Proteasome Interactome and Its Role in the Mechanisms of Brain Plasticity.

Proteasomes are highly conserved multienzyme complexes responsible for proteolytic degradation of the short-lived, regulatory, misfolded, and damaged proteins. They play an important role in the processes of brain plasticity, and decrease in their function is accompanied by the development of neurodegenerative pathology. Studies performed in different laboratories both on cultured mammalian and human cells and on preparations of the rat and rabbit brain cortex revealed a large number of proteasome-associated proteins.

Mechanism of the Affinity-Enhancing Effect of Isatin on Human Ferrochelatase and Adrenodoxin Reductase Complex Formation: Implication for Protein Interactome Regulation.

Isatin (indole-2, 3-dione) is a non-peptide endogenous bioregulator exhibiting a wide spectrum of biological activity, realized in the cell via interactions with numerous isatin-binding proteins, their complexes, and (sub) interactomes. There is increasing evidence that isatin may be involved in the regulation of complex formations by modulating the affinity of the interacting protein partners. Recently, using Surface Plasmon Resonance (SPR) analysis, we have found that isatin in a concentration dependent manner increased interaction between two human mitochondrial proteins, ferrochelatase (FECH), and adrenodoxine reductase (ADR).

Proteomic profiling data of HEK293 proteins bound to human recombinant renalases-1 and -2.

Renalase (RNLS) is a recently discovered protein involved in blood pressure regulation. It exists both as an intracellular catalytically active flavoprotein (EC 1.6.

Neurotoxic Effects of Aβ6-42 Peptides Mimicking Putative Products Formed by the Angiotensin Converting Enzyme.

Angiotensin converting enzyme (ACE) is involved in proteolytic processing of the amyloid-β(Aβ) peptide implicated in the development of Alzheimer's disease (AD) and known products of ACE-based processing of Aβ42 are characterized by reduced aggregability and cytotoxicity. Recently it has been demonstrated that ACE can act as an arginine specific endopeptidase cleaving the N-terminal pentapeptide (Aβ1-5) from synthetic Aβ peptide analogues. In the context of proteolytic processing of full length Aβ42, this suggests possible formation of Aβ6-42 species.

MPTP Mouse Model of Preclinical and Clinical Parkinson's Disease as an Instrument for Translational Medicine.

Parkinson's disease (PD) is characterized by the appearance of motor symptoms many years after the onset of neurodegeneration, which explains low efficiency of therapy. Therefore, one of the priorities in neurology is to develop an early diagnosis and preventive treatment of PD, based on knowledge of molecular mechanisms of neurodegeneration and neuroplasticity in the nigrostriatal system. However, due to inability to diagnose PD at preclinical stage, research and development must be performed in animal models by comparing the nigrostriatal system in the models of asymptomatic and early symptomatic stages of PD.

Chemical modifications of amyloid-β(1-42) have a significant impact on the repertoire of brain amyloid-β(1-42) binding proteins.

The amyloid-β peptide(1-42) (Aβ) is a key player in the development and progression of Alzheimer's disease (AD). Although much attention is paid to its role in formation of extracellular amyloid plaques and protein aggregates as well as to corresponding mechanisms of their toxicity, good evidence exists that intracellular Aβ can accumulate intraneuronally and interact with intracellular target proteins. However, intracellular Aβ binding proteins as well as conditions favoring their interactions with Aβ are poorly characterized.

Use of deuterium labeling by high-temperature solid-state hydrogen-exchange reaction for mass spectrometric analysis of bradykinin biotransformation.

Rationale: Studies of molecular biodegradation by mass spectrometry often require synthetic compounds labeled with stable isotopes as internal standards. However, labeling is very expensive especially when a large number of compounds are needed for analysis of biotransformation. Here we describe an approach for qualitative and quantitative analysis using bradykinin (BK) and its in vitro degradation metabolites as an example.

Zinc-induced heterodimer formation between metal-binding domains of intact and naturally modified amyloid-beta species: implication to amyloid seeding in Alzheimer's disease?

Zinc ions and modified amyloid-beta peptides (Aβ) play a critical role in the pathological aggregation of endogenous Aβ in Alzheimer's disease (AD). Zinc-induced Aβ oligomerization is mediated by the metal-binding domain (MBD) which includes N-terminal residues 1-16 (Aβ1-16). Earlier, it has been shown that Aβ1-16 as well as some of its naturally occurring variants undergoes zinc-induced homodimerization via the interface in which zinc ion is coordinated by Glu11 and His14 of the interacting subunits.

Human urinary renalase lacks the N-terminal signal peptide crucial for accommodation of its FAD cofactor.

Renalase is a recently discovered secretory protein involved in the regulation of blood pressure. Cells synthesize all known isoforms of human renalase (1 and 2) as flavoproteins. Accommodation of FAD in the renalase protein requires the presence of its N-terminal peptide.

The effects of endogenous non-peptide molecule isatin and hydrogen peroxide on proteomic profiling of rat brain amyloid-β binding proteins: relevance to Alzheimer's disease?

The amyloid-β peptide is considered as a key player in the development and progression of Alzheimer's disease (AD). Although good evidence exists that amyloid-β accumulates inside cells, intracellular brain amyloid-binding proteins remain poorly characterized. Proteomic profiling of rat brain homogenates, performed in this study, resulted in identification of 89 individual intracellular amyloid-binding proteins, and approximately 25% of them were proteins that we had previously identified as specifically binding to isatin, an endogenous neuroprotector molecule.

In macropore tryptic digestion at acidic pH and its implication for proteomics.

Gan et al. (Proteomics 2013, 13, 3117-3123) described a new "macropore" protocol for effective protein digestion by trypsin suitable for a wide range of pH including acidic pH. It was effective not only in experiments with solutions of a model protein (myoglobin), but also with a subfraction of rat liver cytosol.

Construction of the coding sequence of the transcription variant 2 of the human Renalase gene and its expression in the prokaryotic system.

Renalase is a recently discovered protein, involved in regulation of blood pressure in humans and animals. Although several splice variants of human renalase mRNA transcripts have been recognized, only one protein product, hRenalase1, has been found so far. In this study, we have used polymerase chain reaction (PCR)-based amplification of individual exons of the renalase gene and their joining for construction of full-length hRenalase2 coding sequence followed by expression of hRenalase2 as a polyHis recombinant protein in Escherichia coli cells.

Strain differences in profiles of dopaminergic neurotransmission in the prefrontal cortex of the BALB/C vs. C57Bl/6 mice: consequences of stress and afobazole.

We found that in mice the basal activity of monoamine oxidase B (MAO-B) in the medial prefrontal cortex (mPFC) is lower in BALB/C than in C57Bl/6J mice, whereas activity of MAO-A is similar between strains. BALB/C mice, in comparison to C57Bl/6N mice, have higher basal content of dopamine in the mPFC, in both microdialysates and tissue content. Novelty stress (open field test) elicits a further increase in the microdialysate levels of dopamine in BALB/C, but not in C57Bl/6N mice; a subsequent accumulation of extracellular 3,4-dioxyphenylacetic acid (DOPAC) reaffirms the difference in catabolic capacity of monoaminergic systems between the strains.

Chromosome 18 transcriptome profiling and targeted proteome mapping in depleted plasma, liver tissue and HepG2 cells.

The final goal of the Russian part of the Chromosome-centric Human Proteome Project (C-HPP) was established as the analysis of the chromosome 18 (Chr 18) protein complement in plasma, liver tissue and HepG2 cells with the sensitivity of 10(-18) M. Using SRM, we have recently targeted 277 Chr 18 proteins in plasma, liver, and HepG2 cells. On the basis of the results of the survey, the SRM assays were drafted for 250 proteins: 41 proteins were found only in the liver tissue, 82 proteins were specifically detected in depleted plasma, and 127 proteins were mapped in both samples.

Use of biotinylated ubiquitin for analysis of rat brain mitochondrial proteome and interactome.

Applicability of in vitro biotinylated ubiquitin for evaluation of endogenous ubiquitin conjugation and analysis of ubiquitin-associated protein-protein interactions has been investigated. Incubation of rat brain mitochondria with biotinylated ubiquitin followed by affinity chromatography on avidin-agarose, intensive washing, tryptic digestion of proteins bound to the affinity sorbent and their mass spectrometry analysis resulted in reliable identification of 50 proteins belonging to mitochondrial and extramitochondrial compartments. Since all these proteins were bound to avidin-agarose only after preincubation of the mitochondrial fraction with biotinylated ubiquitin, they could therefore be referred to as specifically bound proteins.

Novel pyridazino[4,3-b]indoles with dual inhibitory activity against Mycobacterium tuberculosis and monoamine oxidase.

Tuberculosis is one of the most common infectious diseases known to man. About 37% of the world's population (about 1.86 billion people) are infected with Mycobacterium tuberculosis.

Computer visualisation of the active site of monoamine oxidase-A by means of selective inhibitors.

Computer visualisation of the active site of monoamine oxidase (MAO) is based on an assumption that the specific and reversible interaction of a ligand (substrate or inhibitor) with the substrate-binding region of the active site requires shape complementarity. The size of the ligand must allow its accommodation at the substrate-binding region. Analysis of the MAO-inhibitory activity of rigid analogues of isatin and pirlindole revealed a dependence between three-dimensional linear sizes of these molecules and the efficacy of inhibition of both MAO-A and MAO-B.

Tribulin and endogenous MAO-inhibitory regulation in vivo.

Tribulin is the name given to a family of endogenous nonpeptide substances which inhibit monoamine oxidase (MAO) and benzodiazepine binding. It is widely distributed in mammalian tissues and body fluids, and exhibit some species and tissue variations. Several components selectively inhibiting MAO A, MAO B, central and peripheral benzodiazepine binding (tribulins A, B, BZc and BZp, respectively) have been recognised.

Computer modelling and visualization of active site of monoamine oxidases.

In spite of significant progress in MAO research culminating in the crystallization of the MAO B, many structure-functional aspects of these enzymes still require better characterization. Computer modelling of the substrate/inhibitory binding region of the active site includes consensus overlay of several series of fully reversible and/or tightly bound inhibitors onto a rigid referent inhibitor(s). The shape of resultant mould obviously reflects spatial characteristic features of the substrate/inhibitor binding region.