How does the anaerobic human parasite Giardia intestinalis cope with oxygen?

How does the anaerobic human parasite Giardia intestinalis cope with oxygen?

Speaker: Alessandro Giuffrè

Affiliation: Department of Biochemical Sciences "A. Rossi Fanelli"
University of Roma "La Sapienza", Roma, Italy

Host: Miguel Teixeira

Abstract:

Giardia intestinalis, the most frequent protozoan agent of intestinal diseases worldwide, is an O2-susceptible amitochondriate parasite. This protozoon is highly sensitive to oxidative stress, lacking most of the conventional antioxidant defense enzymes (such as catalase, superoxide dismutase or glutathione peroxidase). This notwithstanding, it colonizes a fairly aerobic tract of the human intestine, i.e., the upper part of the small intestine. Survival and pathogenicity of Giardia should therefore rely on a fairly efficient O2-scavenging function, that is currently attributed to a FAD-containing H2O-forming NADH oxidase.
Genomic analyses showed that Giardia is one of the very few eukaryotes coding for a Flavodiiron protein (FDP), a typical prokaryotic enzyme endowed with O2- and/or NO-reductase activity. The recombinant FDP from Giardia has been characterized structurally and functionally, and found highly reactive with O2 yielding H2O as the product. This led us to hypothesize that the FDP from Giardia allows this pathogenic anaerobic parasite to cope with O2 and thus to survive in the human intestine.

Short CV:

Alessandro Giuffrè
(June, 2008)
Date and place of birth: March 6th, 1970 - Rome (Italy)
Civil status: Married, two children
Citizenship: Italian
Address: Istituto di Biologia e Patologia Molecolari del
Consiglio Nazionale delle Ricerche (CNR)
c/o Dip.to Scienze Biochimiche "A.Rossi-Fanelli"
Sapienza Università di Roma
P.le Aldo Moro 5, I-00185 Roma, Italia

ACADEMIC BACKGROUND
- 1997 PhD in Biochemistry, Sapienza University of Rome.
- 1993 University Degree in Biology at the Sapienza University of Rome.
RESEARCH EMPLOYMENTS
- Since 2001 Senior Research Fellow at the CNR Institute of Molecular Biology and Pathology (IBPM)
- 1999-2001 Research Fellow at the CNR Center of Molecular Biology.

RESEARCH INTERESTS
Structure-function, molecular evolution and control of enzymes involved in the oxygen and nitric oxide metabolism. Time-resolved spectroscopy and kinetic modeling.
INTERNATIONAL COLLABORATIONS
Prof. M.T. Teixeira (Oeiras, Portugal) – Prof. A.A. Konstantinov (Moscow, Russia) - Prof. B. Ludwig (Frankfurt, Germany) – Prof. M.T. Wilson (Colchester, United Kingdom)

TEACHING ACTIVITY
- Since 2000 Lecturer at the Course of Biomedical Laboratory Techniques - II Faculty of Medicine – Sapienza University of Rome
- 2000 3rd Course on Protein Structure-Function (L’Aquila, Italy - May 2000)
- 2002 4th Course of the Portoguese Biophysical Society (Santarem, Portugal – Oct 2002)

AWARDS and HONORS
Since 2005 Visiting Professor at the Instituto de Tecnologia Quimica e Biologica (ITQB), Universidade Nova de Lisboa (Oeiras, Porutgal)
2004 “Maria Teresa Messori Roncaglia e Eugenio Mari” award, Accademia Nazionale dei Lincei of Italy
2002 Mc. Graw-Hill award, Italian Society of Biochemistry and Molecular Biology.
1997 PhD Thesis award, Cenci-Bolognetti Foundation.
1991 “Luca Barone” award, Accademia Nazionale dei Lincei of Italy