Data/hora: 24/06/2024 15:39:15

Biblioteca(s): 	Embrapa Agricultura Digital.	
Data corrente: 	26/01/2012	
Data da última atualização: 	24/01/2020	
Autoria: 	DUARTE, F.; SEPULVEDA, R.; ARAYA, R.; FLORES, S.; PEREZ-ACLE, T.; GONZALES, W.; GONZALES, D.; NESHICH, G.; NESHICH, I.; MAZONI, I.; HOLMES, D. S.	
Afiliação: 	FRANCISCO DUARTE, Universidad Andres Bello; RENE SEPULVEDA, Universidad Andres Bello; RAUL ARAYA, Universidad de Chile; SEBASTIAN FLORES, Universidad de Chile; TOMAS PEREZ-ACLE, Universidad de Chile; WENDY GONZALES, Universidad de Talca; DANILO GONZALES, Universidad de Talca; GORAN NESHICH, CNPTIA; IZABELLA NESHICH, Embrapa, Unicamp; IVAN MAZONI, CNPTIA; DAVID S. HOLMES, Universidad Andres Bello.	
Título: 	Mechanisms of protein stabilization at very low pH.	
Ano de publicação: 	2011	
Fonte/Imprenta: 	In: INTERNATIONAL BIOHYDROMETALLURGY SYMPOSIUM, 19.; 2011, Changsha, China. Biohydrometallurgy: biotech key to unlock mineral resources value: proceedings. Changsha: Central South University Press, 2011.	
Volume: 	v. 1.	
Descrição Física: 	IBS 2011.	
Idioma: 	Inglês	
Conteúdo: 	Physicochemical properties of periplasmic loops exposed to low pH were determined for two membrane proteins from the bioleaching-proteobacterium Acidithiobacillus ferrooxidans. The selected proteins were an aquaporin and a potassium (K+) channel and the properties evaluated were surface area hydrophobicity and amino acid composition. Properties were mapped onto three dimensional protein models and subjected to Accessible Surface Area (ASA) analysis and Molecular Dynamics (MD) simulations. Results were compared to equivalent loops from homologous proteins derived from microorganisms that live in neutral pH environments. It was found that periplasmic loops of both the aquaporin and the K+ channel protein of At ferrooxidans have less surface area and exhibit greater hydrophobicity compared to their neutrophilic homologs. A reduction of the percentage of amino acids that are negatively charged (aspartic and glutamic acid) and an increase in the percentage of positively charged amino acids (histidine, arginine and lysine) was also observed in the periplasmic loops of the aquaporin and potassium (K+) channel of At ferrooxidans. Finally, an increase in the proline content of the loops of At ferrooxidans was detected. Hypotheses for how these features could help stabilize the structure and function of proteins in extremely acidic condition are presented. It is noted that these proposed mechanisms are similar to those shown to be operational for the stabilization of thermophilic proteins. The data and hypotheses presented could help provide a theoretical foundation for designing proteins with improved molecular functions for bioleaching and acid mine drainage remediation. It is also valuable information for understanding the molecular underpinnings and evolution of protein function at low pH.	
Palavras-Chave: 	Aquaporinas; Canal de potássio; Estabilização de proteínas a pH baixo.	
Thesaurus Nal: 	Acidithiobacillus ferrooxidans; Aquaporins; Potassium channels; Proteins.	
Categoria do assunto: 	S Ciências Biológicas	
Registro original: 	Embrapa Agricultura Digital (CNPTIA)	
Exemplares: 	CNPTIA - (16409-1) - UPC - AA - DD -  -  -  - DIS