Tetramerization of human guanylate-binding protein 1 is mediated by coiled-coil formation of the C-terminal α-helices.

The human guanylate-binding protein 1 (hGBP1) is a large GTP-binding protein belonging to the dynamin family, a common feature of which is nucleotide-dependent assembly to homotypic oligomers. Assembly leads to stimulation of GTPase activity, which, in the case of dynamin, is responsible for scission of vesicles from membranes. By yeast two-hybrid and biochemical experiments we addressed intermolecular interactions between all subdomains of hGBP1 and identified the C-terminal subdomain, α12/13, as a new interaction site for self-assembly.

Immobilization of biotinylated hGBP1 in a defined orientation on surfaces is crucial for uniform interaction with analyte proteins and catalytic activity.

Guanylate binding proteins (GBPs) belong to the dynamin superfamily of large GTP binding proteins. A biochemical feature common to these proteins is guanosine-triphosphate (GTP) binding leading to self-assembly of the proteins, and this in turn results in higher catalytic GTP hydrolysis activity. In the case of human guanylate binding protein 1 (hGBP1) homodimer formation is observed after binding of nonhydrolyzable GTP analogs like GppNHp.

Steering the enzymatic activity of proteins by ionic liquids. A case study of the enzyme kinetics of yeast alcohol dehydrogenase.

We explore ion-specific effects exerted by ionic liquids (ILs) on the enzyme kinetics of yeast alcohol dehydrogenase. The Michaelis-Menten reaction scheme is used to parameterize the observed kinetics in terms of the apparent dissociation constant of the substrate (Michaelis-Menten constant) K(M), the turnover number k(cat), which reflects the number of product molecules per enzyme molecule per second, and the enzymatic efficiency k(cat)/K(M) of the reaction. Results for fifteen salts are used to deduce Hofmeister anion and cation series.

Intracellular trafficking of guanylate-binding proteins is regulated by heterodimerization in a hierarchical manner.

Guanylate-binding proteins (GBPs) belong to the dynamin family of large GTPases and represent the major IFN-γ-induced proteins. Here we systematically investigated the mechanisms regulating the subcellular localization of GBPs. Three GBPs (GBP-1, GBP-2 and GBP-5) carry a C-terminal CaaX-prenylation signal, which is typical for small GTPases of the Ras family, and increases the membrane affinity of proteins.

Mechanism of GTPase-activity-induced self-assembly of human guanylate binding protein 1.

Human guanylate binding protein 1 (hGBP1) belongs to the dynamin superfamily of large GTPases (LGs). In the course of GTP hydrolysis, the protein undergoes structural changes leading to self-assembly of the protein, which is a characteristic property of all family members. For self-assembly, the protein employs two distinct interaction sites, one of which is located within the LG domain of the protein located at the N-terminus, and the second is located in the C-terminal alpha-helical domain.