Biochemical and spectroscopic characterization of the membrane-bound nitrate reductase from Marinobacter hydrocarbonoclasticus 617

J Biol Inorg Chem (2008) 13:1321–1333 DOI 10.1007/s00775-008-0416-1

EPR and redox properties of periplasmic nitrate reductase from Desulfovibrio desulfuricans ATCC 27774

J Biol Inorg Chem (2006) 11: 609–616 DOI 10.1007/s00775-006-0110-0

The first crystal structure of class III superoxide reductase from Treponema pallidum

J Biol Inorg Chem (2006) 11: 548–558 DOI 10.1007/s00775-006-0104-y