Biomaterial Database

[Study on secondary structure and properties of alpha- and gamma-forms of human thrombin]. 2006

L P Shvachko, and S V Litvinovich, and V K Kibirev

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.

UI	MeSH Term	Description	Entries
D008024	Ligands	A molecule that binds to another molecule, used especially to refer to a small molecule that binds specifically to a larger molecule, e.g., an antigen binding to an antibody, a hormone or neurotransmitter binding to a receptor, or a substrate or allosteric effector binding to an enzyme. Ligands are also molecules that donate or accept a pair of electrons to form a coordinate covalent bond with the central metal atom of a coordination complex. (From Dorland, 27th ed)	Ligand
D011489	Protein Denaturation	Disruption of the non-covalent bonds and/or disulfide bonds responsible for maintaining the three-dimensional shape and activity of the native protein.	Denaturation, Protein,Denaturations, Protein,Protein Denaturations
D002152	Calorimetry, Differential Scanning	Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.	Differential Thermal Analysis, Calorimetric,Calorimetric Differential Thermal Analysis,Differential Scanning Calorimetry,Scanning Calorimetry, Differential
D002942	Circular Dichroism	A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)	Circular Dichroism, Vibrational,Dichroism, Circular,Vibrational Circular Dichroism
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D013696	Temperature	The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.	Temperatures
D013816	Thermodynamics	A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)	Thermodynamic
D013917	Thrombin	An enzyme formed from PROTHROMBIN that converts FIBRINOGEN to FIBRIN.	Thrombase,Thrombin JMI,Thrombin-JMI,Thrombinar,Thrombostat,alpha-Thrombin,beta,gamma-Thrombin,beta-Thrombin,gamma-Thrombin,JMI, Thrombin
D017433	Protein Structure, Secondary	The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to ALPHA-HELICES; BETA-STRANDS (which align to form BETA-SHEETS), or other types of coils. This is the first folding level of protein conformation.	Secondary Protein Structure,Protein Structures, Secondary,Secondary Protein Structures,Structure, Secondary Protein,Structures, Secondary Protein
D020033	Protein Isoforms	Different forms of a protein that may be produced from different GENES, or from the same gene by ALTERNATIVE SPLICING.	Isoform,Isoforms,Protein Isoform,Protein Splice Variant,Splice Variants, Protein,Protein Splice Variants,Isoform, Protein,Isoforms, Protein,Splice Variant, Protein,Variant, Protein Splice,Variants, Protein Splice