Institute of Biotechnology CAS
Institute of Biotechnology CAS
Dostalova P.,Institute of Biotechnology CAS |
Zatecka E.,Institute of Biotechnology CAS |
Dvorakova-Hortova K.,Institute of Biotechnology CAS |
Dvorakova-Hortova K.,Charles University
International Journal of Molecular Sciences | Year: 2017
The crucial role that oestrogens play in male reproduction has been generally accepted; however, the exact mechanism of their action is not entirely clear and there is still much more to be clarified. The oestrogen response is mediated through oestrogen receptors, as well as classical oestrogen receptors’ variants, and their specific co-expression plays a critical role. The importance of oestrogen signalling in male fertility is indicated by the adverse effects of selected oestrogen-like compounds, and their interaction with oestrogen receptors was proven to cause pathologies. The aims of this review are to summarise the current knowledge on oestrogen signalling during spermatogenesis and sperm maturation and discuss the available information on oestrogen receptors and their splice variants. An overview is given of species-specific differences including in humans, along with a detailed summary of the methodology outcome, including all the genetically manipulated models available to date. This review provides coherent information on the recently discovered mechanisms of oestrogens’ and oestrogen receptors’ effects and action in both testicular somatic and germ cells, as well as in mature sperm, available for mammals, including humans. © 2017 by the authors. Licensee MDPI, Basel, Switzerland.
Bohuslavova R.,Institute of Biotechnology CAS |
Cerychova R.,Institute of Biotechnology CAS |
Cerychova R.,Charles University |
Nepomucka K.,Institute of Biotechnology CAS |
Pavlinkova G.,Institute of Biotechnology CAS
BMC Endocrine Disorders | Year: 2017
Background: Hypoxia inducible factor 1 (HIF-1) activates protective pathways to counteract hypoxia and prevent tissue damage in conjunction with renal injury. The aim of this study was to evaluate a role of HIF-1 in diabetes-induced kidney damage. Methods: We used a streptozotocin-induced diabetes mouse model and compared biochemical, histological and molecular parameters associated with kidney damage in Hif1α deficient (Hif1α +/-) and wild-type mice. Results: We showed that Hif1α deficiency accelerated pathological changes in the early stage of DN. Six weeks after diabetes-induction, Hif1α deficient mice showed more prominent changes in biochemical serum parameters associated with glomerular injury, increased expression of podocyte damage markers, and loss of podocytes compared to wild-type mice. These results indicate that Hif1α deficiency specifically affects podocyte survival in the early phase of DN, resulting in diabetic glomerular injury. In contrast, renal fibrosis was not affected by the global reduction of Hif1α, at least not in the early phase of diabetic exposure. Conclusions: Together our data reveal that HIF-1 has an essential role in the early response to prevent diabetes-induced tissue damage and that impaired HIF-1 signaling results in a faster progression of DN. Although the modulation of HIF-1 activity is a high-priority target for clinical treatments, further study is required to investigate HIF-1 as a potential therapeutic target for the treatment of DN. © 2017 The Author(s).
Cerny J.,Institute of Biotechnology CAS |
Schneider B.,Institute of Biotechnology CAS |
Biedermannova L.,Institute of Biotechnology CAS
Physical Chemistry Chemical Physics | Year: 2017
Water molecules represent an integral part of proteins and a key determinant of protein structure, dynamics and function. WatAA is a newly developed, web-based atlas of amino-acid hydration in proteins. The atlas provides information about the ordered first hydration shell of the most populated amino-acid conformers in proteins. The data presented in the atlas are drawn from two sources: experimental data and ab initio quantum-mechanics calculations. The experimental part is based on a data-mining study of a large set of high-resolution protein crystal structures. The crystal-derived data include 3D maps of water distribution around amino-acids and probability of occurrence of each of the identified hydration sites. The quantum mechanics calculations validate and extend this primary description by optimizing the water position for each hydration site, by providing hydrogen atom positions and by quantifying the interaction energy that stabilizes the water molecule at the particular hydration site position. The calculations show that the majority of experimentally derived hydration sites are positioned near local energy minima for water, and the calculated interaction energies help to assess the preference of water for the individual hydration sites. We propose that the atlas can be used to validate water placement in electron density maps in crystallographic refinement, to locate water molecules mediating protein-ligand interactions in drug design, and to prepare and evaluate molecular dynamics simulations. WatAA: Atlas of Protein Hydration is freely available without login at www.dnatco.org/WatAA. © 2017 the Owner Societies.
PubMed | University Of Je Purkinje, CAS Institute of Microbiology, Institute of Biotechnology CAS, Czech Institute of Chemical Process Fundamentals and Leibniz Institute of Polymer Research
Type: Journal Article | Journal: Macromolecular bioscience | Year: 2016
For the design of a biohybrid structure as a ligand-tailored drug delivery system (DDS), it is highly sophisticated to fabricate a DDS based on smoothly controllable conjugation steps. This article reports on the synthesis and the characterization of biohybrid conjugates based on noncovalent conjugation between a multivalent biotinylated and PEGylated poly(amido amine) (PAMAM) dendrimer and a tetrameric streptavidin-small protein binding scaffold. This protein binding scaffold (SA-ABDwt) possesses nM affinity toward human serum albumin (HSA). Thus, well-defined biohybrid structures, finalized by binding of one or two HSA molecules, are available at each conjugation step in a controlled molar ratio. Overall, these biohybrid assemblies can be used for (i) a controlled modification of dendrimers with the HSA molecules to increase their blood-circulation half-life and passive accumulation in tumor; (ii) rendering dendrimers a specific affinity to various ligands based on mutated ABD domain, thus replacing tedious dendrimer-antibody covalent coupling and purification procedures.
PubMed | Czech Institute of Macromolecular Chemical, Institute of Biotechnology CAS, Charles University and CAS Institute of Microbiology
Type: Journal Article | Journal: Acta crystallographica. Section F, Structural biology communications | Year: 2016
Nepenthesins are aspartic proteases secreted by carnivorous pitcher plants of the genus Nepenthes. They significantly differ in sequence from other plant aspartic proteases. This difference, which provides more cysteine residues in the structure of nepenthesins, may contribute to their unique stability profile. Recombinantly produced nepenthesin 1 (rNep1) from N. gracilis in complex with pepstatin A was crystallized under two different crystallization conditions using a newly formulated low-pH crystallization screen. The diffraction data were processed to 2.9 and 2.8 resolution, respectively. The crystals belonged to space group P212121, with unit-cell parameters a = 86.63, b = 95.90, c = 105.40, = = = 90 and a = 86.28, b = 97.22, c = 103.78, = = = 90, respectively. Matthews coefficient and solvent-content calculations suggest the presence of two molecules of rNep1 in the asymmetric unit. Here, the details of the crystallization experiment and analysis of the X-ray data are reported.
PubMed | Novozymes AS, Institute of Biotechnology CAS and Institute of Chemical Technology Prague
Type: Journal Article | Journal: PloS one | Year: 2016
The single-strand-specific S1 nuclease from Aspergillus oryzae is an archetypal enzyme of the S1-P1 family of nucleases with a widespread use for biochemical analyses of nucleic acids. We present the first X-ray structure of this nuclease along with a thorough analysis of the reaction and inhibition mechanisms and of its properties responsible for identification and binding of ligands. Seven structures of S1 nuclease, six of which are complexes with products and inhibitors, and characterization of catalytic properties of a wild type and mutants reveal unknown attributes of the S1-P1 family. The active site can bind phosphate, nucleosides, and nucleotides in several distinguished ways. The nucleoside binding site accepts bases in two binding modes-shallow and deep. It can also undergo remodeling and so adapt to different ligands. The amino acid residue Asp65 is critical for activity while Asn154 secures interaction with the sugar moiety, and Lys68 is involved in interactions with the phosphate and sugar moieties of ligands. An additional nucleobase binding site was identified on the surface, which explains the absence of the Tyr site known from P1 nuclease. For the first time ternary complexes with ligands enable modeling of ssDNA binding in the active site cleft. Interpretation of the results in the context of the whole S1-P1 nuclease family significantly broadens our knowledge regarding ligand interaction modes and the strategies of adjustment of the enzyme surface and binding sites to achieve particular specificity.
PubMed | Max Planck Institute of Molecular Cell Biology and Genetics and Institute of Biotechnology CAS
Type: Journal Article | Journal: Current biology : CB | Year: 2016
Microtubules nucleated from an organizing center grow radially in all directions. A new study shows that, to organize those microtubules into arrays of parallel bundles, the kinesin-14 Cik1-Kar3 guides growing microtubule tips along pre-existing microtubules.
Biedermannova L.,Institute of Biotechnology CAS |
Schneider B.,Institute of Biotechnology CAS
Biochimica et Biophysica Acta - General Subjects | Year: 2016
Background Most biological processes involve water, and the interactions of biomolecules with water affect their structure, function and dynamics. Scope of review This review summarizes the current knowledge of protein and nucleic acid interactions with water, with a special focus on the biomolecular hydration layer. Recent developments in both experimental and computational methods that can be applied to the study of hydration structure and dynamics are reviewed, including software tools for the prediction and characterization of hydration layer properties. Major conclusions In the last decade, important advances have been made in our understanding of the factors that determine how biomolecules and their aqueous environment influence each other. Both experimental and computational methods contributed to the gradually emerging consensus picture of biomolecular hydration. General significance An improved knowledge of the structural and thermodynamic properties of the hydration layer will enable a detailed understanding of the various biological processes in which it is involved, with implications for a wide range of applications, including protein-structure prediction and structure-based drug design. © 2016 Elsevier B.V. All rights reserved.
Biedermannova L.,Institute of Biotechnology CAS |
Schneider B.,Institute of Biotechnology CAS
Acta Crystallographica Section D: Biological Crystallography | Year: 2015
Crystallography provides unique information about the arrangement of water molecules near protein surfaces. Using a nonredundant set of 2818 protein crystal structures with a resolution of better than 1.8Å, the extent and structure of the hydration shell of all 20 standard amino-acid residues were analyzed as function of the residue conformation, secondary structure and solvent accessibility. The results show how hydration depends on the amino-acid conformation and the environment in which it occurs. After conformational clustering of individual residues, the density distribution of water molecules was compiled and the preferred hydration sites were determined as maxima in the pseudo-electron-density representation of water distributions. Many hydration sites interact with both main-chain and side-chain amino-acid atoms, and several occurrences of hydration sites with less canonical contacts, such as carbon-donor hydrogen bonds, OH-π interactions and off-plane interactions with aromatic heteroatoms, are also reported. Information about the location and relative importance of the empirically determined preferred hydration sites in proteins has applications in improving the current methods of hydration-site prediction in molecular replacement, ab initio protein structure prediction and the set-up of molecular-dynamics simulations. © 2015 International Union of Crystallography.
PubMed | Institute of Biotechnology CAS
Type: Journal Article | Journal: Nucleic acids research | Year: 2016
The web service DNATCO (dnatco.org) classifies local conformations of DNA molecules beyond their traditional sorting to A, B and Z DNA forms. DNATCO provides an interface to robust algorithms assigning conformation classes called NTC: to dinucleotides extracted from DNA-containing structures uploaded in PDB format version 3.1 or above. The assigned dinucleotide NTC: classes are further grouped into DNA structural alphabet NTA: , to the best of our knowledge the first DNA structural alphabet. The results are presented at two levels: in the form of user friendly visualization and analysis of the assignment, and in the form of a downloadable, more detailed table for further analysis offline. The website is free and open to all users and there is no login requirement.