Two-state irreversible thermal denaturation of anionic peanut (Arachis hypogaea L.) peroxidase

Calorimetric Study of Inulin as Cryo- and Lyoprotector of Bovine Plasma Proteins

“…It was found for all the saccharides that Td and H are scanning rate dependent. Td values increased 5  2 °C in all the samples with increasing scanning rate, similar behavior was reported in references [56][57][58]. Furthermore, the H decreased ( 10%) with increasing scanning rate that was in agreement with the results reported in references [21,59].…”

Stability and structural changes of horseradish peroxidase: Microwave versus conventional heating treatment

“…The fluorescence spectra acquired for non-treated HRP is characterized by a unique peak, at em (max) ∼327 nm, suggesting that the Trp117 is protected from the solvent [25]. The fluorescence emission intensity of untreated HRP was low, probably because the tryptophan fluorescence was quenched due to intramolecular Trp-heme energy transfer in native HRP [28,36].…”

“…The intrinsic fluorescence of HRP is greatly dependent on the fluorescence energy transfer from tryptophan to heme [21,27]. The far UV-CD (190-250 nm) and tryptophan fluorescence emission spectrum provide information about the secondary and tertiary structure of the protein [28].…”

Thermal stability of peroxidase from Chamaerops excelsa palm tree at pH 3

“…On comparing the kinetic parameters of CEP stability at pH 3 with those of other peroxidases [17,18,21,22], it is evident that the thermostability of CEP is substantially greater than that of horseradish peroxidase isoenzyme c (HRPc) and anionic peanut (Arachis hypogaea L.) peroxidase (aPrx), and is practically the same as the stability of peroxidase from the African oil palm tree Elaeis guineensis (AOPTP) and peroxidase from royal palm tree Roystonea regia (RPTP). Thus, the T m for CEP at a scan rate of 60 K h −1 is 70.1 ± 0.2 • C while for aPrx this value is 39.4 ± 0.2 • C; for HRPc it is 60.2 ± 0.2 • C; for AOPTP it is 72.3 ± 0.2 • C and for RPTP it is 72.3 ± 0.2 • C. In row of the Arrhenius energy of activation values CEP (105.1 ± 1.7 kcal mol −1 ) close to AOPTP (103 ± 6 kcal mol −1 ) being lower RPTP (129.1 ± 0.8 kcal mol −1 ) and significantly higher in comparison those of HRPc (38.2 ± 0.5 kcal mol −1 ) and aPrx (67.9 ± 0.5 kcal mol −1 ).…”

“…Calorimetry scans were performed on a MicroCal MC-2D differential scanning microcalorimeter (MicroCal Inc., Northampton, MA, USA) with cell volumes of 1.22 mL as described previously [18,21,22]. All solutions were degassed by stirring under a vacuum prior to scanning.…”