Amino acid transport in thermophiles: Characterization of an arginine-binding protein from Thermotoga maritima. 3. Conformational dynamics and stability

作者：Ausili A^*; Pennacchio A; Staiano M; Dattelbaum J D; Fessas D; Schiraldi A; D' Auria S

来源：Journal of Photochemistry and Photobiology B: Biology , 2013, 118: 66-73.

DOI：10.1016/j.jphotobiol.2012.11.004

• Fluorescence
• Phosphorescence
• Arginine
• Extremophiles
• Unfolding
• Thermodynamics

Arginine-binding protein from Thermotoga maritima (TmArgBP) is a 27.7 kDa protein possessing the typical two domain structure of the periplasmic binding protein family. The protein is characterized by high specificity and affinity for binding a single molecule of L-arginine. %26lt;br%26gt;In this work, the effect of temperature and/or guanidine hydrochloride on structure and stability of the protein in the absence and in the presence of L-arginine has been investigated by differential scanning calorimetry, far-UV circular dichroism and intrinsic tryptophan phosphorescence and fluorescence. The results revealed that TmArgBP undergoes an irreversible one-step thermal unfolding process in a cooperative mode. The TmArgBP melting temperature was recorded at 115 degrees C. The presence of L-arginine did not change the protein secondary structure content as well as the intrinsic phosphorescence and fluorescence protein properties, even if it increases the structural stability of the protein. %26lt;br%26gt;The obtained results are discussed in combination with a detailed inspection of the three-dimensional structure of the protein.

• 出版日期2013-1-5