Ivan Maslov

University of Groningen | RUG · Membrane Enzymology Group

The primary role of telomerase is the lengthening of telomeres. Nonetheless, emerging evidence highlights additional functions of telomerase outside of the nucleus. Specifically, its catalytic subunit, TERT (Telomerase Reverse Transcriptase), is detected in the cytosol and mitochondria. Several studies have suggested an elevation in TERT concentrat...

Solvatochromic compounds have emerged as valuable environment-sensitive probes for biological research. Here we used thiol-reactive solvatochromic analogs of the green fluorescent protein (GFP) chromophore to track conformational changes in two proteins, recoverin and the A2A adenosine receptor (A2AAR). Two dyes showed Ca2+-induced fluorescence cha...

Protein diffusion is a critical factor governing the functioning and organization of a cell’s cytoplasm. In this study, we investigate the influence of (poly)ribosome distribution, cell aging, protein aggregation, and biomolecular condensate formation on protein mobility within the E. coli cytoplasm. We employ nanoscale single-molecule displacement...

Microbial rhodopsins are retinal membrane proteins that found a broad application in optogenetics. The oligomeric state of rhodopsins is important for their functionality and stability. Of particular interest is the oligomeric state in the cellular native membrane environment. Fluorescence microscopy provides powerful tools to determine the oligome...

Cytochromes P450 (CYP) are a family of membrane proteins involved in the production of endogenous molecules and the metabolism of xenobiotics. It is well-known that the composition of the membrane can influence the activity and orientation of CYP proteins. However, little is known about how membrane composition affects the ligand binding properties...

Microbial rhodopsins are retinal membrane proteins that found a broad application in optogenetics. The oligomeric state of rhodopsins is important for their functionality and stability. Of particular interest is the oligomeric state in the cellular native membrane environment. Fluorescence microscopy provides powerful tools to determine the oligome...

Solvatochromic compounds have emerged as valuable environment-sensitive probes for biological research, with the chromophore of the green fluorescent protein (GFP) being a well-studied example. In this study, we demonstrate that synthetic analogues of the GFP chromophore can be used to investigate ligand-induced conformational changes in proteins....

Microbial rhodopsins are retinal membrane proteins that found a broad application in optogenetics. The oligomeric state of rhodopsins is important for their functionality and stability. Of particular interest is the oligomeric state in the cellular native membrane environment. Fluorescence microscopy provides powerful tools to determine the oligome...

G protein-coupled receptors (GPCRs) represent an important class of drug targets, and their structural studies facilitate rational drug discovery. However, atomic structures of only about 20% of human GPCRs have been solved to date. Recombinant production of GPCRs for structural studies at a large scale is challenging due to their low expression le...

The complex pharmacology of G-protein-coupled receptors (GPCRs) is defined by their multi-state conformational dynamics. Single-molecule Förster Resonance Energy Transfer (smFRET) is well suited to quantify dynamics for individual protein molecules; however, its application to GPCRs is challenging. Therefore, smFRET has been limited to studies of i...

Single-molecule fluorescence spectroscopy and molecular dynamics simulations illuminate the structure and dynamics of PSD-95, a protein involved in neural plasticity.

Flavin-based fluorescent proteins (FbFPs) are small fluorescent proteins derived from light-oxygen-voltage (LOV) domains. The proteins bind ubiquitous endogenous flavins as chromophores and can be used as versatile in vivo reporter proteins under aerobic and anaerobic conditions. This chapter presents the methodology to identify LOV domain sequence...

Mitochondria play a critical role in providing energy, maintaining cellular metabolism, and regulating cell survival and death. To carry out these crucial functions, mitochondria employ more than 1500 proteins, distributed between two membranes and two aqueous compartments. An extensive network of dedicated proteins is engaged in importing and sort...

Mitochondrial protein biogenesis relies almost exclusively on the expression of nuclear-encoded polypeptides. The current model postulates that most of these proteins have to be delivered to their final mitochondrial destination after their synthesis in the cytoplasm. However, the knowledge of this process remains limited due to the absence of prop...

Background: Recoverin is a 23 kDa protein, belonging to the superfamily of EF-hand Ca2+-binding proteins. One of the functions of recoverin is to regulate the activity of the rhodopsin kinase GRK1, which regulates the activity of rhodopsin. In dim ambient light, the level of calcium in the rod cells of the retina is high, so recoverin binds to and...

Background: Recoverin is a calcium sensor membrane-associated protein that inhibits rhodopsin kinase thereby participating in the regulation of visual transduction. Here we examined calcium-induced conformational changes in recoverin conjugated with fluorescent dye Alexa647. Methods: Photophysical properties of immobilized and freely diffusing reco...

Recoverin is a calcium-binding protein expressed in the retina; it plays an important role in the adaptation of vision to background light. Binding of recoverin to calcium ions induces large conformational changes, including the release of myristoyl group post-translationally attached to the protein from the protein cavity towards the solution. It...

Protein-fragment complementation assays are used ubiquitously for probing protein–protein interactions. Most commonly, the reporter protein is split in two parts, which are then fused to the proteins of interest and can reassemble and provide a readout if the proteins of interest interact with each other. The currently known split fluorescent prote...

Mycobacterium tuberculosis (Mtb) infection is among top ten causes of death worldwide, and the number of drug-resistant strains is increasing. The direct interception of human immune signaling molecules by Mtb remains elusive, limiting drug discovery. Oxysterols and secosteroids regulate both innate and adaptive immune responses. Here we report a f...

The complex pharmacology of G-protein-coupled receptors (GPCRs) is defined by their multi-state conformational dynamics. Single-molecule Förster Resonance Energy Transfer (smFRET) is well-suited to quantify dynamics for individual protein molecules, however, its application to GPCRs is challenging; therefore, smFRET has been limited to studies of i...

Mitochondrial protein biogenesis relies almost exclusively on the expression of nuclear-encoded polypeptides. The current model postulates that most of these proteins have to be delivered to their final mitochondrial destination after their synthesis in the cytoplasm. However, the knowledge of this process remains limited due to the absence of prop...

Purpose: Reducing the undesirable systemic effect of photodynamic therapy (PDT) can be achieved by incorporating a photosensitizer in microparticles (MPs). This study is devoted to the preparation of biocompatible biodegradable MPs with the inclusion of the natural photosensitizer Radachlorin (RС) and an assessment of the possibility of their use f...

G protein-coupled receptors (GPCRs) constitute the largest superfamily of membrane proteins that are involved in regulation of sensory and physiological processes and implicated in many diseases. The last decade revolutionized the GPCR field by unraveling multiple high-resolution structures of many different receptors in complexes with various liga...

Mycobacterium tuberculosis (Mtb) infection is among top ten causes of death worldwide, and the number of drug-resistant strains is increasing. The direct interception of human immune signaling molecules by Mtb remains elusive, limiting drug discovery. Oxysterols and secosteroids regulate both innate and adaptive immune responses. Here we report a f...

Research on halophilic microorganisms is important due to their relation to fundamental questions of survival of living organisms in a hostile environment. Here we introduce a novel method to stain halophiles with MitoTracker fluorescent dyes in their growth medium. The method is based on membrane-potential sensitive dyes, which were originally use...

We model the deformation that a meteorite can undergo during its passage through the atmosphere. First, the pressure distribution around a solid body in a flow was measured in a wind tunnel. Second, the deformation of molten tin droplets with different temperatures dropped into water was observed. Finally, a mathematical model of the fall was const...