A5048480217- Enzyme Structure and Function
- Carbohydrate Chemistry and Synthesis
- Protein Structure and Dynamics
- Photosynthetic Processes and Mechanisms
- Ion Channels and Receptors
- Neurobiology and Insect Physiology Research
- Ion channel regulation and function
- Enzyme Production and Characterization
- Glycosylation and Glycoproteins Research
- Spectroscopy and Quantum Chemical Studies
- Phytochemicals and Antioxidant Activities
- Biochemical and Molecular Research
- Ion Transport and Channel Regulation
- Lysosomal Storage Disorders Research
- Studies on Chitinases and Chitosanases
- DNA Repair Mechanisms
- Polyamine Metabolism and Applications
- ATP Synthase and ATPases Research
- Bacterial Genetics and Biotechnology
- Chemical Reactions and Isotopes
- Protein Interaction Studies and Fluorescence Analysis
- Folate and B Vitamins Research
- Enzyme Catalysis and Immobilization
- Nitrogen and Sulfur Effects on Brassica
- Neonatal Health and Biochemistry
Larkin University
2018-2024
Florida International University
2020-2024
Charles University
1999-2021
Czech Academy of Sciences
2011-2020
Czech Academy of Sciences, Institute of Microbiology
2015-2020
University of South Bohemia in České Budějovice
2008-2017
Nova Southeastern University
2017
Czech Academy of Sciences, Global Change Research Institute
2012-2015
Johannes Kepler University of Linz
2014
Institut de Neurobiologie de la Méditerranée
2009
The vanilloid receptor [transient potential (TRP)V1, also known as VR1] is a member of the TRP channel family. These receptors share significant sequence homology, similar predicted structure with six transmembrane-spanning domains (S1–S6), pore-forming region between S5 and S6, cytoplasmically oriented C- N-terminal regions. Although structural/functional studies have identified some key amino acids influencing gating TRPV1 ion channel, possible contributions terminal regions to function...
Mutations targeting as few four residues lining the access tunnel extended half-life of an enzyme in 40 % dimethyl sulfoxide from minutes to weeks and increased its melting temperature by 19 °C. Protein crystallography molecular dynamics revealed that residue packing is a key determinant protein stability active-site accessibility for cosolvent molecules (red dots).
Cholesterol suppresses the activity of a channel needed to refill intracellular calcium stores.
Characterization of disease-associated Orai1 mutants reveals the multistep gating mechanism for CRAC channel.
The Ca(2+) release-activated channel mediates influx in a plethora of cell types, thereby controlling diverse cellular functions. complex is composed stromal interaction molecule 1 (STIM1), an endoplasmic reticulum Ca(2+)-sensing protein, and Orai1, plasma membrane channel. Channels STIM1 Orai1 mediate even at low extracellular concentrations. We investigated whether the activity adapted to different environmental used homology modeling molecular dynamics simulations predict presence...
The transient receptor potential vanilloid receptor-1 (TRPV1) is a sensory neuron-specific nonselective cation channel that gated in response to various noxious stimuli: pungent vanilloids, low pH, heat, and depolarizing voltages. By its analogy K + channels, the S6 inner helix domain of TRPV1 (Y666-G683) prime candidate form most constricted region permeation pathway might therefore encompass an as-yet-unmapped gate channel. Using alanine-scanning mutagenesis, we identified 16 17 residues,...
Disease-associated mutations in the Ca 2+ sensor STIM1 alter its conformation and disrupt ion binding.
Abstract The use of enzymes for biocatalysis can be significantly enhanced by using organic cosolvents in the reaction mixtures. Selection cosolvent type and concentration range an enzymatic is challenging requires extensive empirical testing. An understanding protein–solvent interaction could provide a theoretical framework rationalising selection process. Here, behaviour three model (haloalkane dehalogenases) was investigated presence representative (acetone, formamide, isopropanol)....
The crystal structure of the flavodoxin-like protein WrbA with oxidized FMN bound reveals a close relationship to mammalian NAD(P)H:quinone oxidoreductase, Nqo1. Structural comparison WrbA, flavodoxin, and Nqo1 indicates how twisted open-sheet fold flavodoxins is elaborated form multimers that extend catalytic function from one-electron transfer between partners using two-electron reduction xenobiotics FAD. suggests novel physiological role for
The ankyrin transient receptor potential channel TRPA1 is a non-selective cationic that expressed by sensory neurons, where it can be activated pungent chemicals, such as AITC (allyl isothiocyanate), cinnamon or allicin, deep cooling (<18 °C) highly depolarizing voltages (>+100 mV). From the cytoplasmic side, this regulated negatively charged ligands phosphoinositides inorganic polyphosphates, most likely through an interaction with yet unidentified positively domain(s). In present study, we...
Fungal β‐ N ‐acetylhexosaminidases are inducible extracellular enzymes with many biotechnological applications. The enzyme from Penicillium oxalicum has unique enzymatic properties despite its close evolutionary relationship other fungal hexosaminidases. It high GalNAcase activity, tolerates substrates the modified N‐acyl group better and some unusual catalytic properties. In order to understand these features, we performed isolation, biochemical enzymological characterization, molecular...
Abstract Background Nitrilases attract increasing attention due to their utility in the mild hydrolysis of nitriles. According activity and gene screening, filamentous fungi are a rich source nitrilases distinct evolution from widely examined bacterial counterparts. However, fungal have been less explored than ones. typically heterogeneous quaternary structures, forming short spirals extended filaments, these features making structural studies difficult. Results A nitrilase was amplified by...
Abstract This work is a structure‐activity relationship study that investigates the influence of nature and amount negative charge in carbohydrate substrates on affinity β‐ N ‐acetylhexosaminidases, stimulation natural killer cells. It describes synthetic procedures yielding novel glycosides are useful immunoactivation. Specifically, we present thorough ability six C‐6 modified ‐acetylhexosaminides (aldehyde, uronate, 6‐ O ‐sulfate, ‐phosphate) to serve as for cleavage glycosylation by...
The initial activation step in the gating of ubiquitously expressed Orai1 calcium (Ca
β-N-Acetylhexosaminidases feature so-called wobbling specificity, which means that they cleave substrates both in gluco- and galacto- configurations, with the activity ratio depending on enzyme source. Here we present new finding fungal β-N-acetylhexosaminidases are able to hydrolyze transfer 4-deoxy-N-acetylhexosaminides high yields. This clearly demonstrates 4-hydroxy moiety at substrate pyranose ring is not essential for binding active site, was also confirmed by molecular docking of...
Charybdotoxin, belonging to the group of so-called scorpion toxins, is a short peptide able block many voltage-gated potassium channels, such as mKv1.3, with high affinity. We use reliable homology model based on high-resolution crystal structure 94% sequence identical homologue Kv1.2 for charybdotoxin docking followed by molecular dynamics simulations investigate mechanism and energetics unbinding, tracing behavior channel protein during umbrella-sampling moved away from binding site. The...