Galina G Zhadan

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Detailed differential scanning calorimetry (DSC), steady-state tryptophan fluorescence and far-UV and visible CD studies, together with enzymatic assays, were carried out to monitor the thermal denaturation of horseradish peroxidase isoenzyme c (HRPc) at pH 3.0. The spectral parameters were complementary to the highly sensitive but integral method of DSC.(More)
A differential-scanning-calorimetric study of the thermal denaturation of a sea-anemone (Radianthus macrodactylus) 8 kDa cytolytic toxin was carried out. The calorimetric traces were found to be irreversible and scan-rate-dependent under the experimental conditions employed. Scan-rate-dependent thermograms were explained in terms of a two-state kinetic(More)
Familial amyloidotic polyneuropathy (FAP) is an autosomal dominant hereditary type of amyloidosis involving amino acid substitutions in transthyretin (TTR). V30M-TTR is the most frequent variant, and L55P-TTR is the variant associated with the most aggressive form of FAP. The thermal stability of the wild-type, V30M-TTR, L55P-TTR and a non-amyloidogenic(More)
In a continuation of our earlier study [Ruiz-Arribas, A., Santamaría, R.I., Zhadan, G. G., Villar, E. & Shnyrov, V. L. (1994) Differential scanning calorimetric study of the thermal stability of xylanase from Streptomyces halstedii JM8, Biochemistry 33, 13787-13791], we used high-sensitivity differential scanning microcalorimetry, intrinsic tryptophan(More)
The kinetics of the structural changes affecting cardosin A, a plant aspartic proteinase (AP) from Cynara cardunculus L., in the presence of a mixture of acetonitrile (AN) in water (W) was studied. Incubation of cardosin A with 10% (v/v) AN resulted in a gradual increase in protein helicity, accompanied by changes in the tertiary structure, seen by changes(More)
The structural stability of a peroxidase, a dimeric protein from palm tree Chamaerops excelsa leaves (CEP), has been characterized by high-sensitivity differential scanning calorimetry, circular dichroism and steady-state tryptophan fluorescence at pH 3. The thermally induced denaturation of CEP at this pH value is irreversible and strongly dependent upon(More)
Thermal denaturation of acid-soluble collagen from polar cod (Eleginus gracialis) skin has been studied by scanning microcalorimetry and intrinsic spectrofluorimetry methods. The thermal denaturation process occurs in three independent stages reflecting the melting of 33 kDa, 97 kDa, and 230 kDa domains. Thermodynamical parameters of the collagen(More)
High-sensitivity differential scanning calorimetry has been applied to characterize the irreversible thermal denaturation of a cellulase, assuming that thermal denaturation takes place according to the kinetic scheme N-k-->D, where k is a first-order kinetic constant that changes with temperature, as given by the Arrhenius equation; N the native state, and(More)
The thermal stability of two xylanases with molecular masses of 45 (Xys1L) and 35 (Xys1S) kDa has been characterized thermodynamically by high-sensitivity scanning microcalorimetry in the pH range 3.0-9.0. Thermal denaturation of Xys1L reveals three thermodynamically independent domains, and that of Xys1S, which is a proteolytic fragment of Xys1L (without a(More)
The thermal stability of peroxidase from leaves of the African oil palm tree Elaeis guineensis (AOPTP) at pH 3.0 was studied by differential scanning calorimetry (DSC), intrinsic fluorescence, CD and enzymatic assays. The spectral parameters as monitored by ellipticity changes in the far-UV CD spectrum of the enzyme as well as the increase in tryptophan(More)