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[Study on secondary structure and properties of alpha- and gamma-forms of human thrombin].
- Source :
-
Ukrains'kyi biokhimichnyi zhurnal (1999 ) [Ukr Biokhim Zh (1999)] 2006 Jan-Feb; Vol. 78 (1), pp. 87-93. - Publication Year :
- 2006
-
Abstract
- Secondary structure and enzymatic properties of human a-thrombin and its gamma-form (obtaining during autolysis of the native enzyme) have been studied by differential scanning calorimetry (DSC) and circular dichroism (CD). According to DSC-data both alpha-thrombin and gamma-thrombin contained only one thermal transition peak at 58.5 and 53.3 degrees C, respectively. A comparison of these values suggested that gamma-form is less stable than initial a-thrombin. In contrast to that the thermogram of DIP-a-thrombin had two peaks (57.5 and 64.5 degrees C). CD spectra showed that conversion a- to gamma-thrombin influenced the secondary structure of the enzyme slightly. The study of the inhibitory effect of such polyanions as ATP and dextran sulfate (DS) upon thrombin-catalyzed cleavages of fibrinogen has shown that the growth of the negative charge of the polyanion molecule resulted in the increase of its inhibitory activity. The catalytically non-active DIP-alpha-thrombin, which retained the native anion-binding exosite 1, was shown to decrease the inhibitory power of the dextran sulfate. It was explained by competition of DS with the exosite 1 of both alpha- and DIP-alpha -thrombin. In contrast to that DIP-gamma-thrombin having exosite 1 destroyed neither competed nor influenced the anticoagulant capacity of dextran sulfate toward the native alpha-thrombin. In accordance with our data thrombin consists of two rather strong interacting domains. It was shown further that its anion-binding exosite 1 may play a significant role in the interaction of the enzyme with dextran sulfate.
Details
- Language :
- Russian
- Volume :
- 78
- Issue :
- 1
- Database :
- MEDLINE
- Journal :
- Ukrains'kyi biokhimichnyi zhurnal (1999 )
- Publication Type :
- Academic Journal
- Accession number :
- 17147270