[Knockout of Hsp70 Genes Modulates Age-Related Transcriptomic Changes in Leg Muscles and Reduces the Locomotion Speed and Lifespan of Drosophila melanogaster].

This study investigated the effect of knockout of six Hsp70 genes (orthologues of the mammalian genes Hspa1a, Hspa1b, Hspa2, and Hspa8) on age-related changes in gene expression in the legs of Drosophila melanogaster, which contain predominantly skeletal muscle bundles. For this, the leg transcriptomic profile was examined in males of the w^(1118) control strain and the Hsp70^(-) strain on the 7th, 23rd and 47th days of life. In w^(1118) flies, an age-related decrease in the locomotion (climbing) speed (a marker of functional state and endurance) was accompanied by a pronounced change in the transcriptomic profile of the leg skeletal muscles, which is conservative in nature. In Hsp70^(-) flies, the median lifespan was shorter and the locomotion speed was significantly lower compared to the control; at the same time, complex changes in the age-related dynamics of the skeletal muscle transcriptome were observed. Mass spectrometry-based quantitative proteomics showed that 47-day-old Hsp70^(-) flies, compared with w^(1118) flies, demonstrated multidirectional changes in the contents of key enzymes of glucose metabolism and fat oxidation (glycolysis, pentose phosphate pathway, Krebs cycle, beta-oxidation, and oxidative phosphorylation). Such dysregulation may be associated with a compensatory increase in the expression of other genes encoding chaperones (small Hsp, Hsp40, 60, and 70), which regulate specific sets of target proteins. Taken together, our data show that knockout of six Hsp70 genes slightly reduced the median lifespan of flies, but significantly reduced the locomotion speed, which may be associated with complex changes in the transcriptome of the leg skeletal muscles and with multidirectional changes in the contents of key enzymes of energy metabolism.

The neuroprotective effect of isatin in the rotenone-induced model of parkinonism in rats: the study of delayed effects.

Parkinsonism in rats induced by the pesticide rotenone is one of the most adequate models of Parkinson's disease (PD). Isatin (indole-2,3-dione) is an endogenous regulator found in mammals and humans and exhibiting a wide range of biological activities mediated by numerous isatin-binding proteins, including those associated with neurodegenerative pathology. A course of rotenone administration to rats caused behavioral impairments and changes in the profile and relative content of isatin-binding proteins in the brain. In this study, we have investigated the delayed neuroprotective effect of isatin (5 days after completion of the course of rotenone administration) on behavioral reactions and the relative content of isatin-binding proteins in the brain of rats with rotenone-induced experimental parkinsonism. Although during this period the rats retained locomotor dysfunction, the proteomic analysis data (profile of isatin-binding proteins in the brain and changes in their relative content) differed from the results obtained immediately after completion of the course of rotenone administration. Moreover, all isatin-binding proteins with altered relative content changed during this period are associated to varying degrees with neurodegeneration (many with Parkinson's and Alzheimer's diseases).

Detection of low-copy proteins in proteomic studies: issues and solutions.

Detection of low-copy proteins in complex biological samples is one of the most important issues of modern proteomics. The main reason for inefficient detection of low protein concentrations is the insufficient sensitivity of mass spectrometric detectors and the high dynamic range of protein concentrations. In this study we have investigated the possibilities and limitations of a targeted mass spectrometric analysis using the reconstructed system of standard proteins UPS1 (Universal Proteomic Standard 1) as an example. The study has shown that the sensitivity of the method is affected by the concentration of target proteins of the UPS1 system, as well as by a high level of biological noise modelled by proteins of whole E. coli cell lysate. The limitations of the method have been overcome by concentrating and pre-fractionating the sample peptides in a reversed phase chromatographic system under alkaline elution conditions. Proteomic analysis of the biological sample (proteins of the human hepatocellular carcinoma cell line HepG2 encoded by genes of human chromosome 18) showed an increase in the sensitivity of the method as compared to the standard targeted mass spectrometric analysis. This culminated in registration of 94 proteins encoded by genes located on human chromosome18.

Proteome of plasma extracellular vesicles as a source of colorectal cancer biomarkers.

The search for minimally invasive methods for diagnostics of colorectal cancer (CRC) is the most important task for early diagnostics of the disease and subsequent successful treatment. Human plasma represents the main type of biological material used in the clinical practice; however, the complex dynamic range of substances circulating in it complicates determination of CRC protein markers by the mass spectrometric (MS) method. Studying the proteome of extracellular vesicles (EVs) isolated from human plasma represents an attractive approach for the discovery of tissue-secreted CRC markers. We performed shotgun mass spectrometry analysis of EV samples obtained from plasma of CRC patients and healthy volunteers. This MS analysis resulted in identification of 370 proteins (which were registered by at least two peptides). Stable isotope-free relative quantitation identified 55 proteins with altered abundance in EV samples obtained from plasma samples of CRC patients as compared to healthy controls. Among the EV proteins isolated from blood plasma we found components involved in cell adhesion and the VEGFA-VEGFR2 signaling pathway (TLN1, HSPA8, VCL, MYH9, and others), as well as proteins expressed predominantly by gastrointestinal tissues (polymeric immunoglobulin receptor, PIGR). The data obtained using the shotgun proteomic profiling may be added to the panel for targeted MS analysis of EV-associated protein markers, previously developed using CRC cell models.

Proteomic profiling of renal tissue of normo- and hypertensive rats with the renalase peptide RP220 as an affinity ligand.

Renalase (RNLS) is a recently discovered protein that plays an important role in the regulation of blood pressure by acting inside and outside cells. Intracellular RNLS is a FAD-dependent oxidoreductase that oxidizes isomeric forms of ß-NAD(P)H. Extracellular renalase lacking its N-terminal peptide and cofactor FAD exerts various protective effects via non-catalytic mechanisms. Certain experimental evidence exists in the literature that the RP220 peptide (a 20-mer peptide corresponding to the amino acid sequence RNLS 220-239) reproduces a number of non-catalytic effects of this protein, acting on receptor proteins of the plasma membrane. The possibility of interaction of this peptide with intracellular proteins has not been studied. Taking into consideration the known role of RNLS as a possible antihypertensive factor, the aim of this study was to perform proteomic profiling of the kidneys of normotensive and hypertensive rats using RP220 as an affinity ligand. Proteomic (semi-quantitative) identification revealed changes in the relative content of about 200 individual proteins in the kidneys of hypertensive rats bound to the affinity sorbent as compared to the kidneys of normotensive animals. Increased binding of SHR renal proteins to RP220 over the normotensive control was found for proteins involved in the development of cardiovascular pathology. Decreased binding of the kidney proteins from hypertensive animals to RP220 was noted for components of the ubiquitin-proteasome system, ribosomes, and cytoskeleton.

Comparative proteomic analysis of renal tissue of normotensive and hypertensive rats.

Comparative proteomic analysis of kidney tissue from normotensive (WKY) and spontaneously hypertensive (SHR) rats revealed quantitative and qualitative changes in renal proteins. The number of renal proteins specific for WKY rats (blood pressure 110-120 mm Hg) was 13-16. There were 20-24 renal proteins specific for SHR (blood pressure 180 mm Hg and more). The total number of identified renal proteins common for both rat strains included 972-975 proteins. A pairwise comparison of all possible (SHR-WKY) variants identified 8 proteins specific only for normotensive (WKY) animals, and 7 proteins specific only for hypertensive ones (SHR). Taking into consideration their biological roles, the lack of some enzyme proteins in hypertensive rats (for example, biliverdin reductase A) reduces the production of molecules exhibiting antihypertensive properties, while the appearance of others (e.g. betaine-homocysteine S-methyltransferase 2, septin 2, etc.) can be interpreted as a compensatory reaction. Renal proteins with altered relative content (with more than 2.5-fold change) accounted for no more than 5% of all identified proteins. Among the proteins with an increased relative content in hypertensive animals, the largest group consisted of proteins involved in the processes of energy generation and carbohydrate metabolism, as well as antioxidant and protective proteins. In the context of the development of hypertension, the identified relative changes can apparently be considered compensatory. Among the proteins with the most pronounced decrease in the relative content in hypertensive rats, the dramatic reduction in acyl-CoA medium-chain synthetase-3 (ACSM3) appears to make an important contribution to the development of renal pathology in these animals.

The delayed effect of rotenone on the relative content of brain isatin-binding proteins of rats with experimental parkinsonism.

Isatin (indoldione-2,3) is an endogenous biological regulator found in the brain, peripheral tissues, and biological fluids of humans and animals. Its biological activity is realized via isatin-binding proteins, many of which were identified during proteomic profiling of the brain of mice and rats. A number of these proteins are related to the development of neurodegenerative diseases. Previously, using a model of experimental Parkinsonism induced by a seven-day course of rotenone injections, we have observed behavioral disturbances, as well as changes in the profile and relative content of brain isatin-binding proteins. In this study, we have investigated behavioral responses and the relative content of brain isatin-binding proteins in rats with rotenone-induced Parkinsonism 5 days after the last administration of this neurotoxin. Despite the elimination of rotenone, animals exhibited motor and coordination impairments. Proteomic profiling of isatin-binding proteins revealed changes in the relative content of 120 proteins (the relative content of 83 proteins increased and that of 37 proteins decreased). Comparison of isatin-binding proteins characterized by the changes in the relative content observed in the brain right after the last injection of rotenone (n=16) and 5 days later (n=11) revealed only two common proteins (glyceraldehyde-3-phosphate dehydrogenase and subunit B of V-type proton ATPase). However, most of these proteins are associated with neurodegeneration, including Parkinson's and Alzheimer's diseases.

System analysis of surface CD markers during the process of granulocytic differentiation.

Plasma membrane proteins with extracellular-exposed domains are responsible for transduction of extracellular signals into intracellular responses, and their accessibility to therapeutic molecules makes them attractive targets for drug development. In this work, using omics technologies and immunochemical methods, we have studied changes in the content of markers of clusters of differentiation (CD markers) of neutrophils (CD33, CD97, CD54, CD38, CD18, CD11b, CD44, and CD71) at the level of transcripts and proteins in NB4, HL-60 and K562 cell lines, induced by the treatment with all-trans-retinoic acid (ATRA). Transcriptomic analysis revealed the induction of CD38, CD54, CD11b, and CD18 markers as early as 3 h after the addition of the inducer in the ATRA-responsive cell lines HL-60 and NB4. After 24 h, a line-specific expression pattern of CD markers could be observed in all cell lines. Studies of changes in the content of CD antigens by means of flow cytometry and targeted mass spectrometry (MS) gave similar results. The proteomic profile of the surface markers (CD38, CD54, CD11b, and CD18), characteristic of the NB4 and HL-60 lines, reflects different molecular pathways for the implementation of ATRA-induced differentiation of leukemic cells into mature neutrophils.

Neuroprotective effects of isatin and afobazole in rats with rotenone-induced Parkinsonism are accompanied by increased brain levels of Triton X-100 soluble alpha-synuclein.

Effects of the endogenous neuroprotector isatin and the pharmacological drug afobazole (exhibiting neuroprotective properties) on behavioral reactions and quantitative changes in the brain proteomic profile have been investigated in rats with experimental rotenone Parkinsonism. A single dose of isatin (100 mg/kg subcutaneously on the last day of a 7-day course of rotenone administration) improved the motor activity of rats with rotenone-induced Parkinsonism in the open field test (horizontal movements) and the rotating rod test. Afobazole (10 mg/kg intraperitoneally, daily during the 7-day course of rotenone administration) reduced the manifestations of rigidity and postural instability. Proteomic analysis, performed using brain samples obtained the day after the last administration of rotenone and neuroprotectors, revealed similar quantitative changes in the brain of rats with rotenone Parkinsonism. An increase in the relative content of 65 proteins and a decrease in the relative content of 21 proteins were detected. The most pronounced changes - an almost ninety-fold increase in the alpha-synuclein content - were found in the brains of rats treated with isatin. In animals of the experimental groups treated with "Rotenone + Isatin", as well as "Rotenone + Afobazole", the increase in the relative content of this protein in the brain was almost 60 and 50 times higher than the control values. Taking into consideration the known data on the physiological role of alpha-synuclein, an increase in the content of this protein in the brain upon administration of neuroprotectors to animals with rotenone Parkinsonism may represent a compensatory reaction, at least in the early stages of this disease and the beginning of its treatment.

Quantitative changes of brain isatin-binding proteins of rats with the rotenone-induced experimental parkinsonism.

Isatin (indoldione-2,3) is an endogenous regulator found in humans and animals. It exhibits a broad range of biological activity mediated by numerous isatin-binding proteins. Isatin produces neuroprotective effects in several experimental models of diseases, including Parkinsonism induced by the neurotoxin MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine).Rotenone (a neurotoxin used to modeling Parkinson's disease in rodents) causes significant changes in the profile of isatin-binding proteins of rat brain. Comparative proteomic identification of brain proteins of control rats and the rats with the rotenone-induced Parkinsonian syndrome (PS) revealed significant quantitative changes of 86 proteins under the influence of rotenone. This neurotoxin mainly caused the increase of the quantity of proteins involved in signal transduction and regulation of enzyme activity (24), proteins involved in cytoskeleton formation and exocytosis (23), and enzymes involved in energy generation and carbohydrate metabolism (19). However, only 11 of these proteins referred to isatin-binding proteins; the content of eight of them increased while the content of three proteins decreased. This suggests that the dramatic change of the profile of isatin-binding proteins, found in the development of the rotenone-induced PS, comes from changes in the state of the pre-existing molecules of proteins, rather than altered expression of corresponding genes.

[Antibody proteomics]. / Proteomika antitel.

Antibodies represent an essential component of humoral immunity; therefore their study is important for molecular biology and medicine. The unique property of antibodies to specifically recognize and bind a certain molecular target (an antigen) determines their widespread application in treatment and diagnostics of diseases, as well as in laboratory and biotechnological practices. High specificity and affinity of antibodies is determined by the presence of primary structure variable regions, which are not encoded in the human genome and are unique for each antibody-producing B cell clone. Hence, there is little or no information about amino acid sequences of the variable regions in the databases. This differs identification of antibody primary structure from most of the proteomic studies because it requires either B cell genome sequencing or de novo amino acid sequencing of the antibody. The present review demonstrates some examples of proteomic and proteogenomic approaches and the methodological arsenal that proteomics can offer for studying antibodies, in particular, for identification of primary structure, evaluation of posttranslational modifications and application of bioinformatics tools for their decoding.

[Characteristics of behavioral reactions and the profile of brain isatin-binding proteins of rats with the rotenone-induced experimental parkinsonism]. / Osobennosti povedencheskikh reaktsii i profilia izatin-sviazyvaiushchikh belkov mozga u krys s indutsirovannym rotenonom éksperimental'nym parkinsonizmom.

The neurotoxins rotenone and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (МPTP) are used for modeling Parkinson's disease in animals (PD). They induce the mitochondrial respiratory chain dysfunction, which leads to the dopaminergic (DA) neuron degeneration. The advantage of the rotenone model consists in ability of rotenone to cause neurodegeneration showing symptoms and molecular biological characteristics similar to those of PD. Isatin (indoldione-2,3) is an endogenous regulator found in tissues and biological fluids of humans and animals. It exhibits a broad range of biological activity mediated by numerous isatin-binding proteins. In this work we have investigated behavioral reactions and profiles of brain isatin-binding proteins of rats with Parkinson's syndrome (PS) in comparison with the corresponding parameters of MPTP-induced Parkinsonism in mice. Systemic injection of rotenone caused severe PS comparable with the effect of MPTP injection. It was accompanied by significant body weight loss, death, oligokinesia, muscular rigidity, and postural instability of animals. In spite of the same pathogenic basis of PS caused by rotenone and MPTP, the molecular mechanisms of their action differ. In the case of rotenone-induced PS, the pool of isatin-binding proteins common of the control rats and the rats with PS (146) significantly exceeded the pool of the common proteins of control mice and mice with PS induced by MPTP, whether right after neurotoxin injection (27), or (all the more) in a week after the MPTP injection (14). The comparison of isatin-binding proteins specific of the animals with MPTP-induced PS and with the rotenone-induced PS (as compared with the control animals) revealed total absence of proteins common of these two models of PD. It is to be noted that both neurotoxins particularly affected the proteins participating in the signal transmission and enzyme activity regulation. The changes of the profile of isatin-binding proteins in response to the injection of rotenone suggest that the neuroprotector isatin could also influence positively in the case of the rotenone model of PD.

[Comparative analysis of proteins associated with 26S and 20S proteasomes isolated from rabbit brain and liver]. / Sravnitel'nyi analiz belkov, assotsiirovannykh s 26S i 20S proteasomami mozga i pecheni krolika.

We have isolated fractions of 26S and 20S proteasomes were from the rabbit liver and the brain. According to mass spectrometric (MS) analysis, the 26S proteasome fractions from these organs contained catalytic and regulatory subunits characteristic of the proteasome core and regulatory subunits. The 20S fractions of brain and liver proteasomes contained only catalytic proteasome subunits. In addition to proteasome subunits, the isolated fractions contained components of the ubiquitin-proteasome system, ubiquitinated proteins, enzymes that play an important role in metabolic processes, cytoskeletal components, signaling, regulatory, and protective proteins, as well as proteins regulating gene expression, cell division, and differentiation. The abundance of a number of proteasome-associated proteins was comparable or exceeded the abundance of intrinsic proteasome components. About a third of the proteins common to all studied fractions (26S and 20S of brain and liver proteasomes) belong to the group of multifunctional proteins. Selective biosensor validation confirmed the affinity binding of proteins (aldolase, phosphoglycerate kinase) identified during MS analysis to the brain 20S proteasome. Comparison of the subproteomes of the 26S and 20S brain proteasomes showed that removal of components of the regulatory (19S) subparticles caused almost two-fold increase in the total number of individual proteins associated with the core part of the proteasome (20S). In the liver, the number of proteins associated with the core part of the proteasome remained basically unchanged after the removal of the components of the regulatory (19S) subparticles. This indicates that in the brain and, possibly, in other organs, proteins of the regulatory (19S) subunit play an important role in the formation of the proteasome interactome.

Protein dataset of immortalized keratinocyte HaCaT cells and normal human keratinocytes.

Learning of the molecular mechanisms of the pathological processes development in the normal human keratinocytes (NHK) are difficult. Immortalized keratinocytes HaCaT are often used as an analogue of NHK since they have a number of advantages over the latter - they do not require the presence of growth and differentiation factors in the medium, have unlimited potential for proliferation, demonstrate stable phenotype regardless of the number of passages [1]. Taking into account the properties and characteristics of the HaCaT line, these cells can be considered as a promising experimental model for research of various physiological processes occurring in human keratinocytes. However, to understand the limitations of such an experimental model, a detailed comparative characterization of HaCaT and NHK is required, which can be obtained by carrying out its proteomic analysis. In this article we present datasets obtained through the high-throughput shotgun proteomics analysis of normal human keratinocytes and immortalized HaCaT keratinocytes. As a protocol for proteomic profiling of cells, we used the approach of obtaining LC-MS / MS measurements followed by their processing with Progenesis LC-MS software (Nonlinear Dynamics Ltd.). The mzML files were deposited to the Mendeley Data.

[Comparative study of the human keratinocytes proteome of the HaCaT line: identification of proteins encoded by genes of 18 chromosomes under the influence of detergents]. / Sravnitel'noe issledovanie proteoma kletok HaCaT keratinotsitov cheloveka: identifikatsiia belkov, kodiruemykh genami 18 khromosomy pri vozdeistvii detergentov.

Using electrospray ionization tandem mass spectrometry, a comparative analysis of the HaCaT keratinocyte proteins encoded by the 18th chromosome was performed before and after exposure to sodium dodecyl sulfate (25 mg/ml) and to Triton X-100 (12.5 mg/ml) in a subtoxic dose for 48 hours. Proteins were identified using the SearchGUI platform (X!Tandem and MS-GF+ search engines). In total, 1284 proteins were found in immortalized human HaCaT keratinocytes and about 75% of them were identified by two or more peptides. Were identified, that 26 proteins were encoded by genes of chromosome 18. Among these proteins, 17 were common for control cells and HaCaT cells treated with SDS. Proteins MARE2 and CTIF were identified only in control keratinocytes. Seven identified proteins encoded by genes of chromosome 18 were found only in detergent-treated keratinocytes: LMAN1, NDUV2, SPB3, VPS4B, KDSR, ROCK1 and RHG28.

Intracellular Transport of Ribosome-Inactivating Proteins Depends on Annexin 13.

In the present study, we assessed the role of annexin 13 membrane-binding protein (ANXA13) in the intracellular transport of vesicles containing type II ribosome-inactivating proteins (RIP-IIs). A modified human intestinal epithelial cell line HT29 was used, in which the expression of ANXA13 was significantly reduced. The cytotoxic effect of ricin and viscumin was evaluated by modification of 28S ribosome RNA. The observed differences in the activity of toxins on the parental and modified HT29 lines indicate that ANXA13 plays a different role in the intracellular transport of vesicles containing the RIP-IIs.

[Mass-spectrometric MRM analysis of FDA-verified proteins in the blood plasma of healthy volunteers]. / Mass-spektrometricheskii MRM analiz FDA-verifitsirovannykh belkov v plazme krovi zdorovykh dobrovol'tsev.

The proteomic composition of a biological sample serves as the most important feature of a biological object, and it allows discriminating normal and pathological conditions. Targeted mass spectrometric analysis, namely, multiple reaction monitoring (MRM) using synthetic isotopically-labeled internal standard (SIS), is the main alternative to the ELISA method for the analysis of diagnostically significant proteins. Based on the MRM results, a prototype test system has been developed; it employs the targeted mass spectrometric method for multiplex, quantitative analysis of FDA-verified proteins in whole blood plasma. Using this approach, it was possible to measure the content of 42 proteins in 31 samples in a concentration range spanning five orders of magnitude. The interindividual variability for 30 of the 42 registered proteins was less than 40%. The largest scatter was observed for haptoglobin (68%), immunoglobulin heavy constant delta IGHD (90%), angiotensin (72%), sex hormone-binding globulin SHBG (100%) and lipoprotein-(a) (136%). The obtained results on the concentration of proteins correlate with published data (Hortin et al., 2008, Clinical Chemistry, 54, 1608) with R2=0.84. The developed prototype test system based on targeted mass spectrometric analysis of proteins can be considered as an alternative to methods using monoclonal antibodies.

Proteome dataset of mouse macrophage cell line infected with tick-borne encephalitis virus.

We report the proteomic datasets on the mouse macrophage cell line PMJ2R infected with tick-borne encephalitis virus (TBEV) for two and six days. Data were acquired using shotgun ultra-high resolution mass spectrometry. Peptide identifications were done using the Mascot version 2.4 (Matrix Science), and quantification was performed by a label-free approach. Protein profiles of early (two days) and late (six days) stages of infection were compared between each other and the respective control samples. Protein profiles of infected and control samples differed in the number of identified proteins and their relative abundances. Proteins detected in the TBEV-infected cells were involved in various processes related to the infection, including defense response against the virus, regulation of viral process, negative regulation of viral genome replication, RNA binding, or innate immune response. Also, proteins specific for the early and late stages of infection were identified.

[Exosomes of malignant tumors: prospects of omiсs diagnostics]. / Ékzosomy zlokachestvennykh opukholei: perspektivy omiksnoi diagnostiki.

The main problems in the diagnostics and treatment of malignant tumors are early detection of the disease, prediction of the course of the disease and response to therapy. The solution may be associated with identification of biomarkers secreted by tumor cells within extracellular vesicles, known as exosomes. The study of exosome proteins attracts special attention, because their molecular composition can have information about tumor identity, and also represent a set of signaling molecules that regulate the processes of tumor progression and growth. In addition, the analysis of exosomes secreted into the extracellular space corresponds to the promising concept of a liquid biopsy. In this review, we have summarized the current experience in the molecular study of exosomes in various types of malignant tumors, including colorectal cancer, lung cancer, ovaries, prostate and breast cancer, with special emphasis on omics methods and outlined the prospects for their use in diagnosis.

[The effect of a neuroprotective dose of isatin or deprenyl to mice on the profile of brain isatin-binding proteins]. / Izmenenie profilia izatin-sviazyvaiushchikh belkov mozga myshei pri odnokratnom vvedenii neiroprotektornoi dozy izatina ili deprenila.

Isatin (indol-2,3-dione), an endogenous biofactor found in the brain, peripheral tissues and biological body fluids of humans and animals, exhibits a wide range of biological and pharmacological activities. They are realized via interaction with numerous isatin-binding proteins. Some of these proteins identified during proteomic profiling of the brain are involved in the development of neurodegenerative pathology. In the context of the neuroprotective effect, the effect of isatin is comparable to the effects of deprenyl (selegiline), a pharmacological agent used for treatment of Parkinson's disease. In this study, we have investigated the effect of a single dose administration of isatin (100 mg/kg) and deprenyl (10 mg/kg) to mice on the profile of the brain isatin-binding proteins. Comparative proteomic analysis of brain isatin-binding proteins of mice treated with isatin or deprenyl resulted in identification of a representative group of proteins (n=200) sensitive to the administration of these substances. The change in the profile of isatin-binding proteins may be obviously attributed to accumulation of isatin and deprenyl in the brain and their interaction with target proteins; this prevents protein binding to the affinity sorbent. Thus identified brain isatin-binding proteins of the control animals obviously represent specific targets that interact directly with isatin (and also with deprenyl) in vivo. Isatin or deprenyl administered to animals interact with these proteins and thus inhibit their binding to the affinity sorbent (immobilized isatin analogue).