Growth of lymphoid cell cultures of the Raji line in a medium containing low-molecular serum components

The effect of fetal bovine serum ultrafiltrate, containing low-molecular components (lower than 14 000 D), on the growth of cultures of the lymphoid Raji cells and fibroblasts BHK-21 was studied. The growth of the former did not differ from that in the control (in the medium with the whole fetal serum), while the latter did not proliferate in the medium with the ultrafiltrate. Thus, the growth of the lymphoid Raji cells and fibroblasts BHK-21 is controlled by different serum components. The Raji cells were exposed to an ultrafiltrate (up to 14 000 D) of the adult animal serum whose growth stimulating activity is known to be lower than that of the fetal serum. After the removal of components with molecular weights higher than 14 000 D from the adult animal serum, the growth stimulating activity of such a serum was seen increased, but not up to the level of the fetal serum. BHK-21 cells did not proliferate in the medium with this ultrafiltrate. It is proposed that the increase in the growth stimulating activity of the whole bovine serum in respect to the Raji cells after the removal of the components with high molecular weights may be due to the removal of lymphocyte growth inhibitors whose activity depends on the age of the animal serving a donor of serum.     

The effect of blood serum components on the growth, biochemical and biological properties of streptococcus

The components of cattle blood serum, added to the medium for the cultivation of group A streptococci, considerably decrease the period of adaptation and increase the balanced growth rate of streptococci, which is manifested by changes in the surface structures of the cell wall: the absence or modification of protein M. Streptococci grown under these conditions lose their capacity for phagocytosis, and from the cell walls obtained from these streptococci no surface protein M can be isolated by pepsin treatment. Nevertheless, the ratio of the main cell-wall components (proteins, polysaccharide and peptidoglycan), the amino acid composition, as well as the resistance of the cell walls to the action of trypsin and endo-N-acetylmuramidase are the same in M+ and Mx variants, that makes it possible to infer that the modification of protein M or the inhibition of its synthesis occurs during the growth of streptococci in the presence of blood serum components.     

Variability in low-molecular subproteome of blood serum of healthy man in normal life conditions

For analysis of inter-individual variability in low-molecular serum subproteome proteome profiles of healthy men at the age of 20-30 years (36 subjects), 30-40 years (11 subjects) and 40-50 years (11 subjects) were obtained. Serum samples were fractionated on magnetic beads MB WCX using ClinProt robot prior to mass-spectrometry based profiling. Mass-spectra were obtained with time-of-flight mass-spectrometer Autoflex III ("Bruker Daltonics") in automatic mode. It was shown that low-molecular serum subproteome of healthy humans was characterized by significant inter-individual variability. 21% of all peaks in proteome profiles had coefficient of variation more than 50% and 29% of all peaks had low dispersion (CV < 30%).Therefore majority of peaks in proteome profile were peaks with moderate inter-individual variability (CV from 30% to 50%). Fragments of high-molecular kininogen, inter-alpha-trypsin inhibitor, complement components C3 and C4a, apolipoprotein CI, platelet factor IV, beta2-microglobulin and cystatin C showed wide variation among examined groups of healthy men. Dispersion of high-molecular kininogen, inter-alpha-trypsin inhibitor, apolipoproteins AII and CIII peaks increased with age.     

The biological properties of low-molecular staphylococcal peptides

Staphylopeptides with molecular weight less than 4000 Da, possessing their own specific allergic activity in skin allergic tests. immunoleukolysis test and phagocytosis breaking test were obtained by the acid extraction method.     

A low-molecular polypeptide of the blood serum in warm-blooded animals: its effect on cell adhesion and proliferation

The review deals with investigation of a 6-kDa polypeptide discovered in blood whey of warm-blooded animals. This polypeptide stimulates cell adhesion, the action being characterized by absence of tissue and species specificity. Dose dependence of biological effect, intensively is revealed: optimal are concentrations of 10(-15)--10(-19)m, at which the polypeptide stimulates in-culture fibroblast proliferation. Information is provided about biochemical investigation of the polypeptide: method of its extraction from the whey and of purification; physicochemical properties of the polypeptide extracted from blood whey of various animals and man. For one of the cattle, amino acid composition is determined. Polypeptide states in blood whey at different ontogenetic stages are studied. At earlier stages, the polypeptide is "active"; at later stages of prenatal and in postnatal development, it is "nonactive" due to its being bound by another whey substance, a "carrier". By sum of results of investigation of its physicochemical properties and biological activity, the polypeptide represents previously unstudied blood whey factor.     

Immunoenzymatic method for determining thyroglobulin levels in human blood serum]

An inexpensive enzyme immunoassay method was designed for the determination of thyroglobulin concentration in human blood serum. The range of concentrations of thyroglobulin which can be measured by the method is between 6 and 800 ng/ml. The sensitivity of the method is comparable to that of the commercial test kits. The values of thyroglobulin concentration obtained with the use of the described method are strongly correlated (r = 0.946) with those obtained by using the reference method (IRMA kit of Byk, Sweden). The intraassay coefficient of variation ranged from 5.5 to 10.2% and interassay coefficient of variation from 9.5 to 13.2% depending on the thyroglobulin concentration. The upper limit of blood serum thyroglobulin concentration in healthy subjects was 70 ng/ml. The results of thyroglobulin determination obtained with the described method are falsely lowered in the presence of antithyroglobulin antibodies; simultaneous determination of these antibodies is thus necessary in such a case. It seems that the described method may be used for monitoring the patients after surgical treatment of differentiated thyroid cancer aimed at early detection of metastases.     

The binding of plutonium to serum proteins in vitro

The interactions between tetravalent plutonium and horse serum proteins were studied in vitro by electrophoresis on cellulose acetate and by gel filtration. The results show that in horse serum, as in other mammalian sera, the plutonium is associated principally with the transferrin component of the beta1-globulins. The formation of the plutonium-transferrin complex requires the presence of HCO3-, and plutonium is displaced from the complex by excess iron, thus indicating that similar binding sites may be involved in the complexing of iron and plutonium. The plutonium complex is considered to be less stable than the iron-transferrin complex, but plutonium can only be released from the transferrin complex by citrate or stronger chelating agents.     

Use of a chromatographic method for determining kallikrein and prekallikrein in dog blood serum

The authors determined the conditions of chromatography to be used for determination of prekallikrein and kallikrein in the dog blood serum. The enzyme and its precursor do not adsorb on DEAE-Sephadex A-50 in a 0.02 M phosphate buffer, pH 7, containing 0.15 M NaCl, and thus their quantity can be determined in a non-adsorbed protein fraction from the rate of hydrolysis of N-benzoyl-L-arginine ethyl ester before and after exposure to trypsin. In 1 ml of the dog blood serum, kallikrein activity ranged from 0 to 60 mE, while prekallikrein activity from 127 to 187 mE.     

Computer prediction of biological activity spectra for low-molecular peptides and peptidomimetics

The wide variety of the biological effects of peptides and their high activity are the main reasons for the search for new basic drug structures among them. The most promising compounds can be selected using the PASS computer system (Prediction of Activity Spectra for Substances). This system was originally developed to predict the activities of low-molecular "drug-like" organic compounds. Its predictive capacity is described here by the example of 134 peptides and peptidomimetics with nine known biological activities. Its average predictive power is shown to be approximately 97%. Such an accuracy demonstrates that computer prediction can be applied both to the evaluation of effects and mechanisms of action of endogenous and synthetic peptides and to the screening of new therapeutic agents among the most promising basic structures.     

New principles in determining the biological value of proteins

Some new principles are suggested in determination of the protein biological values that take into account the amino acid composition and the processes occurring in the course of protein assimilation. Food proteins have a significant effect on the protein-amino acid metabolism of the organism by reducing oxidative catabolism of essential amino acids which are deficient in the utilized protein, i.e. they have a compensating effect on the deficiency of exogenous essential amino acids. The understanding of the process allowed the author to approach the solution of the problem of the replacement of the amino acid score with the biological value. For this purpose two new parameters which determine the quality and the second phase of protein assimilation have been introduced, i.e. potential biological value (BVp) and compensation coefficient (C), respectively. The experimental biological value (BV) is determined as the sum of the two parameters: BV = BVp + C.     

Computer prediction of biological activity spectra for low-molecular peptides and peptidomimetics

The wide variety of the biological effects of peptides and their high activity are the main reasons for the search for new basic drug structures among them. The most promising compounds can be selected using the PASS computer system (Prediction of Activity Spectra for Substances). This system was originally developed to predict the activities of low-molecular “drug-like” organic compounds. Its predictive capacity is described here by the example of 134 peptides and peptidomimetics with nine known biological activities. Its average predictive power is shown to be approximately 97%. Such an accuracy demonstrates that computer prediction can be applied both to the evaluation of effects and mechanisms of action of endogenous and synthetic peptides and to the screening of new therapeutic agents among the most promising basic structures.