Estabilidad catalítica del dominio de unión a ATP de una ATPasa transportadora de Cu(I) del arquea hipertermófila archaeoglobus fulgidus
Stability and catalytic activity of the ATP binding domain of a Cu (I) transport ATPasa from the hyperthermophile archaeal Archaeoglobus fulgidus (Af. CopA). This work aims to establish conditions for the isolated catalytic domain of Af. CopA to catalyze the hydrolysis of ATP and p-nitrophenyl-phosp...
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| Formato: | Tesis doctoral acceptedVersion |
| Lenguaje: | Español |
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Facultad de Farmacia y Bioquímica
2018
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| Acceso en línea: | http://repositoriouba.sisbi.uba.ar/gsdl/cgi-bin/library.cgi?a=d&c=posgraafa&cl=CL1&d=HWA_2664 http://repositoriouba.sisbi.uba.ar/gsdl/collect/posgraafa/index/assoc/HWA_2664.dir/2664.PDF |
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| Sumario: | Stability and catalytic activity of the ATP binding domain of a Cu (I) transport ATPasa from the hyperthermophile archaeal Archaeoglobus fulgidus (Af. CopA). This work aims to establish conditions for the isolated catalytic domain of Af. CopA to catalyze the hydrolysis of ATP and p-nitrophenyl-phosphate. Both activities are modulated by substrates, temperature, pH, Mg+2 y and ionic strength. Mg+2 is an essential activator of both activities. ATP-PN thermal stability was evaluated through the determination of his ATPase activity and structure. We found a high thermal stability at elevated temperatures and suggest at least two intermediaries with considerable amounts of secondary structure and the absence of it in the final thermal inactivation product. ATP-PN unfolding and refolding induced by urea was studied with different spectroscopic techniques, showing a reversible mechanism with at least one reaction intermediary in rapid equilibrium with his native state. ATP-PN net stability was found lower than the usually observed values for mesophilic proteins of similar molecular weight at 25 C. A possible thermal adaptation mechanism involved in ATP-PN is suggested based on his high amounts of secondary structure in his unfolded state, which could explain the lower values of H, S and Cp in contrasts to frequently observed values in mesophilic proteins of similar molecular weight. |
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