Effect Of Nacl On The Conformational Stability Of The Thermophilic Gamma-Glutamyltranspeptidase From Geobacillus Thermodenitrificans: Implication For Globular Protein Halotolerance
Effect Of Nacl On The Conformational Stability Of The Thermophilic Gamma-Glutamyltranspeptidase From Geobacillus Thermodenitrificans: Implication For Globular Protein Halotolerance(556 views) Pica A, Russo Krauss I, Castellano I, La Cara F, Graziano G, Sica F, Merlino A
Keywords: Circular Dichroism, Fluorescence, Gamma-Glutamyl Transferase, Gamma-Glutamyl Transpeptidase, Nacl, Protein Stabilization, Acrylamide, Gamma Glutamyltransferase, Globular Protein, Sodium Chloride, Solvent, Tryptophan, Amino Acid Sequence, Article, Conformation, Denaturation, Geobacillus, Nonhuman, Priority Journal, Protein Family, Protein Unfolding, Salt Tolerance, Temperature, Thermodynamics, Bacterial Proteins, Enzyme Stability, Gamma-Glutamyltransferase, Protein Structure, Secondary, Geobacillus Thermodenitrificans,
Affiliations: *** IBB - CNR ***
Department of Chemical Sciences, Università di Napoli Federico II, Complesso di Monte S. Angelo, Via Cinthia, I-80126 Napoli, Italy
Institute of Protein Biochemistry, CNR, Naples, Italy
Dipartimento di Scienze per la Biologia, la Geologia e l'Ambiente, Università Del Sannio, Benevento, Italy
Istituto di Biostrutture e Bioimmagini, CNR, Naples, Italy
References: Not available.
Effect Of Nacl On The Conformational Stability Of The Thermophilic Gamma-Glutamyltranspeptidase From Geobacillus Thermodenitrificans: Implication For Globular Protein Halotolerance
The transpeptidation activity of gamma-glutamyltranspeptidase from Geobacillus thermodenitrificans (GthGT) is negligible and the enzyme is highly thermostable. Here we have examined the effect of concentrated NaCl solutions on structure, stability, dynamics and enzymatic activity of GthGT. The protein exhibited hydrolytic activity over a broad range of NaCl concentrations. Even at 4. 0 M NaCl, GthGT retained more than 90% of the initial activity and showed unaltered fluorescence emission, secondary structure and acrylamide quenching on tryptophan fluorescence. Furthermore, at 2. 8 M and 4. 0 M NaCl the temperature-induced unfolding profiles are dramatically changed with large (>20 degrees C) positive shifts in the denaturation temperature. These features make GthGT an ideal system to be used in industrial processes that require high temperatures and high-salt environments. A general explanation of the NaCl effect by means of a statistical thermodynamic model is also provided, together with an analysis of residue distribution between protein surface and interior in 15 non-redundant families of halophilic and non-halophilic proteins. The results are in line with a comparative sequence and structural analysis between halophilic and non-halophilic gamma-glutamyltranspeptidases which revealed that a major role in halotolerance should be played by solvent exposed negatively charged residues. (C) 2012 Elsevier B. V. All rights reserved
Effect Of Nacl On The Conformational Stability Of The Thermophilic Gamma-Glutamyltranspeptidase From Geobacillus Thermodenitrificans: Implication For Globular Protein Halotolerance
Effect Of Nacl On The Conformational Stability Of The Thermophilic Gamma-Glutamyltranspeptidase From Geobacillus Thermodenitrificans: Implication For Globular Protein Halotolerance