Immunoenzyme determination of neurospecific antigen 10-40-4 in human and animal tissue and organ extracts

IEA of brain specific antigen 10-40-4 in human and animal organs and tissues was elaborated. The method permits measuring the concentration of the antigen within the range from 1 to 120 ng/ml. The use of the method made it possible to confirm brain specificity of protein 10-40-4, since its brain content is 1500 to 2000 times higher than in other organs, and to estimate the percentage of cross-reaction between antigenic determinants of brain specific antigen 10-40-4 from different species of animals.     

Neurospecific and neuron-specific enolase levels in human nerve tissue at early stages of embryogenesis

Neurospecific and neuro-nonspecific isozymes of glycolytic enzyme enolase known to be molecular markers of neuronal and glial cells respectively were isolated from human brain. Using immunoenzyme assay, the content of these proteins was measured in the brain of 7-13-week human embryos and adult subjects. The content of both isoenzymes gradually increases attaining constant level in 10-13-week embryos. Relative content of neuro-nonspecific enolase in the brain of 10-13-week embryos is 1 1/2 times higher than that in adults, whereas the content of neurospecific enolase amounts only to 2% of its level in the adult brain.     

Cytoplasmic casein kinase 2 and its substrate proteins in the brain in Alzheimer's disease]

The absence of casein kinase 2 on blots of temporal cortex extracts from Alzheimer's disease patients (ADP) was shown using antiserum to casein kinase 2. Casein kinase 2 activity towards endogenous substrates and casein is 2-5 times less in ADP brain in comparison to normal controls. The fractions of heparin-binding proteins, containing protein substrates for phosphorylation, were isolated from temporal cortex of ADP and normal controls. The total amount of heparin-binding proteins from ADP brains is less than from control brains, and the polypeptide composition of these fractions is much more poop.     

Systemic Neurochemical Alterations in Schizophrenic Brain: Glutamate Metabolism in Focus

We have used a systemic approach to establish a relationship between enzyme measures of glial glutamate and energy metabolism (glutamine synthetase and glutamine synthetase-like protein, glutamate dehydrogenase isoenzymes, brain isoform creatine phosphokinase) and two major glial proteins (glial fibrillary acidic protein and myelin basic protein) in autopsied brain samples taken from patients with schizophrenia (SCH) and mentally healthy subjects (23 and 22 cases, respectively). These biochemical parameters were measured in tissue extracts in three brain areas (prefrontal cortex, caudate nucleus, and cerebellum). Significant differences in the level of at least one of the glutamate metabolizing enzymes were observed between two studied groups in all studied brain areas. Different patterns of correlative links between the biochemical parameters were found in healthy and schizophrenic brains. These findings give a new perspective to our understanding of the impaired regulation of enzyme levels in the brain in SCH.     

Effect of immunization with neurospecific proteins and tubulin on learning in the rat

The paper deals with the effect of anticerebral antibodies on rats learning in T-shaped maze with food reinforcement. The rats of August line were immunized by neurospecific proteins 10-40-4 from the human and rat's brain, 14-3-2 and cerebral tubuline. Rats immunized by bovine serum albumine (BSA) served as a control of the influence of antibodies to noncerebral protein. Rats injected with Freund adjuvant and saline, served as control of Freund adjuvant action. At the time of antibodies formation (from the 7-th day after the last injection) the rats were trained in a T-shaped maze during 4 days. The acquisition of conditioned reactions was inhibited in rats immunized with neurospecific proteins 10-40-4 from the rats brain, 14-3-2 and cerebral tubuline. Antibodies to neurospecific protein 10-40-4 from the rats brain produced the greatest effect on the process of learning. They elicited a significant decrease of conditioning and an increase of the number of errors. Antibodies to the neurospecific protein 10-40-4 from the human brain and to the BSA, i.e. to proteins which are not present in the nervous tissue of the rats, did not affect the learning. The obtained results indirectly confirm the permeability for the antibodies of the blood-brain barrier in immunized animals.     

Damage to the creatine phosphokinase of rat brain synaptosomes during molecular oxygen activation

It was shown that activation of molecular oxygen by Fe2+ ascorbate causes damage to creatine phosphokinase of rat brain synaptosomes. The creatine phosphokinase inactivation did not correlate with activation of lipid peroxidation in synaptosomes. The enzyme damage was the result of direct interaction with active oxygen species.     

Content of neuron-specific and non-neuron-specific enolase isoenzymes in human brain structures

The distribution of neuron-specific (NSE) and non-neuronal (NNE) isoforms of glycolytic enzyme enolase (EC 4.2.I.II.) in the human brain was studied using immunoenzyme assay. The maximum NSE concentration was measured in the frontal and occipital brain cortex, hippocampus, limbic cortex and hypothalamus (12-14 micrograms/mg of water-soluble protein), the minimum level was observed in the brain stem structures (3-6 micrograms/mg). The maximum NNE content was determined in thalamus (34 micrograms/mg). The data can prove useful for the study of enolase isoform distribution in the brain of neurological and psychiatric patients.     

The decreased level of casein kinase 2 in brain cortex of schizophrenic and Alzheimer's disease patients

The content of casein kinase 2 is considerably decreased in ribosome-free extracts of the frontal cortex of schizophrenic and Alzheimer's disease patients in comparison to normal brains as has been demonstrated by means of immunoblotting. The activity of casein kinase 2 towards endogenous substrates and casein is also diminished in the cases of mental pathologies examined. This phenomenon may explain the well-known aberrations in the phosphorylation of structural proteins of human brain which are intrinsic for the mental diseases.     

Cellular and regional localization of the neurospecific antigen 10-40-4 in the human brain

Cellular and regional localization of neurospecific protein 10-40-4 in human brain was studied by immunofluorescent staining and immunoenzymatic assay. Intense fluorescence of perikaryons of the medulla oblongata, thalamus and pons neurons was demonstrated. The same structures showed the maximal concentration of the protein (15-18% of water-soluble proteins). In the cortex of the hemispheres, in the cerebellum and hypothalamus the fluorescence intensity was not different from the background level. The concentration of the protein in these structures was minimal (1-4% of water-soluble proteins).