College of Arts & Sciences

Giovanni Gadda

Giovanni Gadda Associate Professor Graduate Director Biochemistry B.Sc. (1989):  University of Milan, Italy Ph.D. (1995) :  University of Milan, Italy Postdoctoral Research Associate (1995-2000) :  Texas A&M University Dr. Giovanni Gadda Department of Chemistry Georgia State University P.O. Box 4098 Atlanta, Georgia 30302-4098 Phone:  404-413-5537 Lab Phone:  404-413-5539 Fax:  404-413-5505 Office:  549 Natural Science Center Email:  ggadda@gsu.edu

Research Interests. My research interests are in the area of mechanistic enzymology of redox enzymes with a specific interest in flavin-dependent enzymes. My objective is to understand how enzymes can influence the energetics of reaction intermediates and transition states. These aspects are being studied by steady state and pre-steady state kinetics using isotopically enriched substrates and substrate analogs. Site-directed mutagenesis and X-ray crystallography are being used to study the structures of the enzymes and the roles of individual amino acid residues. Data are being augmented by static measurements such as UV/visible and fluorescence spectroscopy. Three enzymes are currently under study: Choline oxidase, choline dehydrogenase, and 2-nitropropane diooxygenase.
 

Choline oxidase. Choline oxidase (E.C. 1.1.3.17) is a cytosolic enzyme that catalyzes the two-step oxidation of choline to betaine in the pathway for the catabolism of glycine, with betaine aldehyde as an intermediate (Scheme 1). Molecular oxygen acts as the final electron acceptor. The enzyme has been found in bacteria of the genera Arthrobacter sp. and Alcaligenes sp. Choline oxidase is a monomer of 66 kDa and contains covalently bound FAD. The recent findings that many bacterial and plant species accumulate betaine in response to salt stress or water deficit have prompted considerable interest in research on betaine biosynthesis, with the goal of genetically engineering water/osmotic stress resistance in beneficial bacteria and crop plants. Furthermore, the development of biosensors for the detection of choline and choline derivatives in serological samples renders this enzyme of medical and clinical interest. From a chemical standpoint, the mechanism of cleavage of the carbon-hydrogen bond of the substrate by choline oxidase is of particular interest because of the high energetic barrier associated with this process. Despite these reasons, choline oxidase is poorly characterized. Three mechanisms consistent with available studies can be proposed, in which the carbon-hydrogen bond is cleaved by removal of a hydride, through a radical, or after formation of an alkoxide intermediate (Scheme 2).

The Arthrobacter choline oxidase has been cloned in E. coli by the group of Dr. Murata, National Institute for Basic Biology, Okazaki, Japan. This recombinant enzyme is being used in our laboratory to obtain amounts suitable for mechanistic and structural studies. A number of kinetic approaches, such as product inhibition, pH-profiles, kinetic isotope effects using isotopically enriched substrates, and solvent isotope effects, are being used in the study. Data obtained from any of these methods will be augmented with data obtained using substrate analogs and mutant proteins. Rapid reaction kinetics of both the reductive half-reaction in which the enzyme is reduced by the substrate and of the oxidative half-reaction in which oxygen accepts the electron pair from the enzyme to regenerate the oxidized enzyme will also be performed.The determination of the site of flavinylation in the sequence will allow construction of a protein with non-covalently bound FAD to be used to selectively replace FAD with artificial flavins of different redox potentials, providing a powerful tool for studying the electron transfer reactions. Since the three dimensional structure of the enzyme is not available, the involvement of specific amino acid residues in catalysis will be initially investigated by chemical modification studies with specific reagents and subsequently by mutagenesis.

Choline Dehydrogenase. The oxidation of choline to betaine can also be catalyzed by choline dehydrogenase (CHD; E.C. 1.1.99.1), a membrane-bound enzyme. Two types of choline dehydrogenase have been described, which differ in the prosthetic group (FAD or pyrrolo-quinoline quinone, PQQ). While a wealth of biochemical studies have been recently reported for the PQQ-dependent enzyme, little is known of the FAD-dependent CHD. The latter enzyme has been found in rat liver, in E. coli, and in Sinorhizobium melilori. CHD belongs to the GMC family, which includes cholesterol oxidase, methanol oxidase, glucose dehydrogenase, and glucose oxidase. By sequence alignment, choline oxidase can be included in this family. Although CHD from E. coli shows significant similarity to choline oxidase (52% identify and 68% similarity), it does not react with molecular oxygen. Instead, coenzyme Q has been proposed to serve as the final electron acceptor. The same reasons described above for choline oxidase hold for the study of CHD. Moreover, the origin of the selectivity of CHD for the oxidizing substrate is of considerable interest. The mechanistic and structural properties that confer to reduced flavoproteins the ability to react with oxygen are not known. The comparative study of the mechanisms of CHD and choline oxidase offers a model for gaining insights on how the reactivity of reduced flavins for oxygen is regulated by the protein microenvironment. The recombinant enzyme from Sinorhyzobium melilori (a gift from Dr. Le Rudulier, Universite' de Nice-Sophia Antipolis, France) is currently available in the laboratory and will be the focus of the initial studies.
 

2-Nitropropane dioxygenase. 2-Nitropropane dioxygenase (2-NPD) is found in yeast and catalyzes the oxidation of 2-nitropropane to acetone and nitrite (Scheme 3). The study of an enzyme capable of oxidizing nitroalkanes is of considerable interest for several reasons. Nitroalkanes are widely used as industrial solvents, chemical intermediates, explosives, and fuels. Several nitroalkanes have been shown to be toxic and/or carcinogenic. Thus, an enzymatic activity that converts these compounds into less harmful species is of interest for bioremediation. In addition, aliphatic nitroalkanes were not found at significant levels in the environment until recently. Thus, 2-NPD appears to be an example of a recently evolved enzyme. The study of 2-NPD can provide insight into how organisms evolve enzymes to deal with environmental changes. From a chemical standpoint, 2-NPD is of interest because it offers an opportunity to expand the array of the reactions catalyzed by flavoproteins and the ways in which proteins can modulate the reactivity of the isoalloxazine ring of the flavin.

Hansenula mrakii and Neurospora crassa 2-NPD have been cloned in E. coli by the group of Dr. Esaki (Kyoto University, Japan) and are available in the laboratory. While the two enzymes have molecular weights of about 40 kDa, they differ in their prosthetic group content, in that FAD and FMN are found in the Hansenula and Neurospora 2-NPD, respectively. Pre-steady state and steady state analyses will be performed to determine the kinetic mechanism for 2-NPD with 2-nitropropane. The data obtained will be augmented with data obtained using a number of different nitroalkanes as substrate, such as nitroethane, 1-nitropropane, and phenylnitromethane. Kinetic isotope effects and pH dependence studies with isotopically enriched substrates will be used to determine conditions under which the cleavage of the carbon-hydrogen bond is rate-limiting for catalysis, to obtain information about the stickiness of substrates, and as probes of events after carbon-hydrogen cleavage.

Affiliations:

American Society of Biochemistry and Molecular Biology (2001-present)
American Chemical Society (2001-present)
American Society for Microbiology (2003-present)
American Association for the Advancement of Science (1999-present)

Peer-Reviewed Journal Articles:

1. Gadda, G., Aliverti, A., Ronchi, S. and Zanetti, G. (1990) Structure-Function Relationship in Spinach Ferredoxin-NADP+ Reductase as Studied by Limited Proteolysis, J. Biol. Chem. 265, 11955-11959.
2. Aliverti, A., Gadda, G., Ronchi, S. and Zanetti, G. (1991) Identification of Lysine 116 as the Target of N-ethylmaleimide Inactivation of Ferredoxin-NADP+ Oxidoreductase, Eur. J. Biochem. 198, 21-24.
3. Gadda, G., Negri, A. and Pilone, M.S. (1994) Reaction of Phenylglyoxal with Arginine Groups in D-Amino Acid Oxidase from Rhodotorula gracilis, J. Biol. Chem. 269, 17809-17814.
4. Gadda, G., Beretta, G.L. and Pilone, M.S. (1995) Reactivity of Histidyl Residues in D-Amino Acid Oxidase from Rhodotorula gracilis, FEBS Lett. 363, 307-310.
5. Gadda, G., Beretta, G.L. and Pilone, M. (1994) Chemical Modification of Lysyl Residues of Rhodotorula gracilis  D-Amino Acid Oxidase, Biochem. Mol. Biol. Int. 33, 947-955.
6. Gadda, G., Edmondson, R.D., Russell, D.H. and Fitzpatrick, P.F. (1997) Identification of the Naturally Occurring Flavin of Nitroalkane Oxidase from Fusarium oxysporum as a 5-Nitrobutyl-1,5-dihydroflavin and Conversion of the Enzyme to the Active FAD-Containing Form, J. Biol. Chem. 272, 5563-5570.
7. Edmondson, R.D., Gadda, G., Fitzpatrick, P.F. and Russell, D.H. (1997) Identification of Native Flavin Adducts from Fusarium oxysporum Using Accurate Mass Matrix-Assisted Laser Desorption/Ionization Time-of-Flight Mass Spectrometry, Anal. Chem. 69, 2862-2865.
8. Gadda, G., Wels, G., Pollegioni, L., Zucchelli, S., Ambrosius, D., Pilone, M.S. and Ghisla, S. (1997) Characterization of Cholesterol Oxidase from Streptomyces hygroscopicus and Brevibacterium sterolicum, Eur. J. Biochem. 250, 369-376.
9. Gadda, G., and Fitzpatrick, P.F. (1998) Biochemical and Physical Characterization of the Active FAD-Containing Form of Nitroalkane Oxidase from Fusarium oxysporum, Biochemistry 37, 6154-6164.
10. Gadda, G., and Fitzpatrick, P.F. (1999) Substrate Specificity of a Nitroalkane Oxidizing Enzyme, Arch. Biochem. Biophys.363, 309-313.
11. Gadda, G., Dangott, L.J., Johnson, W.H.Jr., Whitman, C.P., and Fitzpatrick, P.F. (1999) Characterization of 2-Oxo-3-Pentynoate as an Active-Site-Directed Inactivator of Flavoprotein Oxidases: Identification of Active-Site Peptides in Tryptophan 2-Monooxygenase, Biochemistry 38, 5822-5828.
12. Pollegioni, L., Gadda, G., Ambrosius, D., Ghisla, S., and Pilone, M.S. (1999) Cholesterol Oxidase from Streptomyces hygroscopicus and Brevibacterium sterolicum: Effect of Surfactants and Organic Solvents on Activity, Biotechol. Appl. Biochem. 30, 27-30.
13. Gadda, G., Banerjee, A., and Fitzpatrick, P.F. (2000) Identification of an Essential Tyrosine Residue in Nitroalkane Oxidase by Modification with Tetranitromethane, Biochemistry 39, 1162-1168.
14. Gadda, G., and Fitzpatrick, P.F. (2000) Iso-Mechanism of Nitroalkane Oxidase: 1. Inhibition Studies and Activation by Imidazole, Biochemistry 39, 1400-1405.
15. Gadda, G., and Fitzpatrick, P.F. (2000) Mechanism of Nitroalkane Oxidase: 2. pH and Kinetic Isotope Effects, Biochemistry 39, 1406-1410.
16. Gadda, G., Choe, D.Y., and Fitzpatrick, P.F. (2000) Use of pH and Kinetic Isotope Effects to Dissect the Effects of Substrate Size on Binding and Catalysis by Nitroalkane Oxidase, Arch. Biochem. Biophys. 382, 138-144.
17. Gadda, G., Banerjee, A., Dangott, L.J., and Fitzpatrick, P.F. (2000) Identification of a Cysteine Residue in the Active Site of Nitroalkane Oxidase by Modification with N-ethylmaleimide, J. Biol. Chem. 275, 31891-31895.
18. Gadda, G., Banerjee, A., Fleming, G.S., and Fitzpatrick, P.F. (2001) Evidence for An Essential Arginine In the Active Site of Nitroalkane Oxidase, J. Enzyme Inhibition 16, 157-163.
19. Daubner, S.C, Gadda, G., Valley, M.P., and Fitzpatrick, P.F. (2002) Cloning of Nitroalkane Oxidase from Fusarium oxysporum Identifies a New Member of the Acyl-CoA Dehydrogenase Superfamily, Proc. Nat. Acad. Sci. USA 99, 2702-2707.
20. Gadda, G. (2003) Kinetic Mechanism of Choline Oxidase from Arthrobacter globiformis, Biochim. Biophys. Acta 1646(1-2), 112-118.
21. Gadda, G., and McAllister-Wilkins, E.E. (2003) Cloning, Expression, and Purification of Choline Dehydrogenase From the Moderate Halophile Halomonas elongata, Appl. Environ. Microbiol. 69(4), 2126-2132.
22. Gadda, G. (2003) pH and Deuterium Kinetic Isotope Effects Studies on the Oxidation of Choline to Betaine-Aldehyde Catalyzed by Choline Oxidase, Biochim. Biophys. Acta 1650(1-2), 4-9.
23. Ghanem, M., Fan, F., Francis, K., and Gadda, G. (2003) Spectroscopic and Kinetic Properties of Recombinant Choline Oxidase from Arthrobacter globiformis, Biochemistry 42, 15179-15188.
24. Fan, F., Ghanem, M., and Gadda, G. (2004) Cloning, Sequence Analysis, and Purification of Choline Oxidase from Arthrobacter globiformis: a Bacterial Enzyme Involved in Osmotic Stress Tolerance, Arch. Biochem. Biophys. 421, 149-158.
25. Gadda, G., Powell, N.L.N., and Menon, P. (2004) The Trimethylammonium Headgroup of Choline is a Major Determinant for Substrate Binding and Specificity in Choline Oxidase, Arch. Biochem. Biophys., 430, 264-273.
26. Fan, F., and Gadda, G. (2005) On the Catalytic Mechanism of Choline Oxidase, J. Am. Chem. Soc. U.S.A., Published on the Web on Jan. 25th, 2005.
27. Ghanem, M., and Gadda, G. (2005) On the Catalytic Role of the Conserved Active Site His466 of Choline Oxidase, Biochemistry, 44, 893-904.
28. Francis, K., Russell, B., and Gadda. G. (2005) Involvement of a Flavosemiquinone in the Enzymatic Oxidation of Nitroalkanes Catalyzed by 2-Nitropropane Dioxygenase, J. Biol. Chem., 280, 5195-5204.
29. Fan, F., and Gadda, G. (2005) Oxygen- and Temperature-Dependent Kinetic Isotope Effects in Choline Oxidase: Correlating Reversible Hydride Transfer with Environmentally Enhanced Tunneling, J. Am. Chem. Soc. U.S.A., 127, 17954-17961.
30. Fan, F., Germann, M.W., and Gadda, G. (2006) Mechanistic Studies of Choline Oxidase with Betaine Aldehyde and its Isosteric Analog 3,3-Dimethylbutyraldehyde, Biochemistry, 45, 1979-1986.
31. Ghanem, M., and Gadda, G. (2006) Effects of Reversing the Protein Positive Charge in Proximity of the N(1) Flavin Locus of Choline Oxidase, Biochemistry, 45, 3437-3447.
32. Gadda, G., Fan, F., and Hoang, J.V. (2006) On the Contribution of the Positively Charged Headgroup of Choline to Substrate Binding and Catalysis in the Reaction Catalyzed by Choline Oxidase, Arch. Biochem. Biophys., 451,182-187.
33. Francis, K, and Gadda, G. (2006) Probing the Chemical Steps of Nitroalkane Oxidation Catalyzed by 2-Nitropropane Dioxygenase with Solvent Viscosity, pH, and Substrate Kinetic Isotope Effects, Biochemistry, 45, 13889-13898.
34. Hoang, J.V., and Gadda, G. (2007) Trapping Choline Oxidase in a Nonfunctional Conformation by Freezing at Low pH, Proteins, 66, 611-620.
35. Zargari, A., Selander, C., Rasool, O., Ghanem, M., Gadda, G., Crameri, R., and Scheynius, A. (2007) Mala s 12 is a Major Allergen in Patients with Atopic Eczema and has Sequence Similarities to the GMC Oxidoreductase Family, Allergy, 62, 695-703.
36. Fan, F., and Gadda, G. (2007) An Internal Equilibrium Preorganizes the Enzyme-Substrate Complex for Hydride Tunneling in Choline Oxidase, Biochemistry, 46, 6402-6408.
37. Zou, J., Hofer, A.M., Lurtz, M.M., Gadda, G., Ellis, A.L., Chen, N., Huang, Y., Holder, A., Louis, C., Welshhans, K., Rehder, V., and Yang, J.J. (2007) Developing Sensors for real Time Measurement of High Ca⁺⁺ Concentrations, Biochemistry, 46, 12275-12288.
38. Quaye, O., Lountos, G.T., Fan, F., Orville, A.M., and Gadda, G. (2007) Role of Glu³¹² in Binding and Positioning of the Substrate for Hydride Transfer Reaction in Choline Oxidase, Biochemistry, 47, 243-256.
39. Pennati, A., Aliverti, A., Zanetti, G., and Gadda, G. (2008) Effect of Salt and pH on the Reductive Half-Reaction of Mycobacterium tuberculosis FprA with NADPH, Biochemistry, 47, 3418-3425.
40. Mijatović, S., and Gadda, G. (2008) Oxidation of Alkyl Nitronates Catalyzed by 2-Nitropropane Dioxygenase from Hansenula mrakii, Arch. Biochem. Biophys., 473, 61-68.
41. Rungsrisuriyachai K., and Gadda, G. (2008) On the Role of Histidine 351 in the Reaction of Alcohol Oxidation Catalyzed by Choline Oxidase, Biochemistry, 47, 6762-6769.
42. Francis, K., and Gadda, G. (2008) The non-oxidative conversion of nitroethane to ethylnitronate in Neurospora crassa 2-nitropropane dioxygenase is catalyzed by histidine 196, Biochemistry, 47, 9136-9144.
43. Finnegan, S., and Gadda, G. (2008) Substitution of an Active Site Valine Uncovers a Kinetically Slow Equilibrium between Competent and Incompetent Forms of Choline Oxidase, Biochemistry, 47, 13850-13861.
44. Gadda, G. (2008) Hydride Transfer Made Easy in the Reaction of Alcohol Oxidation Catalyzed by Flavin-dependent Oxidases, Biochemistry, 47, 13745-13753.
45. Kamio, M., Ko, C., Zheng, S., Wang, B., Collins, S.L., Gadda, G., Tai, P.C., and Derby, C.D. (2009) The Chemistry of Escapin: Identification and Quantification of the Components in the Complex Mixture Generated by an L-Amino Acid Oxidase in the Defensive Secretion of the Sea Snail Aplysia californica, Chemistry, 15, 1597-1603.
46. Rungsrisuriyachai, K., and Gadda, G. (2009) A pH Switch Affects the Steady-State Kinetic Mechanism of Pyranose 2-Oxidase from Trametes ochracea, Arch. Biochem. Biophys. 483, 10-15.
47. Orville, A.M., Lountous, G.T., Finnegan, S., Gadda, G., and Prabhakar, R. (2009) Crystallographic, Spectroscopic, and Computational Analysis of a Flavin-C4a-Oxygen Adduct in Choline Oxidase, Biochemistry, 48, 720-728.
48. Francis, K., and Gadda, G. (2009) Inflated Kinetic Isotope Effects in the Branched Mechanism of Neurospora crassa 2-Nitropropane Dioxygenase, Biochemistry, 48, 2403-2410.
49. Chen, N., Zou, J., Wang, S., Ye, Y., Huang, Y., Gadda, G., and Yang, J. (2009) Designing Protease Sensors for Real-time Imaging of Trypsin Activation in Pancreatic Cancer Cells, Biochemistry, 48, 3519-3526.
50. Quaye, O., Cowins, S., Gadda, G. (2009) Contribution of Flavin Covalent Linkage with Histidine 99 to the Reaction Catalyzed by Choline Oxidase, J. Biol. Chem., 284, 16990-16997.
51. Gadda, G., and Francis, K. (2009) Nitronate Monooxygenase, a Model for Anionic Flavin Semiquinone Intermediates in Oxidative Catalysis, Arch. Biochem. Biophys., in press.
52. Francis, K., and Gadda, G. (2009) Kinetic Evidence for an Anion Binding Pocket in the Active Site of Nitronate Monooxygenase, Bioorg. Chem., in press.
53. Quaye, O., and Gadda, G. (2009) Effect of a Conservative Mutation of an Active Site Residue Involved in Substrate Binding on the Hydride Tunneling Reaction Catalyzed by Choline Oxidase, Arch. Biochem. Biophys., in press.
54. Xin, Y., Gadda, G., and Hamelberg, D.(2009) Cluster of Hydrophobic Residues Controls the Entrance to the Active Site of Choline Oxidase, Biochemistry, in press.
55. Pennati, A., and Gadda, G. (2009) Involvement of Ionizable Groups in Catalysis of Human Liver Glycolate Oxidase, J. Biol. Chem., in press.

Book Chapters:

1. Edmondson, D.E. and Gadda, G. (2008) Guidelines for the Functional Analysis of Engineered and Mutant Enzymes; in Protein Engineering Handbook; S. Lutz and U.T. Bornscheuer Eds.; Wiley-VCH.

Book Reviews:

   1. Gadda, G. (2007)Flavins: Photochemistry and Photobiology. Comprehensive Series in Photochemical and Photobiological Sciences Edited by Eduardo Silva and Ana M. Edwards (P. Universidad Catolica de Chile, Santiago). Royal Society of Chemistry: Cambridge. 2006. x + 328 pp. $329.00. ISBN 0-85404-331-4. J. Am. Chem. Soc. 2007 Jul 18;129(28):8926.

Conference Proceedings (Contributed Papers):

1. Gadda, G., Aliverti, A., Ronchi, S. and Zanetti, G. (1991) Ferredoxin Binding Site of Ferredoxin-NADP⁺ Reductase as Explored by Limited Proteolysis and Mutagenesis, in Flavins and Flavoproteins  (Curti, B., Ronchi, S. and Zanetti, G., eds.) pp. 465-468, Walter de Gruyter, Berlin.
2. Gadda, G., Negri, A. and Pilone, M.S. (1994) Chemical Modification of Arginine Groups in D-Amino Acid Oxidase from Rhodotorula gracilis, in Flavins and Flavoproteins   (Yagi, K., ed.) pp. 167-170, Walter de Gruyter, Berlin.
3. Faotto, L., Pollegioni, L., Ceciliani, F., Gadda, G., Ronchi, S. and Pilone, M.S. (1994) Amino Acid Sequence of D-Amino Acid Oxidase from the Yeast Rhodotorula gracilis, in Flavins and Flavoproteins  (Yagi, K., ed.) pp. 163-166, Walter de Gruyter, Berlin.
4. Gadda, G., and Fitzpatrick, P.F. (1997) Characterization of the Flavin Adduct of Nitroalkane Oxidase, in Flavins and Flavoproteins  (Stevenson, K.J., Massey, V. and Williams, C.H.Jr., eds.) pp. 147-150, University of Calgary Press, Calgary.
5. Fitzpatrick, P.F., Kurtz, K., Gadda, G., Rishavy, M., and Cleland, W.W. (1999) Mechanisms of Flavoprotein Oxidases, in Proceedings of the 26^th Steenbock Symposium (Frey, P.A., and Northrop, D.B., eds.) pp. 176-186, IOS Press, Amsterdam.
6. Gadda, G., and Fitzpatrick, P.F. (2000) An Iso-Mechanism for Nitroalkane Oxidase: Evidence for a Slow Proton Transfer to Solvent Coupled to Isomerization of the Free reduced Enzyme, in Flavins and Flavoproteins, (Ghisla, S., Kroneck, P., Sund, H., and Macheroux, P., eds.) pp. 639-642, Rudolf Weber, Berlin, Germany.
7. Gadda, G. (2002) Mechanistic Studies on Choline Oxidase From Arthrobacter globiformis, in Proceedings of the Fourteenth International Symposium on Flavins and Flavoproteins, (Perham, R.N., Chapman, S.K., Scrutton, N.S., eds.) p. 181-186, Rudolf Weber, Berlin, Germany.
8. Powell, N., Fan, F., Wilkins, L., and Gadda, G. (2002) Comparative Study of Choline Oxidizing Enzymes From Escherichia coli, Halomonas elongata, and Arthrobacter globoiformis, in Proceedings of the Fourteenth International Symposium on Flavins and Flavoproteins, (Perham, R.N., Chapman, S.K., Scrutton, N.S., eds.) p. 149-154, Rudolf Weber, Berlin, Germany.
9. Russell, B., Johnson, K.L., Seyfe, D., and Gadda, G. (2002) Purification and Characterization of Recombinant 2-Nitropropane Dioxygenase From Neurospora crassa and  Hansenula mrakii, in Proceedings of the Fourteenth International Symposium on Flavins and Flavoproteins, (Perham, R.N., Chapman, S.K., Scrutton, N.S., eds.) p. 229-234, Rudolf Weber, Berlin, Germany.
10. Daubner, S.C., Gadda, G. Valley, M.P., and Fitzpatrick, P.F. (2002) Nitroalkane Oxidase from Fusarium oxysporum is a Member of the Acyl-CoA Dehydrogenase Superfamily, in Proceedings of the Fourteenth International Symposium on Flavins and Flavoproteins, (Perham, R.N., Chapman, S.K., Scrutton, N.S., eds.) p. 981-986, Rudolf Weber, Berlin, Germany.
11. Fitzpatrick, P.F., Valley, M.P., Gadda, G., Nagpal, A., and Orville, A.M. (2005)  The Mechanism of Nitroalkane Oxidase, in Proceedings of the Fifteen International Symposium on Flavins and Flavoproteins, (Nishino, T., Miura, R., Tonukora, M., and Fukui, K., eds.) p. 59-69, Archi Tect inc, Tokyo, Japan.
12. Gadda, G., Pennati, A., Francis, K., Quaye, O., Yuan, H., Rungsrisuriyachai, K., Finnegan, S., Mijatovic, S., Nguyen, T., and Orville, A.M. (2008) Hydride Transfer Made Easy in the Oxidation of Alcohols Catalyzed by Choline Oxidase, in Proceedings of the Sixteenth International Symposium on Flavins and Flavoproteins.

Courses Taught at Georgia State University:

1. Advanced Topics in Biochemistry – Principles and Techniques of Practical Biochemistry (Chem 8620 – offered to PhD students in Chemistry and Biology): Fall Semester 2009.
2. Biochemistry I (CHEM 4600/6600:  offered to undergraduate and graduate students):  Fall Semester 2000; Spring Semester 2001; Fall Semester 2001; Fall Semester 2002; Fall Semester 2003; Spring Semester 2004; Spring 2005; Fall 2006; Fall 2007; Fall 2008.
3. Enzymology (CHEM 4630/6630; BIOL 4630/6640:  offered to undergraduate and graduate students): Spring Semester 2002; Spring Semester 2003; Fall 2004; Fall 2005; Spring 2007.  This course has been proposed and developed by Dr. Giovanni Gadda and has been offered at Georgia State University for the first time in the Spring Semester 2002.
4. Advanced Research Methods (CHEM 4900-004/6900-004:  offered to undergraduate and graduate students): Spring 2005; Fall 2005; Spring 2006; Fall 2006; Spring 2007; Fall 2007; Spring 2008; Fall 2008; Spring 2009; Fall 2009.
5. Instructor at the NSF Center for Workshop in the Chemical Sciences  Molecular Genetics and Protein Structure/Function Techniques Georgia State University August 2001, August 2002 (http://chemistry.gsu.edu/CWCS/genetics.html).

Research Advisor at Georgia State University (Past):

1. John T. Kanazawa, Undergraduate Student in Chemistry, January 2001 to September 2001 (Bachelor in Science).
2. Bethany Russell, Undergraduate Student in Chemistry, January 2001 to December 2001 (Bachelor in Science); Master of Science in Chemistry, January 2002 to December 2002. (Master of Science).
3. Katina L. Johnson, Undergraduate Student in Chemistry, January 2001 to December 2001 (Bachelor in Science); Master of Science Student in Chemistry, January 2002 to August 2002.
4. Elien McAllister, Undergraduate Student in Chemistry, January 2001 to December 2001 (Bachelor in Science); Master of Science in Chemistry, January 2002 to December 2002. (Master of Science).
5. Dawit Seyfe, Undergraduate Student in Biology, August 2001 to June 2002. (Bachelor in Science); McNair Post-Baccalaureate Fellow (Chemistry), May 2001 ad August 2001.
6. Thaddeus Harvey II, McNair Post-Baccalaureate Fellow (Biology), May 2001 to August 2001.
7. Brittany Bivines, McNair Post-Baccalaureate Fellow (Biology), June 2002 to August 2002
8. Sandra Imarah, McNair Post-Baccalaureate Fellow (Biology), June 2002 to August 2002.
9. Aisha Tolbert, Bridges to the Future Fellow (Chemistry), May 2003 to July 2003.
10. Kevin Francis, McNair Post-Baccalaureate Fellow (Biology), June 2003 to August 2003; Undergraduate in student in Biology January 2003 to August 2004.
11. Tranbao N?Guyen, McNair Post-Baccalaureate Fellow (Chemistry), June 2003 to August 2003; Undergraduate in Chemistry, August 2003 to December 2005.
12. Nichole L. N. Powell, Ph.D. Student in Chemistry, March 2001 to December 2003.
13. Bhavisha Patel, Undergraduate in Biology, August 2003 to August 2004.
14. Prashanthi Menon, Master of Science in Biology, May 2003 to May 2004.
15. Fan Fan, Ph.D. Student in Biology, August 2001 to December 2005.
16. Thuy-Trang Hoang, Undergraduate Student in Chemistry, January 2004 to August 2005 (Bachelor in Science).
17. Mahmoud Ghanem, Ph.D. Student in Chemistry, May 2002 to May 2006.
18. Jane (Thuy-Trang) V. Hoang, Master of Science in Chemistry, August 2005 to August 2006.
19. Anthony Mgbodile, McNair Post-Baccalaureate Fellow, May 2006 to August 2006.
20. Slavica Mijatovic, Undergraduate Student in Chemistry, January 2006 to August 2006.
21. Kevin Francis, Master of Science in Chemistry, August 2004 to May 2007.
22. Merid Belaineh, Undergraduate Student in Chemistry, and McNair Post-Baccalaureate Fellow (Chemistry), June 2005 to December 2006.
23. Stacy Collins, Undergraduate Student in Biology, March 2007 to August 2007.
24. Slavica Mijatovic, Master of Science in Chemistry, August 2006 to May 2008.
25. Tranbao Nguyen, Master of Science in Chemistry, August 2006 to December 2007. 
26. Sharonda Cowins, Summer Intern, May 2008 to August 2008.
27. Danila Crobu, PhD exchange-student from University of Milano, Milan, February 2009 to April 2009.
28. Nicole Chapman, BS Student in Chemistry, August 2008 to May 2009.
29. Phillip Brook, BS in Chemistry, January 2009 to May 2009.
30. Osbourne Quaye, Ph.D. Student in Chemistry, January 2005 to August 2009.

Research Advisor at Georgia State University (Present):

1. Dr. Andrea Pennati, Post-Doctoral Research Associate, May 2007 to present.
2. Kevin Francis, Ph.D. Student in Chemistry, August 2006 to present.
3. Kunchala Rungsrisuriyachai, Ph.D. Student in Chemistry, January 2005 to present.
4. Steffan Finnegan, Ph.D. Student in Chemistry, January 2006 to present.
5. Hongling Yuan, Ph.D. Student in Chemistry, August 2006 to present.
6. Lydia Law, MS Student in Chemistry, August 2008 to present.
7. Stephen Sherman, BS Student in Chemistry, August 2008 to present. 
8. Swathi Gannavaram, Ph.D. Student in Chemistry, August 2009 to present.

Direction of Individual Student Work (Thesis and Dissertations):

1.Silvia Zucchelli, Tesi di Laurea in Scienze Biologiche: July 1995. Title “Colesterolo Ossidasi da Streptomyces hygroscopicus”; Dipartimento di Fisiologia e Biochimica Generali, Universita’ degli Studi di Milano, Milano, Italy. Co-Advisor.

2.Giovanni Luca Beretta, Tesi di Laurea in Scienze Biologiche: 1995. Title “Studio del Sito Attivo della D-Amminoacido Ossidasi da Rhodotorula gracilis Mediante Modifica Chimica”; Dipartimento di Fisiologia e Biochimica Generali, Universita’ degli Studi di Milano, Milano, Italy. Co-Advisor.

3.Bethany Russell, M.S. Thesis: December 2002. Title: ”Purification and Partial Characterization of Recombinant 2-Nitropopane Dioxygenase from Neurospora crassa”; Chemistry Department, Georgia State University, Atlanta, GA, U.S.A.

4.Nichole Powell, Ph.D. Dissertation: December 2003. Title: " Bacterial Choline-Oxidizing Systems: Characterization of Enzymes Involved in Stress Tolerance and The Roles of Cytochrome P450s 1A1, 1A2, and 2D6, and the GSTM1 Genes in Treatment Resistant Depression"; Chemistry Department, Georgia State University, Atlanta, GA, U.S.A.

5.Fan Fan, PhD Dissertation: December 2005. Title: "On the Catalytic Mechanism of Choline Oxidase"; Biology Department, Georgia State University, Atlanta, GA, U.S.A.

6.Mahmoud Ghanem, PhD Dissertation: March 2006. Title: "On the Mechanistic Roles of the Protein Positive Charge Close to the N(1) Flavin Locus of Choline Oxidase"; Chemistry Department, Georgia State University, Atlanta, GA, U.S.A.

7.Jane V. Hoang, M.S. Thesis: August 2006. Title: ”Inactivation of Choline Oxidase by Irreversible Inhibitors or Storage Conditions”; Chemistry Department, Georgia State University, Atlanta, GA, U.S.A.

8.Mijatovic Slavica, M.S. Thesis: May 2008. Title: “Biochemical Characterization of 2-Nitropropane Dioxygenase from Hansenula mrakii”; Chemistry Department, Georgia State University, Atlanta, GA, U.S.A.

9.Osbourne Quaye, PhD Dissertation: August 2009. Title: “On the Pre-Organization of the Active Site of Choline Oxidase for the Hydride Transfer and Tunneling Mechanism”; Chemistry Department, Georgia State University, Atlanta, GA, U.S.A.