Defatting and Clarification of Protein Hydrolysates by Using Chitosan Solutions

The possibility of the use of small amounts of chitosan for defatting and clarification of protein solutions prepared by enzymatic hydrolysis was tested. The following treatment conditions were shown to be optimal: a chitosan concentration range, from 1.0 to 1.5 gram per kilogram raw weight; pH of the precipitation medium from 8.0 to 8.5; and duration of the incubation of the protein hydrolysate solution with chitosan, less than 1 h. The hydrolysate defatting grade was found to depend on the degree of chitosan deacetylation. A possible mechanism of the chitosan-induced effects was suggested. The use of chitosan allows the mass fraction of enzyme protein hydrolysates to be reduced fourfold to fivefold.     

Association of low-density lipoprotein with particulate connective tissue matrix components enhances cholesterol accumulation in cultured subendothelial cells of human aorta

Low-density lipoproteins (LDL) were incubated with elastin particles, collagenase-resistant debris isolated from human aorta, and latex beads of 1.13 microns in diameter. As a result of incubation, insoluble LDL-associates were formed. These associates, as well as LDL-heparin-fibronectin-gelatin complexes described by other workers, were added to a 7-day primary culture of enzyme-isolated cells of human aortic subendothelial intima. The culture contained a mixed cell population made up mostly of typical and modified smooth muscle cells. 24 h later, total cholesterol, phospholipid, triacylglycerol, free cholesterol and cholesteryl ester levels were measured. Addition of insoluble LDL-complexes as well as LDL-associates to culture brought about a substantial accumulation of intracellular lipids; primarily, cholesteryl esters. The total cholesterol level in cultured cells was raised 3- to 8-fold. Addition of free LDL or LDL-free particles had no effect on the content of intracellular lipids. The results obtained allow the assumption that the occurrence of the LDL-mediated accumulation of intracellular lipids is due mainly to the LDL penetration inside the cell via 'nonspecific' phagocytosis and not through a regulated receptor-dependent pathway.     

Purification and characterization of a protein associated with peripheral-type benzodiazepine binding sites

The photoaffinity ligand [3H]PK 14105 was utilized to modify covalently peripheral-type benzodiazepine binding sites in rat adrenal mitochondrial preparations. The photolabeled membrane preparations were then solubilized in 1% digitonin and the detergent-soluble extracts subjected to fractionation by ion-exchange chromatography and reversed-phase high performance liquid chromatography. This scheme resulted in the purification of the putative binding site protein for PK 14105 which we have entitled PKBS. Purified preparations of PKBS exhibited a single band with a Mr of approximately 17,000 when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by silver-staining or autoradiographic detection. Additional criteria examining the purity of PKBS preparations were provided by radioiodination with Bolton-Hunter reagent, amino acid analysis, gas-phase sequencing, and reversed-phase chromatography suggesting that this protein was purified to apparent homogeneity. These results demonstrate that a protein associated with peripheral-type benzodiazepine recognition sites has been isolated thus facilitating more direct studies on the structure of this receptor and on the role of these binding sites in mediating responses elicited by benzodiazepines acting at these sites.     

Neuropharmacologic analysis of the dopamin-, cholin- and GABA-ergic systems of the brain in the organization of reflexes to time

Neurochemical mechanisms and structural-functional relations of conditioned reflex to time, temporal prognosing, and trace processes were studied in freely behaving intact cats and cats with lesions of the frontal cortex and the head of the caudate nucleus. It has been found that reactions to time are controlled mainly by cholinergic brain structures, temporal prognosing is controlled by dopaminergic mediation, and the trace phenomena--by GABA-ergic system. The data obtained and the methods applied may be used in analysis of some psychopathological symptoms such as desorientation in time, confabulatory confusion, mnestic disorders.     

Role of interstellar molecules in prebiological evolution

Three generations of organic molecules in space are considered: interstellar molecules, molecules synthesised in protosolar cloud and molecules synthesised on the Earth. It is shown that there is no possibilities for amino acid polymers to be synthesised under interstellar cloud conditions. Molecules of the second generation were disintegrated during the Earth accumulation period. The problem of the origin of life is connected with the evolution of molecules of the third generation.     

The effect of removal of the frontal region of the brain on conditioned reflexes to time and available stimuli]

The experiments were made on six dogs by the motor alimentary technique. It has been shown that ablation of the frontal lobe (fields: F1; F2; F3; F4) does not eliminate previously elaborated conditioned reflexes to time, temporal differentiations and reversals. They were disturbed because of motor perseverance only during the first one to three months. A conditioned reflex to time and temporal differentiations are elaborated much slower in dogs with a preliminary lobectomy, as compared with intact animals. A conclusion is drawn that the frontal lobe is not directly involved in counting the time macrointervals.