Manuel Aureliano, PhD

Assistant Professor

Biochemistry, Inorganic Biochemistry and Cell Biology

DQB, FCT, Algarve University, Faro, Portugal

e-mail: maalves@ualg.pt

M. Aureliano has been Director and vice-director of the Biochemistry degree (Algarve University) from 1997/98 to 2002/03.

(Link to:http://www.ualg.pt/fct/quimica/Bioquimica.html) or http://www.fct.ualg.pt/bioquimica.

Disciplines

first semestre: Bioquímica Geral I (2nd year) Metais e Metabolismo (3 and 4th years);

second semestre: Biologia Celular(first year); Tópicos Avançados em Biologia Celular (3 and 4^th years)

Information 2004/05:

Licenciatura em Bioquímica

Biologia Celular (1º ano)

2004/2005

Informação final após exame (01/07/05)

Nome do aluno, nº	Classificação
Rita Pessoa, 27936	16
Maria Rodrigues, 27928	16
Andreia Loureço, 21564	15
Célia Domingos, 27918	15
Paulo Ferreira, 27933	14
Denise Schrama, 25557	14
Ana Eufigénia, 23613	14
Diana Lopes, 27920	14
Telma Silva, 25914	14
Joana Cristo, 27925	14
Joana Alho, 25038	13
Míriam Jesus, 25045	13
Sabrina Bota, 25053	13
Catarina Nobre, 27917	13
Pedro Ramos, 25049	13
Henrique Batista, 27924	13
Joel Pires, 27926	13
Ana Correia, 27914	13
Ana Jesus, 28984	13
Mário Borges, 25042	13
Susana Viegas, 28985	12
Sara Evaristo, 27938	12
Rosa Brissos, 25052	12
Diogo Cordeiro, 27927	12
Cláudia Pedro, 27919	12
Vânia Martins, 28987	12
João Roberto, 21841	12
Telma Mateus, 28986	12
Regina Silva, 27934	11
Heloísa Neto, 27923	11
Filipa Rodrigues, 27922	11
Ana Fidalgo, 23614	11
Mónica Gomes, 27930	11
Maria Fernandes, 29147	11
Mónica Faria, 27931	10
Rui Lopes, 27937	10
Andreia Silva, 24171	10

Prof. M. Aureliano Alves

Campus de Gambelas, 4 de Julho de 2005

Tópicos Avançados em Biologia Celular

(Lic. Bioquímica; 4º ano, 2ºS, 2004/05)

(Informação Final de Frequência)

1	Nome	Artigo A Apresentação Oral e Defesa 20%	Artigo B Apresentação Oral e Defesa 20%	Monografia 1 20%	Monografia Final  40%	Classif. Final
	Claúdia Oliveira,17107	16,5	16	16,5	18	17
	Karina Pires, 19324	16	16	16	18	17
	Vanda Pinto, 18931	17	18	17	19	18
	Margarida Neto, 20139	15	15	15	17	16
	Dorinda Silva, 21563	16	17	16,5	18	17
	Susana Ramos, 24034	18	19	17	19	19
	Rogério Rodrigues, 17512	16	---	---	---	*
	Pedro Bastos	---	---	---	---	*

• Falar com o Professor (falta entrega de trabalho)

Research topics:

1) Interaction of vanadate with myosin/actin

2) Vanadate complexes effects on calcium pump

3) Cellular responses induced by vanadate

(Link to: http://www.ualg.pt/fct/quimica/Aureliano_Alves.html)

Research team:

Postdoctoral fellow: Rui Duarte

PhD students: Teresa Tiago, Sandra Soares, Daniel Tiago, Gisela Borges.

Gradute students: Andrea Sousa, (Master Student) Ricardo Gândara, Maria João Pereira, Adélia Moderno

Undergraduate students: Ana Pereira, Sandra Alves, Sónia Simão

(Link to: http://www.fct.ualg.pt/biovanadium)

Resume of scientific interest

Vanadium is widely known for its toxic effects, however it is vestigial in muscles and other tissues and is considered an essential oligoelement for humans. Its biological role is far from a clear identification. Vanadium is present in petroleum, coal and gasoline, used as alloys and catalysts for industry and is well known for its environmental and biological impact.

Most of the biological importance of vanadium is associated with the +5 oxidation state (vanadate) probably due to similarities between the phosphate and vanadate chemistries in solution. In vanadium (+5) solutions different oligomeric (n=1 to 10) vanadate species can occur simultaneously in equilibrium such as monomeric (V1), dimeric (V2), tetrameric (V4) and decameric (V10) and, in same cases, with different states of protonation and forms.

Many of these vanadate species are not taken in consideration in the majority of the biological studies, although it is known that they may also influence enzyme activity. The effects can be conveniently analysed combining kinetic with spectroscopy studies. With the sarcoplasmic reticulum calcium pump and myosin experiments can be design to detect different interactions and different effects for several oligomeric vanadate species. Allegorically, vanadate studies in biological systems compare to iceberg phenomena, being of crucial importance to precisely characterize the vanadate species and the interactions with the system before attempting to understand the promoted effects.

1) Myosin is a highly specialized protein that converts the chemical energy of ATP hydrolysis to mechanical work. This activity is greatly enhanced when actin binds to myosin forming the actomyosin complex. It is known that myosin is inhibited by vanadate due to the similarity with phosphate. However, the effects of other species of vanadate on the activity of myosin and actomyosin have not yet been clarified. It was demonstrated that, under conditions near physiological ones, decameric vanadate differs from vanadate oligomers present in metavanadate solutions due to its strong interaction with the phosphorylated enzyme and myosin ATPase inhibition. Besides, ATP decreases the affinity of myosin for tetravanadate, induces the interaction with monomeric vanadate, whereas does not affect decameric vanadate interaction. Moreover, is was described that the binding of decavanadate to high affinity sites in myosin are due to local conformational change(s) near the tryptophans of myosin more accessible to water in the three-dimensional structure of this protein (Tiago et. al., 2002a and 2002b).

2) Sarcoplasmic reticulum (SR) Ca²⁺-ATPase is a transmembrane transport system, which accumulates Ca²⁺ at expense of ATP splitting during the process of muscle relaxation. ATP is used in a process involving the transfer of the phosphoryl group to the Ca²⁺-ATPase with subsequent breakdown of the phosphorylated enzyme. The mechanism by which the Ca²⁺ pumping is associated with ATP hydrolysis is not fully understood in clear molecular terms and is usually summarized by a cycle of sequential reaction steps with two major states of the enzyme, E1 and E2, with high and low affinity for Ca²⁺ and ATP, respectively. Initially it was thought that vanadate affected this Ca²⁺ pump in the same way as other P-type ATPases, but recent studies show the existence of Ca²⁺ ATPases with different sensitivities to vanadate. It was demonstrated that some of the interactions, e.g. decameric species, disrupt the energetic coupling and the enzyme turnover. Other interactions of vanadium, e.g. monomeric species, may be without effect or even improve the coupling of Ca²⁺ pumping (Aureliano e Madeira, 1998; Aureliano, 2000).

3) Oxidative stress studies induced by cadmium, zinc, selenium, copper and vanadium are also almost limited to hepatic and renal injury studies. On other hand, the contribution of vanadate oligomers to vanadium toxicity is usually not considered. The different responses obtained on in vivo and in vitro studies proves that in vivo metals metabolism is very complex and great care must be taken on extrapolation from in vitro conditions. Recently, it was demonstrated that decameric vanadate species are responsible for a strong increase on lipid peroxidation and a decrease in cytosolic catalase activity thus contributing to oxidative stress responses upon vanadate intoxication. Furthermore, acute exposure studies suggest a different in vivo metabolic pattern for decameric vanadate species, pointing out the importance of vanadate speciation on the evaluation of vanadium toxicity (Aureliano et al., 2002; Soares et al, 2003).

Recent articles

M. Aureliano, V.M.C. Madeira (1998) in: J.O Nriagu (Ed.), Vanadium in the Environment, part 1: Chemistry and Biochemistry, J.Wiley, New York, 1998, chapter. 14, pp 333-357.

M. Aureliano (2000) “Vanadate oligomers inhibition of passive and active Ca²⁺ translocation by the Ca²⁺ pump of sarcoplasmic reticulum” J. Inorg. Biochem. 80: 145-147.

Teresa Tiago, Manuel Aureliano, Carlos Gutiérrez-Merino (2002) “Quenching of myosin intrinsic fluorescence unravels the existence of a high affinity binding site for decavanadate” J. Fluorescence, 12: 87-90.

M. Aureliano, N. Joaquim, A. Sousa, H. Martins, J.M Coucelo (2002) Oxidative stress in toadisfh (Halobactrachus didactylus) cardiac muscle: Acute exposure to vanadate oligomers” J. Inorg. Biochem. 90: 159-165.

T. Tiago, M. Aureliano, R.O.Duarte, J.J.G. Moura (2002) “Vanadate oligomers interaction with phosporylated myosin” Inorg. Chim. Acta 339: 317-321.

S.S. Soares, M. Aureliano*, N. Joaquim, J.M. Coucelo (2003) “Cadmium and vanadate oligomers effects on methaemoglobin reductase activity from Lusitanian toadfish”: J. Inorg. Biochem 94: 285-290.

link to :Bioquímica da FCT da Ualg: http://www.fct.ualg.pt/bioquimica